appendix 1: details of systematic search strategies

Appendix 1: Details of systematic search strategies

1.1 Search Terms and Keywords

The keywords were “models of antenatal care” AND “prematurity”, and the following search terms were used across all the databases:

Models of antenatal care: Maternity care OR pregnancy care OR prenatal care OR midwifery care OR nursing care OR nurse-midwifery care OR obstetric care OR midwifery services OR obstetric service OR nurse-midwifery services OR continuity of care OR multidisciplinary team OR midwifery model OR obstetric model OR medical model OR midwifery team OR obstetric team OR medical team OR multidisciplinary team OR shared care OR midwifery led OR nursing led OR obstetric led OR medical led OR midwifery management OR nursing management OR obstetric management OR medical management.

Prematurity: Prematurity OR preterm birth OR preterm labour OR preterm delivery OR premature birth OR premature labour OR premature delivery OR preterm parturition OR premature parturition.

AND and OR were used as Boolean operators and NEAR, NEXT, and ADJ as proximity operators across search strategies.

1.2 Limitations applied to databases

Limitations to females and humans were applied to each electronic database, and Cochrane highly sensitive search filters were used to identify reports of RCTs10. No restrictions were applied regarding the time or publication year. The number of records identified though each database and other resource searches are presented below in table 1.2:

1.3 Details of search strategies

MEDLINE search strategy

1. exp Perinatal Care/ 2. exp Prenatal Care/ 3. exp Midwifery/4. exp Obstetrics/ 5. exp Maternal Health Services/ 6. exp Community Health Services/ 7. exp Home Childbirth/

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Table 1.2: Databases and other resources search results

Details Records identified

MEDLINE 2696

EMBASE 7270

CENTRAL 502

CINAHL 1006

PSHYCINFO 109

WEB OF SCIENCE 1488

BNI 236

OTHER RESOURCES 44

Total 13551

After duplicated removed 11106

8. exp Birthing Centers/ 9. ((midwif* or nurs* or obstetric* or medical*) adj (service* or care)).mp. 10. ((antenatal* or prenatal* or matern* or perinatal* or pregnan* or childbirth* or childbearing*) adj (service* or care)).mp. 11. exp "Continuity of Patient Care"/ 12. exp Nursing Services/ 13. exp Nursing Care/ 14. exp Models, Nursing/ 15. exp Nurse Midwives/ 16. ((nurs* or midwif* or obsteric* or medical*) adj model*).mp. 17. ((nurs* or midwif* or obsteric* or medical*) adj2 team*).mp. 18. (multidisciplinary adj team*).mp. 19. (shar* adj2 care).mp. 20. ((nurs* or midwif* or obsteric* or medical*) adj2 manag*).mp. 21. ((nurs* or midwif* or obsteric* or medical*) adj2 led*).mp. 22. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 23. exp Premature Birth/ 24. exp Obstetric Labor, Premature/ 25. ((preterm* or prematur*) adj2 (birth* or partuit* or deliver* or labo?r)).mp. 26. (prematur* or preterm*).mp. 27. 23 or 24 or 25 or 26 28. 22 and 27 29. randomized controlled trial.pt. 30. controlled clinical trial.pt. 31. randomized.ab. 32. placebo.ab. 33. drug therapy.fs. 34. randomly.ab. 35. trial.ab. 36. groups.ab. 37. 29 or 30 or 31 or 32 or 33 or 34 or 35 or 36 38. exp animals/ not humans.sh. 39. 37 not 38 40. 28 and 39

EMBASE search strategy 1. exp Perinatal Care/ 2. exp Prenatal Care/ 3. exp maternal care/ 4. exp Midwifery/5. exp Obstetrics/ 6. exp Maternal Health Services/ 7. exp Home Childbirth/ 8. exp Community Health Services/ 9. exp Home Childbirth/ 10. exp Birthing Centers/ 11. ((midwif* or nurs* or obstetric* or medical*) adj (service* or care)).mp. 12. ((antenatal* or prenatal* or matern* or perinatal* or pregnan* or childbirth* or childbearing*) adj (service* or care)).mp. 13. exp "Continuity of Patient Care"/ 14. exp Nursing Services/ 15. exp Nursing Care/ 16. exp Nurse Midwives/ 17. ((nurs* or midwif* or obsteric* or medical*) adj2 team*).mp. 18. ((nurs* or midwif* or obsteric* or medical*) adj model*).mp. 19. (shar* adj2 care).mp. 20. (multidisciplinary adj team*).mp. 21. ((nurs* or midwif* or obsteric* or medical*) adj2 manag*).mp. 22. ((nurs* or midwif* or obsteric* or medical*) adj2 led*).mp. 23. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 24. exp Premature Birth/ 25. exp Obstetric Labor, Premature/ 26. ((preterm* or prematur*) adj2 (birth* or partuit* or deliver* or labo?r)).mp.

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27. (prematur* or preterm*).mp. 28. exp prematurity/ 29. 24 or 25 or 26 or 27 or 28. 30. 23 and 29 31. random*.mp. 32. controlled clinical trial.pt. 33. randomized.ab. 34. factorial*.mp. 35. crossover*.mp. 36. cross-over*.mp. 37. cross over*.mp. 38. placebo*.mp. 39. (doubl* adj blind*).mp. 40. crossover procedure/ 41. double blind procedure/ 42. randomized controlled trial/ 43. single blind procedure/ 44. 31 or 32 or 33 or 34 or 35 or 36 or 37 or 38 or 39 or 40 or 41 or 42 or 43 44. 30 and 44

CENTRAL search strategy

#1. MeSH descriptor: [Prenatal Care] this term only #2. MeSH descriptor: [Perinatal Care] this term only #3. MeSH descriptor: [Obstetrics] this term only #4. MeSH descriptor: [Midwifery] this term only #5. MeSH descriptor: [Maternal Health Services] this term only #6. MeSH descriptor: [Community Health Services] this term only #7. MeSH descriptor: [Home Childbirth] this term only #8. MeSH descriptor: [Birthing Centers] this term only #9. (midwif* or nurs* or obstetric* or medical*) near/2 (service* or care) #10. (antenatal* or prenatal* or matern* or perinatal* or pregnan* or childbirth* or childbearing*) near/2 (service* or care) #11. MeSH descriptor: [Continuity of Patient Care] this term only #12. MeSH descriptor: [Nursing Services] this term only #13. MeSH descriptor: [Nursing Care] this term only #14. MeSH descriptor: [Nurse Midwives] this term only #15. MeSH descriptor: [Models, Nursing] this term only #16. MeSH descriptor: [Obstetric Nursing] this term only #17. (nurs* or midwif* or obsteric* or medical*) near/2 model* #18. (nurs* or midwif* or obsteric* or medical*) near/2 team* #19. multidisciplinary near team* #20. (shar* near/2 care) #21. (nurs* or midwif* or obsteric* or medical*) near/2 manag* #22. (nurs* or midwif* or obsteric* or medical*) near/2 led* #23. #1 or #2 or #3 or #4 or #5 or #6 or #7 or #8 or #9 or #10 or #11 or #12 or #13 or #14 or #15 or #16 or #17 or #18 or #19 or #20 or #21 or #22 #24. MeSH descriptor: [Premature Birth] this term only #25. MeSH descriptor: [Obstetric Labor, Premature] this term only #26. (preterm* or prematur*) near/2 (birth* or partuit* or deliver* or labo?r) #27. (prematur* or preterm*) #28. #24 or #25 or #26 or #27 #29. #23 and #28

CINHAL search strategy

S1. (MH "Perinatal Care") S2. (MH "Perinatal Nursing") S3. (MH "Prenatal Care") S4. (MH "Maternal Health Services+") S5. (MH "Midwifery+")S6. (MH "Midwifery Service+") S7. (MH "Nurse-Midwifery Service") S8. (MH "Midwifery Service+")

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S9. (MH "Obstetric Care+") S10. (MH "Obstetric Service”) S11. (MH "Obstetric Nursing")S12. (MH "Community Health Services+") S13. (MH "Home Childbirth") S14. (MH "Childbearing Care (Iowa NIC) (Non-Cinahl)+") S15. (MH "Alternative Birth Centers") S16. (midwif* OR nurs* OR obstetric* OR medical*) AND (service* OR care) S17. antenatal* or prenatal* or matern* or perinatal* or pregnan* or childbirth* or childbearing*) AND (service* or care) S18. (MH "Continuity of Patient Care+") S19. (MH "Nursing Service") S20. (MH "Midwives+")S21. (nurs* or midwif* or obsteric* or medical*) AND model* S22. (nurs* or midwif* or obsteric* or medical*) N2 team* S23. (MH "Multidisciplinary Care Team+”) S24. multidisciplinary AND team* S25. shar* N2 careS26. (nurs* or midwif* or obsteric* or medical*) N2 manag* S27. (nurs* or midwif* or obsteric* or medical*) N2 led* S28. S1 OR S2 OR S3 OR S4 OR S5 OR S6 OR S7 OR S8 OR S9 OR S10 OR S11 OR S12 OR S13 OR S14 OR S15 OR S16 OR S17 OR S18 OR S19 OR S20 OR S21 OR S22 OR S23 OR S24 OR S25 OR S26 OR S27S29. (MH "Childbirth, Premature") S30. (MH "Labor, Premature”) S31. (preterm* or prematur*) N2 (birth* or partuit* or deliver* or labo?r) S32. prematur* or preterm* S33. S29 OR S30 OR S31 OR S32 S34. S33 AND S28S35. TX allocat* random* S36. (MH "Quantitative Studies") S37. (MH "Placebos") S38. TX placebo* S39. TX random* allocat* S40. (MH "Random Assignment”) S41. TX randomi* control* trial* S42. TX ( (singl* n1 blind*) or (singl* n1 mask*) ) or TX ( (doubl* n1 blind*) or ( doubl* n1 mask*) ) or TX ( (tripl* n1 blind*) or (tripl* n1 mask*) ) or TX ( (trebl* n1 blind*) or (trebl* n1 mask*) ) S43. TX clinic* n1 trial* S44. PT Clinical trial S45. (MH "Clinical Trials+”) S46. S35 OR S 36 OR S37 OR S38 OR S39 OR S40 OR S41 OR S42 OR S43 OR S44 OR S45 S47. S34ANDS46

PSHYC INFO search strategy 1. exp Perinatal Period/ 2. exp Prenatal Care/ 3. exp Midwifery/4. exp Obstetrics/ 5. exp Integrated Services/ 6. ((midwif* or nurs* or obstetric* or medical*) adj (service* or care)).mp. 7. ((antenatal* or prenatal* or matern* or perinatal* or pregnan* or childbirth* or childbearing*) adj (service* or care)).mp. 8. exp "Continuum of Care"/ 9. exp Public Health Service Nurses/ 10. ((nurs* or midwif* or obsteric* or medical*) adj model*).mp. 11. ((nurs* or midwif* or obsteric* or medical*) adj2 team*).mp. 12. (multidisciplinary adj team*).mp. 13. (shar* adj2 care).mp. 14. ((nurs* or midwif* or obsteric* or medical*) adj2 manag*).mp. 15. (nurs* or midwif* or obsteric* or medical*) adj2 led*).mp. 16. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 17. exp Premature Birth/ 18. ((preterm* or prematur*) adj2 (birth* or partuit* or deliver* or labo?r)).mp. 19. (prematur* or preterm*).mp.

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20. 17 or 18 or 19 21. 16 and 20 22. limit 21 to human 23. Treatment Effectiveness Evaluation.mp. 24. Treatment Outcomes.mp. 25. Placebo.mp. 26. Followup Studies.mp. 27. placebo*.mp. 28. random*.mp. 29. comparative stud*.mp. 30. (clinical adj3 trial).mp. 31. (research adj3 design).mp. 32. (evaluat* adj3 stud*).mp. 33. (prospectiv* adj3 stud*).mp. 34. ((singl* or doubl* or trebl* or tripl*) adj3 (blind* or mask*)).mp. 35. exp Treatment Outcomes/ 36. 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or 32 or 33 or 34 37. 22 and 36

WEB OF SCIENCE search strategy #1. TS=((antenatal* or prenatal* or matern* or perinatal* or pregnan* or childbirth* or childbearing* or community) NEAR/2 (service* or care)) #2. TS=((midwif* or nurs* or obstetric* or medical*) NEAR/2 (service* or care)) #3. TS= (nurse* AND midwif*) #4. TS= ((nurs* or midwif* or obsteric* or medical*) NEAR/2 model*) #5. TS= ((nurs* or midwif* or obsteric* or medical*) NEAR/2 team*) #6. TS=(multidisciplinary NEAR/2 team*) #7. TS= (shar* NEAR/2 care) #8. TS= ((nurs* or midwif* or obsteric* or medical*) NEAR/2 manag*) #9. TS= ((nurs* or midwif* or obsteric* or medical*) NEAR/2 led* ) #10. #9 OR #8 OR #7 OR #6 OR #5 OR #4 OR #3 OR #2 OR #1#11. TS= ((preterm* or prematur*) NEAR/2 (birth* or partuit* or deliver* or labo?r)) #12. TS= (prematur* or preterm*) #13. #12 OR #11 #14. #13 AND #10 #15. TS= clinical trial* OR TS=research design OR TS=comparative stud* OR TS=evaluation stud* OR TS=controlled trial* OR TS=follow-up stud* OR TS=prospective stud* OR TS=random* OR TS=placebo* OR TS=(single blind*) OR TS=(double blind*) #16. #15 AND #14

BNI search strategy

S1. ((antenatal* OR prenatal* OR mater* OR perinatal* OR pregnan* OR childbirth* OR childbearing*) NEAR/2 (service* OR care)) S2. ((midwife* OR nurse* OR obstetric* OR medical*) NEAR/2 (service* OR care))! S3. ((nurs* OR midwif* OR obsteric* OR medical*) NEAR/2 model*) ! S4. ((nurs* OR midwif* OR obsteric* OR medical*) NEAR/2 team*) S5. (multidisciplinary NEAR/2 team*) S6. (shar* NEAR/2 care) S7. ((nurs* OR midwif* OR obsteric* OR medical*) NEAR/2 manage*) S8. ((nurs* OR midwif* OR obsteric* OR medical*) NEAR/2 led*) S9. S1 OR S2 OR S3 OR S4 OR S5 OR S6 OR S7 OR S8S10. ((pretermit* OR premature*) NEAR/2 (birth* OR partuit* OR deliver* OR labor)) S11. (prematur* OR preterm*) S12. S11 OR S10S13. S12 AND S9

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Appendix 2: Validity Inclusion Assessment

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*Primary reference for the study. ** Numbers of participants randomised to each group not reported. *** Controlled before and after study with less than two intervention and control reported. **** Outcome measures not meeting inclusion criteria. *****Interrupted time series sites.

STUDY ID AUTHOR NAMES

PRIMARY ASSESSMENT

SECONDARY ASSESSMENT

ACTIONStudy design Methodology

RCTThe quantitative measurement of health and patient outcomes

Relevant and interpretable data presented/obtainable

Begley 2011 Begley et al., 2011 Done Done Done Include

Biro 2000 *Biro et al. 2000 Biro et al. 2003

Done Done Done Include

Breazley 2001 Breazley et al. 2001 Done Unclear Unclear Exclude**

Conover 2001 Conover et al. 2001 Not done N/A N/A Exclude***

Collaborative Group 1993 *Collaborative Group 1993 Done Done Done Include

Goldenberg 1990 Goldenberg et al. 1990 Done Done Done Incude

Harvey 1996 Harvey et al. 1996 Done Done Unclear Exclude****

Hobel 1994 Hobel et al. 1992 Ross et al. 1992 *Hobel et al. 1994 Ross et al. 1994


Homer 2001 Homer et al. 2000 Homer et al. 2001a Homer et al. 2001b Homer et al. 2002

Done Done Unclear Exclude****

Iams 1989 *Iams et al. 1989 Johnson, 1989


Klerman 2001 Klerman et al. 2001 Done Done Done Include

Konte 1988 Konte et al. 1988 Not done N/A N/A Exclude*****

MacVicar 1993 MacVicar et al. 1993 Done Done Done Include

Main 1989 *Main et al. 1989 Main et al. 1985


McLachlan 2012 McLachlan et al. 2008 McLachlan et al. 2011a McLachlan et al. 2011b *McLachlan et al 2012a McLachlan et al. 2012b


Mueller-Heubach 1989 Mueller-Heubach,, 1989 *Mueller-Heubach et al. 1989 Mueller-Heubach and Guzick,1985

Done Done Unclear Exclude**

North Staffordshire 2000 North Staffordshire 2000 Done Done Unclear Exclude****

Rowley 1995 Rowley et al. 1995 Done Done Done Include

Tracy 2013 Tracy et al. 2011 *Tracy et al. 2013


Tucker 1996 Ratcliffe et al. 1996 *Tuckler et al. 1996


Turnbull 1996 Holmes et al. 1996 Shields et al. 1997 Shields et al. 1998 *Turnbull et al. 1996 Young et al. 1997


Appendix 3: Characteristics of included studies

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Begley 2011

Methods Study design: RCT Primary purpose: to compare midwife-led care (MLC) versus consultant led care (CLC) for healthy, pregnant women without risk factors Intervention delivery: midwives. Baseline measurements: age, parity, marital status, weight and height. Power calculation: based on a power of ≥ 80% (probability of being significant) to detect differences of at least 6% between CLC and MLC in midwifery-led units (MLU) in rates of induction of labour (23% to 17%), episiotomy (31% to 24%) and augmentation of labour (24.4% to 17.9%) at the 5% significance level. ITT: Yes. Definition of PTB: A birth considered preterm if gestation < 37 weeks. Duration of study: 2004-2007

Participants Setting: Health Service Executive, Dublin, Republic of Ireland. Inclusion criteria: women were eligible for trial entry if they were: (a) healthy with no risk factors for complications for labour and delivery as identified in the ‘Midwifery-led Unit (Integrated) Guidelines for Practitioners’ (at http://www.nehb.ie/midu/ guidelines.htm); (b) aged between 16 and 40 years old; and (c) within 24 completed weeks’ gestation Exclusion criteria: women with risk factors Risk Assessment criteria: Not applicable Total number of participants randomised: 1653; 1101 to MLC group and 552 to CLC group. Loss to follow up: MLC group = 5 and CLC group =3 Mean age of participants at first visit (years): MLC group = 29 ± 4.9 and 28.7 ± 5.0 to CLC group Mean gestational age at first visit (weeks): Not stated.Gravidity. First pregnancy (%): MLC group =63.7% ;CLC group =61% Multiple pregnancies: Not reported. Parity (%): Women with parity 0: MLC group = 565 (51.3%) and CLC group = 276 (50%) Women with parity > 0: MLC group = 536 (48.7%);CLC group=276 (50%) Previous PTB: MLC group =32 (7.1%); CLC group=26 (5.2%) Ethnicity: Not stated. Marital status (%): Single women: MLC group = 37.7% and CLC group = 41.5% Married, not separated women: MLC group = 60.3%; CLC group =56.5% Socio-economic status: Income < $20,000 Aust per year: MLC group =28.5% ;CLC group =25.9%Education:High school to year 12: MLC group =62.8% ;CLC group =62%Other health behaviours. Smoking (%): MLC=34.6% ;CLC=36.4%

Intervention Type of intervention treatment: MLC Content of intervention: women received antenatal care from midwives and, if requested, from their GPs for few visits. When complications become apparent and based on agreed standard, the care of women was transferred to CLC. Intrapartum care was provided by midwives in a MLU with transfer to the consultant led unit (CLU) if required. Midwives provided the postnatal care in the MLU for up to 2 days, with transfer of women or neonates to CLU if appropriate. After discharge, midwives from the MLU visited at home, and/or provided postpartum telephone support for up to 7 days. Type of control treatment: CLC Content of control: women received standard care antenatal care provided by obstetricians with support of the midwifery and medical team. Intrapartum and postpartum care were provided by midwives with supervision of consultants. Women were discharged into the care of the Public Health Nurse.

Outcomes Outcomes considered in the review and reported in or extracted from the study: Antenatal hospitalisation. 5-minute Apgar score below or equal to 7 Admission to special care nursery/NICU Breastfeeding initiation Caesarean birth Fetal loss/neonatal death before 24 weeks Fetal loss/neonatal death equal to/after 24 weeks Induction of labour Instrumental vaginal birth (forceps/vacuum) Low birthweight (< 2500 g) Overall fetal loss and neonatal death Preterm labour (< 37 weeks) Spontaneous vaginal birth (as defined by trial authors)

Notes Women were randomised to MLU or CLU in a 2:1 ratio.

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Biro 2000

Methods Study design: RCT Primary aim: to compare a new model of team midwifery care with standard maternity care. Intervention delivery: midwifery staff. Baseline measurements: age at booking, gestation at booking, parity, marital status, place of birth, secondary school attendance. Power calculation: based on ≥ 81% power to detect an increase in spontaneous vaginal delivery rates from an expected 63 to 73% with a corresponding decrease in operative deliveries rates from 37 to 27% assuming 30% attrition. ITT: Yes. Definition of PTB: less than 37 weeks. Duration of study: 1996-1998

Participants Settings: Public tertiary hospital, Monash Medical Centre, Melbourne, Australia. Inclusion criteria: women at low and high risk of complications were eligible to participate in the trial. Exclusion criteria: women who solicited shared care with obstetricians, pregnant women required care in the fetal medicine unit, were more than 24 weeks’ gestation or did not speak English. Risk Assessment criteria: Not reported. Total number of participants randomised: 1000; 498 to standard care group and 502 to midwifery team group. Loss to follow up: team care= 14 and standard care= 18 Mean age of participants at first visit (years): team care= 28.2±5.2 and standard care= 28.3±5.4 Mean gestational age at first visit (weeks): team care= 14.3±2.7 and standard care= 14.1±2.9 Gravidity: Not reported. Parity: Women with parity 0: team care= 320±63.7 and standard care= 304+61.0 Multiple pregnancies (twins): team care= 12 and standard care= 13 Previous PTB: Not reported. Ethnicity: Not stated. Marital status: Married: team care= 338±67.3 and standard care= 360±72.3 Socio-economic status: Not stated. Education: Participants attending secondary school to year 12: team care= 297±61.6 and standard care 298±61.3 Other health behaviours: Not stated.

Interventions Type of intervention treatment: midwifery team care. Content of intervention: seven full-time midwives provided antenatal, intrapartum, and also some hospital-based postnatal care in consultation with medical staff. Doctors collaborated with the midwifery team and saw women at 12 to16, 28, 36 and 41 weeks. An individual care plan was provided to women with at high risk of complications. Type of control treatment: standard maternity care Content of control: diverse alternatives of care including: care by hospital obstetric personnel; shared care between hospital obstetric staffs and midwives in a community health centre; shared care between hospital obstetric personnel and GPs in the community; and care by hospital midwives jointly with obstetric staff (less frequent). Women in the control group experienced an inconsistent level of continuity of care during their pregnancy, from seeing the same midwife or doctor in most visits to seeing several midwives and doctors.

Participants Outcomes of interest considered in this review and reported in or extracted from the study outcomes: 5-minute Apgar score below or equal to 7 Admission to special care nursery/NICU Caesarean birth Fetal loss/neonatal death before 24 weeks Fetal loss/neonatal death equal to/after 24 weeks Induction of labour Instrumental vaginal birth(forceps/vacuum) Mean length of neonatal hospital stay (days) Overall fetal loss and neonatal death Preterm birth (< 37 weeks) Spontaneous vaginal birth (as defined by trial authors)

Notes Both groups similar at baseline. The midwife attending labour was known by 80% and 0.3% of experimental group and standard group respectively.

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Collaborative Group 1993

Methods Study design: Multicenter RCT Primary aim: to evaluate the effects of a PTB prevention programme in five different centres in five different geographic areas serving primarily low-income populations of various ethnic groups. Intervention delivery: specialist nurses and medical staff. Baseline measurements: maternal age, race, being a public or private patient, twin pregnancy, preterm labour in previous pregnancy and at least one first- or second- semester abortion in previous pregnancies. Power calculation: initially it was planned to include at least 200 singleton or twin gestation participants per group, at each centre to detect a decrease of 10% to 20% in spontaneous PTB rates, based on 75% power and the 5% significance level. However, the power of the study ranged from about 60% at centre 2 up to 95% at centre 1, when the value of continuing the study for another year to reach the sample size goals at all centres was judged not to be worth the cost. ITT: No. Definition of PTB: birth before 37 completed weeks’ gestation. Duration of study: 1983-1986

Participants

Intervention Type of intervention treatment: PTB prevention programme care. Content of intervention: women had weekly visits scheduled after 20 to 24 weeks’ gestation at the specific medical centres. At these visits, women received routine obstetric care, including pelvic examinations to determine the status of the cervix, and patient education both provided by specially instructed staff. The programme included education regarding the subtle symptoms of PTB, the importance of early detection of preterm labour and self detection of uterine contractions, weekly, reinforcement of woman’s cooperation and awareness with educational handouts, a weekly questioning concerning the presence or absence of preterm labour symptoms or uterine activity, and ultrasonographic examination of any women for whom the length of gestation was in question. A nurse coordinator at each institution received formal training regarding the PTB prevention programme before the intervention was implemented in the trial. In addition, attending physicians, residents, staff nurses of both the clinics and hospitals, as well as nurse-practitioners and those personnel responding to patient telephone calls, received an in-service teaching programme at all centres. Type of control treatment: routine antenatal care. Content of control: women received routine obstetric care in the originating medical centre and provided by the same trained staff.

Settings: five medical centres with seven hospitals within the USA: Northwester University Medical School, The Ohio State University, The University of Alabama in Birmingham (University Hospital and Cooper Green Hospital), University of California at San Diego and Vanderbilt University (Nashville General Hospital and Vanderbilt University Hospital). The University of California at San Francisco served as the site of data management and analysis for the trial. Inclusion criteria: pregnant women were eligible for trial entry if they were classified as high-risk based on use of the Creasy Scoring system and were seen before 32 or 34 weeks’ gestation (depending on the centre). Risk assessment criteria: The Creasy Scoring system for the risk of PTB was computed by addition of the number of points given to four specific items on a screening questionnaire, which was filled out for all women at the first prenatal visit. Women with a score of 0-10 were classified as low risk and re-screened at 20 to 26 weeks if entered care before 22 weeks; and women with a score of ≥10 were classified as high risk. A woman’s score could be updated with a newly detectable change in her risk before 34 week’ gestation, unless preterm labour occurred within 72 hours of the risk status change. Women whose risk never reached 10 points formed the low-risk group; high risk women refusing to participate in the study formed the high risk refused group, and high risk women seen after 32 or 34 weeks’ gestation formed the high risk ineligible group. Exclusion criteria: women excluded from risk assessment were defined at each centre: maternal transport patients at all five centres; private patients at centres 1, 4 and 5; adolescents at centre 2; and those with medical pregnancy complications (i.e diabetes mellitus) at centre 4. and high-risk women at more than 32-34 weeks’ at all centres. Total number of participants randomised in all five centres: 2395; 1200 to intervention group (IG) and 1195 to control group (CG). Randomised women by centre and group: Centre 1: 937 women randomised (474 to IG and 463 to CG) Centre 2: 286 women randomised (143 to IG and 143 to CG) Centre 3: 370 women randomised (185 to IG and 185 to CG) Centre 4: 433 women randomised (219 to IG and 214 to CG) Centre 5: 369 women randomised (179 to IG and 190 to CG) Loss to follow ups: Not reported. Mean age of participants and gestational age at first visit: Not reported. Gravidity and parity: Not reported.. Multiple pregnancies (%) : IG= 5.5% and CG= 5.2% Parity: Not stated. Marital status: Not stated. Socio-economic status: Low income population Other health behaviours: Not stated. Previous PTB and ethnicity by centre and group:

!

Ethnic Group:! Black! Hispanic! White! Other

!72%! 0%!28%! 0%

!72.8%

0%!27.2%! 0%

!43.8%!10.2%!42.6%!

0%

!41.8%!15.6%!46.0%!

0%

!60.1%!

0%!39.9%

0%

!64.8%!

0.0%!35.2%!

0%

!37.4%!

0%!62.6%!

0%

!37.1%!

0%!62.9%!

0%

!6.7%!

57.5%!31.8%!

3.9%

!5.8%!

67.2%!21.2%!

5.8%

!44.0%!13.6%!41.0%

0.8%

!44.5%!16.6%!38.5%!

1.2%

Obstetric risk:! Previous PTB! Twin births!

!45.4%!

4.0%!

!40.0%!

5.0%!

!77.6%!

9.8%!

!69.9%!

8.4%!

!50.3%!

7.0%!

!60.8%!

3.8%!

!35.3%!

2.3%!

!35.5%!

1.9%!

!40.2%!

4.5%!

!42.9%!6.8%7!

!49.8%!

5.5%!

!49.8%!

5.2%!

Centre 1 Centre 2 Centre 3 Centre 4 Centre 5 Means

IG CG IG CG IG CG IG CG IG CG IG CG

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Collaborative Group 1993 (continued)

Outcomes Outcomes considered in the review and reported in or extracted from the study: Preterm birth (< 37 weeks) Low birthweight (< 2500g)

Notes A site visit was made, for 2 to 3 days at each centre, by a nurse trained in the PTB programme, to enhance the similarity of the intervention at difference sites. Substantial adjustments for patient risks of PTB and centre-specific process measures go care, other than hospital admission rates, did not help to explain the significant site-specific intervention effects on PTB outcomes. Around 95% of all women admitted into the hospital with preterm labour admissions were considered to meet the study criteria for spontaneous PTB.

Goldenberg 1990

Methods Study design: RCT Primary aim: to evaluate the effects of a specific approach to PTB prevention in a predominantly black-indigent population. Intervention delivery: project nursing staff as primary care givers. Baseline measurements: maternal age, parity, race, risk score, previous spontaneous or indicated PTB. Power calculation: Not done. ITT: No. Definition of PTB: birth before 37 or before 37 completed weeks’ gestation. Duration of study: 1982-1986.

Participants Settings: the Jefferson County Health Department System, Alabama, USA. Inclusion criteria: women who registered for prenatal care in this centre were eligible for trial entry if they (a) had an estimated date of delivery between 1st November 1982 and 1st April 1986 and (b) were classified as high-risk based using of the Creasy Scoring system. Risk assessment criteria: Women were screened using the Creasy Scoring system as soon as after enrolment for prenatal care and between 22-26 weeks’ gestation. Women were classified as high-risk based on a score of 10 or more on the screening questionnaire and were invited to participate in the project. Women with an score of less than 10 were considered low risk. Three subgroups were included in the analysis: low risk women, high risk women who refused to participate and high risk ineligible women (i.e could not be contacted, were private patients or not Jefferson county residents). Exclusion criteria: women were excluded if they were more than 30 weeks’ gestation at booking. Total number of participants randomised: 969; 491 to PTB prevention project care and 478 to standard care. Loss to follow up: Not stated Age of participants by age group (%): <20 years: PTB prevention project= 34.3% and standard care= 37.2% 20-34 years: PTB prevention project= 61.5%; and standard care= 58.4% ≥35 years: PTB prevention project= 4.1% and standard care= 4.4% Mean gestational age at first visit: Not stated Gravidity: Not stated Parity (%): 0: PTB prevention project= 34.4% and standard care= 39.1% 1: PTB prevention project= 29.9% and standard care= 27.4% >2: PTB prevention project= 35.6% and standard care= 33.5% Previous PTB: PTB prevention project= 37.1% and standard care= 29.1% and 32.2% respectively. Multiple pregnancies (%): Project=17 (3.5%) and standard care= 20(4.2%) Ethnicity (%) Black: PTB prevention project= 71.5% and standard care= 72.6% White: PTB prevention project= 28.1% and standard care= 27.4% Marital status: Mostly single. Socio-economic status: All poor. Education: Not stated. Other health behaviours: Not stated.

Intervention Type of intervention treatment: PTB prevention project care Content of intervention: high risk women received prenatal care provided by specially trained clinical-nurses, who generally saw the same woman at each visit in a clinic facility separated from the usual health department clinic, where control women received their care. Women were scheduled to be seen weekly from 22 weeks’ gestation according to the study protocol. They received intensive observation, including cervical examinations and detailed education about preterm labour signs and symptoms. Women in labour or those concerned about the possibility of PTB were managed by resident staff under faculty supervision either at the The University of Alabama Hospital or its county affiliate Cooper Green Hospital. They used standard protocols for the diagnosis and management of preterm labour. Type of control treatment: standard care Content of control: high-risk control women received prenatal care in their usual health department clinic. Low risk women, high risk refusers and high risk ineligible women were also seen at this clinic. Any hospital encounter was managed by resident staff under consultant supervision.

Outcomes Outcomes considered in the review and reported in or extracted from the study: Admission to special care nursery/NICU Low birthweight (< 2500 g) Overall fetal loss and neonatal death Preterm birth (< 37 weeks)

Notes Approximately 70% of the study population was Black and about 20% were younger than 20 years. The PTB rates appeared to raise in all groups during the project. This was largely associated to the greater reliance on ultrasound for gestational age determination.

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Hobel 1994

Methods Study design: Cluster RCT Primary aim: to evaluate the effects of a PTB prevention project and test whether PTB prevention education with increased clinic visits and selected prophylactic interventions reduce PTB. Intervention delivery: nurse-practitioners, nutritionists, social workers, public health nurses, and health educators. Baseline characteristics: age, marital status, gravity, parity, previous preterm birth. Power calculation: originally estimated to have a power of 85% for detecting a 30% decrease in PTB rates on the basis of an expected control high-risk rate of 11%. The control clinic preterm rate in the study turned out to be only 9% and the study had a power of 77% for detecting a 30% decrease in PTB rates. A PTB rate of 8.3% was assumed in the experimental clinic control group, which reflected a 25% reduction when compared with that of the high-risk patients in the control clinics. ITT: Yes. Definition of PTB: A birth considered preterm if gestation < 37 week. Duration of study: 1983-1988

Participants Settings: eight West Los Angeles prenatal county clinics, USA. Inclusion criteria: women were eligible to participate in the trial if they attended one of the participating intervention clinics, and were (a) English- or Spanish-speaking; (b) had a gestational age of < 31 weeks at time of first visit; (c) did not have any disabling condition and signed an informed consent; (d) and were classified as being at high risk for PTB at their second clinic visit on the basis of a specific risk assessment system. Risk assessment criteria: The risk assessment tool derived from the same population before the initiation of the study (Ross, 1986) and classified women were classified at at high risk of PTB if they had one or more of the following historical and developing risk factors: induced abortion, previous neonatal death, habitual abortion (3 or more spontaneous), previous PTB, uterine cervical, abnormality, previous classic cesarean section, previous myomectomy, chronic hypertension, renal disease, psychiatric hospitalisation, tobacco (more than 10 cigarettes/day within past year), marijuana or narcotics use, size-date discrepancy (>3 cm size from dates) or unknown last menstrual period, severe anaemia, threatened abortion (bleeding before 20 weeks), incompetent cervix, surgery requiring hospitalisation, multiple pregnancy, mild or severe pregnancy-induced hypertension, bleeding after 20 weeks or hospitalised for preterm labor. Women with none of these risk factors were classified as low risk. Exclusion criteria: women with cardiac disease, hyperthyroidism, diabetes, asthma (on medication), seizures or epilepsy, drug sensitivity to Provera, history of deep vein thrombosis or thromboembolic disease, liver disease, malignancy of breast or genital organs, any disability causing inability to follow directions, attempted suicide (during pregnancy). Total number of participants randomised: 2054 women attending any of eight West Los Angeles County prenatal clinics randomised to be either experimental (five) or control clinics (three). Women in PTB prevention clinics (experimental clinics) = 1174 and women in the control clinics = 880. Loss to follow up: Not stated. Mean age of participants at first visit (years): PTB clinic= 25.9 ± 5.6 and control clinic = 26.3 ± 5.7 Mean gestational age at first visit (weeks): PTB clinic= 19.1 ± 7.1 and control clinic = 19.7 ± 7.1 Gravidity: PTB clinic= 2.4 ± 2.0 and control clinic = 2.6 ± 2.1 Parity: PTB clinic= 1.5 ± 1.7 and control clinic = 1.46 ± 0.7 Multiple pregnancies: PTB clinic= 7and control clinic = 12 Previous PTB: PTB clinic= 37.1% and control clinic = 32.2% Education (%): Less than high school: PTB clinic= 65.2 and control clinic = 73.5 High school or more: PTB clinic= 34.8 and control clinic = 26.5 Ethnicity (%): Hispanic: PTB clinic= 71.2 and control clinic = 78.9 White: PTB clinic= 15.9 and control clinic = 11.2 Black: PTB clinic= 8.1and control clinic = 8.5 Asian: PTB clinic= 4.8 and control clinic = 1.4 Marital status (%): Married: PTB clinic= 56.6 and control clinic = 54.5 Single: PTB clinic= 40.3 and control clinic = 41.3 Other health behaviours: Not stated

Intervention Type of intervention treatment: PTB prevention project care Content of intervention: high risk women received prenatal care primarily provided by specially trained clinical-nurses, who generally saw the same woman at each visit in a clinic facility separated from the usual health department clinic where control women received their care. Women were scheduled to be seen weekly from 22 weeks’ gestation according to the study protocol. They received intensive observation, including cervical examinations and detailed education about preterm labour signs and symptoms. Women in labour or those concerned about the possibility of PTB were managed by resident staff under faculty supervision either at the The University of Alabama Hospital or its county affiliate Cooper Green Hospital; using standard protocols for the diagnosis and management of preterm labour. Type of control treatment: standard care Content of control: high-risk control women received prenatal care in their usual health department clinic, where also low risk women, high risk resusers and high risk ineligible women were seen. Intrapartum care or any hospital encounter was also managed by hospital resident staff under consultant supervision.

Outcomes Outcomes of interest considered in this review and reported or extracted from the study outcomes: Low birthweight (< 2500g) Preterm births ( < 37 week)

Notes The majority of the participants were Hispanic. Only three factors differing between women in experimental and control clinics were related to PTB status (the number of high-risk problems, gravidity and mother’s education)

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Iams 1989

Methods Study design: RCT Primary aim: to compare routine antepartum care versus routine antepartum care plus a preterm birth prevention clinic. Intervention delivery: not clearly stated. Baseline measurements: not stated. ITT: No. Power calculation: not done. Definition of PTB: birth of less than 37 weeks’ gestation. Duration of study: 1983-1986

Participants Settings: prenatal clinic at the Department of Obstetrics and Gynaecology at the Ohio State University, Columbus, Ohio, USA. Inclusion criteria: pregnant women considered at high risk for preterm birth based on use of the Creasy Scoring system. Women were selected from 2829 women attending the clinic. Risk assessment criteria: Not stated Exclusion criteria: not stated. Total number of participants randomised: 370: 188: routine antepartum care 182: routine antepartum care + the PTB clinic. Loss to follow up: Not stated Mean age of participants at first visit: Not stated Mean gestational age at first visit: Not stated Gravidity: Not stated Parity: Not stated Previous PTB: Not stated Ethnicity: White vs. African American Marital status: Not stated Socio-economic status: Not stated Education: Not stated Other health behaviours: Not stated.

Intervention Type of intervention treatment: routine antepartum care and a PTB prevention clinic. Content of intervention: women were taught the symptoms and signs of labour were taught and their cervix was examined at weekly visits between 20 and 36 weeks' gestation. Type of control treatment: routine antepartum care. Content of control: not stated.

Outcomes Outcomes considered in the review and reported in or extracted from the study: Preterm birth (< 37 weeks)

Notes This multi centre RCT was presented as a poster at the Society of Maternal Fetal Medicine annual meeting in New Orleans but was never published. Details of ethnic groups were personally provided by one of the authors.

Klerman 2001

Methods Study design: RCT Primary aim: to evaluate whether augmented prenatal care for high-risk African American women improves pregnancy outcomes and patients’ knowledge of risks, satisfaction with care, and behaviour. Intervention delivery: nurses and trained professionals with extensive community experience. Baseline measurements: age, marital status, education, parity, gestational age at booking and maternal risk factors. Power calculation: based on a power of 80%, a sample size of 285 women in the experimental group and a similar number of controls were adequate to detect a rate reduction of LBW babies from 20%–25% to 10%–12%. ITT: No. Definition of PTB: birth of ≤ 36 weeks’ gestation. Duration of study: 1994-1996

Participants Setting: Public tertiary hospital, Jefferson County Department of Health, Alabama, United States. Inclusion criteria: women were eligible for trial entry if they were (a) African-American, Medicaid-eligible pregnant women; (b) aged at least 16 years old; (c) less than 26 weeks’ gestation; (d) with a score of 10 or higher on a risk assessment scale. Risk assessment criteria: The risk assessment scale assigned 10 points to a woman for each factor in a first group: prior PTB, pre-pregnancy weight ≤50 kg, no automobile for transportation; and 5 points for each in a second group: previous full-term low-birthweight infant, smoking at the time of pregnancy; body mass index (BMI - calculated as weight in kilograms divided by the square of height in meters) of less than 19.8 for women who weighed more than 50 kg; and perceived lack of mastery, ascertained by agreement with the statement “There is little that I can do to change many of the important things in my life”. To be eligible for study participation, a woman needed to have at least 1 of the factors in the first group or at least 2 in the second.

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Klerman 2001 (continued)

Participants Exclusion criteria: women with alcoholism, substance abuse, asthma, cancer, diabetes, epilepsy, hypertension, sickle cell disease, HIV/AIDS. Total number of participants randomised: 619; 318 to augmented prenatal care and 301 to usual prenatal care. Loss to follow up: Not stated Age of participants at first visit by age group (%): 16–19: augmented care = 29.6 and usual care= 27.6 20–29: augmented care = 60.4 and usual care= 61.5 ≥30: augmented care = 10.1 and usual care= 11.0 Mean gestational age at first visit (weeks): augmented care= 10.9 ± 4.6 and usual care= 10.7 ± 4.5 Gravidity: Not stated Parity (%): 0: augmented care = 41.2 and usual care= 42.2 1: augmented care = 33.3 and usual care= 33.2 2 or more: augmented care= 25.5 and usual care= 24.6 Previous PTB: Augmented care= 14.5 Usual care= 15.3 Multiple pregnancies: Not stated Ethnicity: African American Marital status (not married) (%): Augmented care= 92.4 Usual care= 92.8 Education (years): Augmented care= 11.5 ± 2.2; Usual care=11.2 ± 2.8 Socio-economic status: Not stated Other health behaviours: Smoking (%) in augmented care= 20.4; usual care= 20.9

Intervention Type of intervention treatment: augmented prenatal care Content of intervention: higher-risk women received individualised care provided by a group of highly experienced and trained nurses at a specially created Mother and Family Specialty Centre. Women had biweekly antenatal visits throughout pregnancy and weekly after 36 weeks’ gestation with the same health care practitioner. Women were seen within 5 minutes of her schedule appointment time and had 40 minutes visits with their nurse-clinicians or nurse-practitioners, who performed all routine clinical care. Physicians were on call for prompt treatment of medical conditions when necessary as detailed in the trial operations manual.Immediately before or after each appointment, women joined a 40 minute group session led by trained professionals with extensive community experience to offer education about pregnancy, healthy behaviours and peer social support. It included key topics as smoking cessation,weight gain, vitamin-mineral supplementation and amelioration of psychosocial stress/isolation. Supplemental written and video materials to take home were available.Other features included in the programme: two weekly group sessions (weekly after 36 weeks gestation), regular standing appointments, evening hours where needed, appointment reminders, transportation, and on-site childcare. Type of control treatment: usual prenatal care. Content of control:women received usual care from the county health department or the university’s obstetrics department. Women received care by multiple practitioners with monthly appointments until 28 weeks, bimonthly from 28–36 weeks, and weekly after 36 weeks. Women received focused general maternity care with variable levels of informing mothers-to-be about individual risks and how to change.

Outcomes Outcomes considered in the review and reported in or extracted from the study: 5-minute Apgar score below or equal to 7 Admission to special care nursery/NICU Caesarean birth Low birthweight (<2500 g) Preterm birth (< 37 weeks) Overall fetal loss and neonatal death

Notes There was a 7.9% refusal rate (56/712). Experimental and control groups were almost identical in demographic and maternal risk characteristics. But more than 90% of eligible women were not currently married. More than half of participants (58%) were multiparous.

MacVicar 1993

Methods Study design: RCT (Zelen method) Primary aim: to compare outcomes of midwifery-led antenatal and intrapartum care and consultant-led care. Intervention delivery: midwives. Baseline measurements: age, height, gravidity, parity, smoking. Power calculation: initially it was felt that 1000 women in each group would be feasible and would have had adequate power to detect significant changes in outcome measures (such as induction rates or the incidence of perineal tears) whose levels were around 15 to 20%. But the study size had low power (around 50%) to detect even a doubling of the perinatal mortality rate. Over 5000 controls would have been required to show a doubling of the perinatal mortality rate from 5 per 1000 as statistically significant. ITT: Yes. Definition of PTB: birth before 37 weeks’ gestational age. Duration of study: 1989-1991.

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MacVicar 1993 (continued)

Methods Study design: RCT (Zelen method) Primary aim: to compare outcomes of midwifery-led antenatal and intrapartum care and consultant-led care. Intervention delivery: midwives. Baseline measurements: age, height, gravidity, parity, smoking. Power calculation: initially it was felt that 1000 women in each group would be feasible and would have had adequate power to detect significant changes in outcome measures (such as induction rates or the incidence of perineal tears) whose levels were around 15 to 20%. But the study size had low power (around 50%) to detect even a doubling of the perinatal mortality rate. Over 5000 controls would have been required to show a doubling of the perinatal mortality rate from 5 per 1000 as statistically significant. ITT: Yes. Definition of PTB: birth before 37 weeks’ gestational age. Duration of study: 1989-1991.

Participants Setting: tertiary hospital and community in Leicester, UK. Inclusion criteria: women at low risk of complications. Exclusion criteria: women who had a previous difficult vaginal delivery or caesarean section, a complex general medical condition, a previous stillbirth or neonatal death, a previous small-for-gestational-age baby, multiple pregnancy, Rhesus antibodies, or a raised level of serum alpha-feto protein. Risk Assessment criteria: Not applicable Total number of participants randomised: 3510; 2304 to team midwifery group and 1206 to standard care (shared care) group. Loss to follow up: Not stated. Mean maternal age at first visit (years): Team midwifery group = 25.3 ± 4.5 Standard care group = 25.4 ± 4.6 Mean gestational age at first visit: Not stated. Gravidy: Primigravida: team group= 832 (36%) ; standard care= 457 (38%) 2+3: team midwifery = 1193 (52%) and standard care= 600 (48%) ≥4: team midwifery= 276 (12%) and standard care= 149 (12%) Parity: Primiparous: team midwifery= 1040 (45%); standard care= 560 (46%) 1+2: team midwifery = 1131 (45%) and standard care = 570 (47%) ≥3: team midwifery= 130 (6%) and standard care= 76 (6%) Multiple pregnancies: Not applicable. Ethnicity: Not stated. Socio-economic status: Not stated. Education: Not stated. Other health behaviours: Smoking (%) : Team midwifery = 554 (26%) Standard care = 326 (29.8%)

Intervention Type of intervention treatment: team midwifery care Content of intervention: A team of two midwifery sisters assisted by eight staff midwives provided hospital- based antenatal, intrapartum and hospital postnatal care only. All the staff were volunteers. Antenatal midwife-led hospital clinic provided scheduled visits at 26, 36 and 41 weeks’ gestation in collaboration with GPs and community midwives. Referrals to obstetrician were done as appropriate but referral to consultant at 41 weeks was mandatory referral to consultant. Postnatal care in community was provided by GPs and community midwives. Type of control treatment: standard care. Content of control: women received shared antenatal care with midwife and GP. Intrapartum care was provided by hospital staff.

Outcomes Outcomes considered in the review and reported in or extracted from the study: 5 min Apgar score Admission to special care nursery/NICU Caesarean birth Fetal loss/neonatal death before 24 weeks and equal to/after 24 weeks Induction of labour Instrumental vaginal birth (forceps/vacuum) Low birthweight (< 2500 g) Overall fetal loss and neonatal death Preterm birth (< 37 weeks) Spontaneous vaginal delivery (as defined by trial authors)

Notes Women were randomised in in favour of midwife-led care in a 2:1 ratio.

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Main 1989

Methods Study design: RCT Primary aim: to evaluate the impact of a preterm labour detection clinic compared to routine antepartum care.Intervention delivery: physicians and nurse specialists. Baseline measurements: maternal age, gravidity, parity, previous late and early abortions, previous PTB births; gestational age at first visit.Power calculation: A priori power calculations suggested that a sample of 200 in each high-risk group would be adequate to demonstrate an improvement of 4 days in gestational age or a 50% overall reduction in PTBs, from 20% to 10% based on a 90% power and an alpha of 0.05. The study had a power or 0.98 to detect a 7-day improvement in mean gestational age between the high-risk groups, and a power of 0.75 to detect a 4-day improvement. The power to detect a 50% reduction in PTB was 0.91.ITT: No.Definition of PTB: birth of less than 37 weeks’ gestation.Duration of study: 1983-1986.

Participants Setting: obstetric clinic of the University of Pennsylvania Hospital, USA. Inclusion criteria: women were eligible to trial entry of they were (a) Black pregnant women at or before 18 weeks’ gestation and (b) considered to be at high risk of PTB. Risk assessment criteria: Women were identified to be at high risk of PTB based on the Creasy Scoring system value of 10 or more. Exclusion criteria: women were excluded if they had a previous difficult vaginal delivery or caesarean section, a complex general medical condition, a previous stillbirth or neonatal death, a previous small-for-gestational-age baby, multiple pregnancy, Rhesus antibodies, or a raised level of serum alpha-feto protein. Total number of participants randomised: 943; 178 high-risk control women and 567 low-risk women to routine antepartum clinic; and 198 high risk women to the preterm labour detection clinic. Loss to follow up: Not clearly stated. Mean age of participants at first visit (years): High-risk controls = 23.9 ± 5.5 Preterm labour detection clinic = 24.1 ± 5.1 Mean gestational age at first visit (weeks): High-risk controls = 12.5 ± 3.7 Preterm labour detection clinic = 12.0 ± 3.3 Gravidity: High-risk controls = 3.7± 1.9 Preterm labour clinic = 3.8 ± 1.9 Parity: High-risk controls =1.4 ± 1.2 Preterm labour clinic=1.6 ± 1.5 Previous PTBs: High-risk controls =38% Preterm labour clinic = 43% Multiple pregnancies: Not stated. Ethnicity: Black Marital status: Not stated. Socio-economic status: Poor, indigent inner city women. Education: Not stated. Other health behaviours: Not stated.

Intervention Type of intervention treatment: preterm labour detection clinic. Content of intervention: high-risk women received antenatal care on a weekly or biweekly basis from 22 weeks' gestation. Cervical assessments were performed by one of three physicians at each visit. A nurse specialist provided education regarding subtle signs of labour and physicians also reinforced these lessons. Type of control treatment: routine antepartum clinic. Content of control: women randomised into two subgroups; the high risk control group (1) with high-risk women who received antepartum care provided by obstetric residents in the routine obstetric clinic with routine prenatal visits; and the low risk control group (2) with women with Creasy score less than 10, who were followed up in the same clinics led by the same obstetric residents.

Outcomes Outcomes considered in the review and reported in or extracted from the study: 5- minute Apgar score below or equal to 5 Admission to special care nursery/NICU Caesarean birth Mean length of neonatal hospital stay (days) Preterm birth (< 37 weeks) Overall fetal loss and neonatal deaths

Notes High-risk women who participated in the Preterm Labour Clinic in earlier pregnancies were uniformly assigned to it in subsequent pregnancy. Elective abortion and transfer of care rates were higher in control group.

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McLachlan 2012

Methods Study design: RCT Primary aim: to evaluate whether caseload midwifery decreases the cesarean section rates compared with standard care. Baseline measurement: maternal age, gestation at booking, expecting first baby, marriage, education level, family income per year, government benefit main family income, employment, smoking, born in Australia, English as first language and intention to breastfeed. Power calculation: initially it was hypothesised that 1004 women were required in each trial arm to detect a decrease in the caesarean rate from 19% to 14% with 80% power and 95% confidence; and allowing for 10% loss to follow up. But given the rising caesarean rate, the sample size was increased to 1145 women in each arm to detect a 5% difference in the risk of caesarean birth from 25% to 20%, with 80% power and 95% confidence, assuming 1% loss to follow-up. ITT: Yes. Definition of PTB: birth of < 37 weeks’ gestation. Duration of study: 2007-2010

Participants Setting: tertiary care Royal Women’s Hospital (RWH), Melbourne,Australia. Inclusion criteria: women were eligible to trial entry if they were (a) low-risk pregnant women; (b) less than 24 completed weeks’ gestation;(c) had a singleton pregnancy; (c) considered to be at low obstetric risk at recruitment. Risk assessment criteria: Not applicable. Exclusion criteria: women with complicated medical and/or obstetric history including: previous caesarean section, 3 or more consecutive miscarriages, previous fetal death in utero, previous stillbirth or neonatal death, previous preterm birth (< 32 weeks), previous midtrimester loss/cervical incompetence/cone biopsy/known uterine anomaly, previous early onset of pre-eclampsia (< 32 weeks’ gestation), or rhesus iso- immunisation; complications during the current pregnancy (i.e multiple pregnancy or fetal abnormality); medical conditions (such as essential hypertension, cardiac disease, pre-existing diabetes, previous gestational diabetes, renal disease, severe asthma, epilepsy, substance misuse, significant psychiatric disorders and obesity (BMI > 35) or relevantly underweight (BMI < 17)). Total number of participants randomised: 2314; 1156 to caseload care and 1158 to standard care. Loss to follow up: caseload care = 6 an standard care = 1 Mean age of participants at first visit (years): caseload care = 31.2 ± 4.7 an standard care = 31.3 ± 4.7 Mean gestational age at first visit (weeks): caseload care = 16.3 ± 2.8 and standard care = 16.3 ± 2.9 Gravidity (%) First pregnancy: caseload care = 804 (70%) and standard care = 806 (69.7%) Parity: Not stated Multiple pregnancies: Not stated. Previous PTB: Not stated. Ethnicity: Not stated Marital status (%): Married/living with partner: caseload care = 95.2%; standard care =94.3% Socio-economic status: Total family income/year (AUD): <$33,800: caseload care = 123 (10.8%); standard care = 137 (12.1%) $33,801–51,999: caseload care= 201 (17.6%); standard care= 170 (15%) $52,000–72,799: caseload care = 218 (19.1%); standard care = 238 (21%) $–103,999: caseload care =311 (27.2%); standard = 298 (26.3%) $104,000 or more: caseload = 289 (25.3%); standard = 291 (25.7%) Employed (part-time or full-time): caseload = 74.1%; standard = 72.6% Education: Completed degree/diploma: caseload care =77.5% ;standard care = 74% Completed secondary school: caseload care = 16.5%; standard care = 18.7% Did not complete secondary school: caseload =6%; standard =7.3% Other health behaviours. Smoking: caseload = 3.9%; standard = 3.2%

Intervention Type of intervention treatment: caseload midwifery care Content of intervention: women received the majority of the care from a ‘primary’ caseload midwife at the hospital. The primary midwife worked in collaboration with the obstetric team and other health professionals and continued to provide caseload care if complications arose. Women were seen by an obstetrician at booking, at 36 weeks’ gestation and postdates if necessary, and often had one or two visits with a ‘back-up’ midwife. Intrapartum care was provided in the hospital birthing suite and where possible, by the on call primary midwife. The back-up or primary midwife attended the hospital almost everyday to provide some postnatal care and provided community care following discharge from hospital. Type of control treatment: standard care Content of control: women received midwifery-led care with varying levels of continuity, obstetric resident care and community-based care ‘shared’ between a GP and the hospital, where the GP provided the majority of antenatal care. In the GP and midwife-led models women were seen by an obstetrician at booking, 36 weeks’ gestation and postdates if necessary, with additional referral or consultation if required. In all standard care options, intrapartum and postnatal care were provided by whichever doctors and midwives were rostered for duty when women came into the hospital.

Outcomes Outcomes considered in the review and reported in or extracted from the study: 5-minute Apgar score below or equal to 7 Admission to special care nursery/NICU Caesarean birth Fetal loss/neonatal death before 24 weeks Induction of labour

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McLachlan 2012 (continued)

Outcomes Instrumental vaginal birth (forceps/vacuum) Low birthweight (< 2500 g) Overall fetal loss and neonatal death Preterm birth (< 37 weeks) Spontaneous vaginal birth (as defined by trial authors)

Notes During the RCT, there were 7.5 (at starting point) to 12 full-time equivalent midwives working in caseload care, equating to 10-14 midwives. Approximately 70% of women in each arm were primiparous and around 90% of had a known carer in labour.

Rowley 1995

Methods Study design: RCT Primary aim: to compare continuity of care from a midwife team with routine care from a variety of doctors and midwives. Intervention delivery: Midwives. Baseline measurements: maternal age, ethnicity, previous obstetric history, employment, marital status, smoking and BMI, blood pressure and haemoglobin levels. Power calculation: The sample size needed to be at least 360 in each group to have adequate power to detect clinically important differences in obstetric interventions. ITT: Yes. Definition of PTB: birth before 37 weeks’s gestation. Duration of study: 1991-1992.

Participants Setting: John Hunter hospital, Newcastle, NSW, Australia. Inclusion criteria: women who booked for delivery at hospital at low and high risk of complications. Exclusion criteria: women who chose to have shared antenatal care with their GP or had a substance misuse problem. Risk assessment criteria: Not stated. Total number of participants randomised: 814; 405 to team care and 409 to standard care (shared care). Loss to follow up: Not stated. Mean age of participants (years): team care= 26.5; standard care= 26.3 Mean gestational age at fist visit: Not stated. Gravidity: Primipara women team care= 194; standard care= 202 Multipara women: team care=211; standard care=207 Parity, previous PTB, multiple pregnancies: Similar obstetric history. Ethnicity: Most participants were white. Marital status: More than half of women in both groups were married. Socio-economic status: About 20% of women in both groups were employed in trade or skilled labour occupations. Education: Not stated. Other health behaviours: Smoking: More than half were non-smokers.

Intervention Type of intervention treatment: midwifery team care Content of intervention: women received antenatal, intrapartum and hospital care in the hospital and provided by a team of six experienced and newly graduated midwives. Women at low risk saw the obstetrician at 12-16, 36, 41 weeks and additional consultations were scheduled as required. Women at high risk were seen by had an obstetrician at a frequency set on according to their individual care needs. Type of control treatment: standard care (shared care) Content of control: women received antenatal care from hospital physicians and intrapartum and postnatal care from midwives and doctors working in the delivery suite, and the postnatal ward. Women usually saw a doctor at each visit. Control-group midwives were also a mix of newly qualified and experienced midwives.

Outcomes Outcomes considered in the review and reported in or extracted from the study: 5-minute Apgar score below or equal to 7 Antental hospitalisation Admission to special care nursery/NICU Caesarean birth Fetal loss/neonatal death before 24 weeks Fetal loss/neonatal death equal to/after 24 weeks Induction of labour Instrumental vaginal birth(forceps/vacuum) Low birthweight (< 2500 g) Overall fetal loss and neonatal death Preterm birth (< 37 weeks) Spontaneous vaginal birth (as defined by trial authors)

Notes Around 80% of women randomised to team care did receive it.

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Tracy 2013

Method Study design: RCT Primary aim: to compare the clinical and cost outcomes of caseload midwifery care versus standard maternity care for women of any risk in two maternity sites. Intervention delivery: caseload midwives. Baseline measurements: maternal age, parity, identified risk at onset of labour (medical. obstetric or social risk factors), BMI and the Socio Economic Status Indexes for Areas (SEIFA), a product that ranks areas in Australia based on relative socio-economic advantage and disadvantage. Power calculation: A total of 750 women for whom data could be analysed were needed in each group to detect a reduction of caesarean section from 29.4% to 22.9% with a 80% power and a type 1 error of 5%. With an assumption of 30% withdrawals or protocol violations, the study aimed to recruit 1950 women; providing adequate power to examine other outcomes such as a reduction in instrumental birth from 11.% to 6.8% and admission of neonates to NICU or special care nursery from 9.9% to 5.8%. ITT: Yes. Definition PTB: gestational age <37 weeks. Duration of study: 2008-2011

Participants Settings: two Australian integrated maternity centres part of two tertiary hospitals, The Royal Hospital for Women in Randwick, New South Wales (site 1); and the Mater Mother’s Hospital in Brisbane, Queensland (site 2) Inclusion criteria: women were eligible if they were less than 24 completed weeks pregnant at the booking appointment and aged 18 years and older. Risk assessment criteria: Not applicable. Exclusion criteria: women were excluded if they had a multiple pregnancy, had already planned to have an elective caesarean birth, or were planning to book with another care provider (i.e a GP, a private obstetrician or a caseload midwife). Total number of participants randomised: 1748; 871 to caseload care and 877 to standard care. Loss to follow up: 17 to caseload care and 3 to standard care. Mean age of participants at booking (years): caseload care = 31.7 ± 4.8 and standard care = 31.5 ± 5.0 Mean gestational age at booking: Not stated. Gravidity: Not stated. Multiple pregnancies: Not stated. Previous PTB and other medical /obstetric risk factors: caseload care = 512 (59%) and standard care = 530 (60%) Ethnicity: Not stated. Parity: Nulliparous: caseload care = 619 (71%) and standard care = 605 (69%) 1: caseload care = 179 (21%) and standard care = 206 (23%) 2: caseload care = 52 (6%) and standard care = 50 (6%) 3: caseload care = 15 (2%) and standard care = 8 (1%) ≥4: caseload care = 3 (<1%) and standard care = 3 (<1%) Marital status: Not stated. Education: Not stated. Socio-economic status: Median SEIFA index (being 1 the lowest and 10 the highest): Caseload care = 10 (8–10) Standard care = 10 (8–10) Other health behaviours: Not stated

Intervention Type of intervention treatment: caseload midwifery care. Content of intervention: women received individualised antenatal, intrapartum and postnatal care in hospital and in the community from a primary caseload midwife. This named midwife worked within a small group of another three full time midwives known as midwifery group practice. The caseload midwives were backed up when required by other caseload colleagues and by hospital staff during the women’s stay in the postnatal ward. Women received antenatal care tailored to their needs at her home or the community; and combined antenatal and postnatal groups were possible. If required and according to the Australian national midwifery guidelines, women were referred to a senior obstetrician, who was allocated at each midwifery practice for consultation. Urgent care was provided in the hospital by the rostered medical staff. The primary midwife (or a backup midwife if the named midwife was unavailable) was on call for the labour and birth of their assigned women. They also attended the woman in hospital in the first few hours after birth to provide postnatal care and advice until discharge. Women were encouraged to go home early and were visited by their carload midwife in their homes or community for up to 6 weeks, in accordance with each hospital’s guidelines and protocols. Type of control treatment: standard care Content of control: women received standard care at both hospitals which included shared care from hospital midwives and the GP. The GP provided the woman’s antenatal care, usually closer to her home than the hospital, but the woman was booked for extra antenatal care, labour, birth, and postnatal care at the hospital. Antenatal classes were offered in the hospital or community. Standard hospital care was provided through antenatal clinics, labour wards, and postnatal wards, where care is led by rostered medical and midwifery staff. In the standard care, women did not receive substantial continuity of midwifery care, and could potentially see a different midwife at each visit.

Outcomes Outcomes considered in the review and reported in or extracted from the study: 5-minute Apgar score below or equal to 7 Antenatal hospitalisation 5-minute Apgar score below or equal to 7 Antenatal hospitalisation Admission to special care nursery/NICU Breastfeeding initiation Caesarean birth

�19

Tracy 2013 (continued)

Outcomes Fetal loss/neonatal death before 24 weeks Fetal loss/neonatal death equal to/after 24 weeks Induction of labour Instrumental vaginal birth (forceps/vacuum) Low birthweight (< 2500 g) Overall fetal loss and neonatal death Preterm labour (< 37 weeks) Spontaneous vaginal birth (as defined by trial authors)

Notes At site 1 (where 76% of women were enrolled), 40% of participants had access to caseload midwifery as an option, as did only 18% of women at site 2. Thus, many women having a second or subsequent pregnancy chose caseload midwifery model, leaving a very high percentage of primiparous women to be eligible and randomly assigned without preference (70% of all participating women were primiparous)

Tucker 1996

Method Study design: Multicenter RCT Primary aim: to compare routine antenatal care provided by GPs and midwives with shared care led by obstetricians in terms of health service use,indicators of quality of care and women’s satisfaction. Intervention delivery: GPs and community midwives. Baseline measurements: maternal age, height, parity, gravity, gestational age at first visit, previous miscarriages or abortions, smoking, partner’ relationship and partner’s occupational status. Power calculation: based on a 90% power at a significance level of 0.05, there was an estimated sample size of 1640 participants to be recruited to detect a significant differences between incidences of transient hypertension of 6% at GP clinics versus 12% in hospital clinics and differences of 60% versus 70% between two groups reporting satisfaction with the care received. However, it was recognised that it would not be large enough to detect differences between the groups in rare events (i.e maternal and perinatal mortality in low risk women) ITT: Yes. Definition of PTB: birth of less than 37 weeks’ gestation. Duration of study: 1993-1994

Participants Setting: 51 general practices linked to 9 rural or urban hospitals throughout Scotland, UK. Inclusion criteria: women who presented to participating general practices were eligible for trial entry if they were at low risk of antenatal complications and were less than 18 weeks’ gestation by the first visit. Exclusion criteria: women were excluded if (1) they were considered to be at high risk of antenatal complications according to 18 characteristics of previous obstetric history, current pregnancy conditions or serious medical conditions; (b) if by the time of booking were more than 18 weeks’ gestation or had seen an obstetrician before the research midwife and (c) if had had a previous CS. Risk assessment criteria: Not applicable. Total number of participants randomised: 1765; 878 to GP and midwife care and 887 to obstetrician led (shared care). Loss to follow up: GP and midwife care =44 and shared care = 47 Mean age of participants (years): GP and midwife care = 25.8 (25.5 to 26.1) Shared care = 25.6 (25.3 to 25.9) Mean gestational age at first visit (years): GP and midwife care = 12.3 ± 0.2 Shared care = 12.2 ± 0.2 Gravidity: Not done Parity: Not done: Previous PTBs:Not applicable Multiple pregnancies: Not applicable Ethnicity: Not stated. Marital status: Married: GP and midwife care =543 (6%) ;shared care = 521 (63%) Stable: GP and midwife care = 229 (28%); shared care = 240 (29%) Single: GP and midwife care = 45 (5%) ; shared care = 60 (7%) Separated/divorced: GP/midwife care=10 (1%); shared care =11(1%) Socio-economic status: Not stated. Education: Not stated. Other health behaviours. Smoking (%): GP and midwife care = 266 (32%) Shared care = 245 (29%)

Intervention Type of intervention treatment: GP and midwife care. Content of intervention: women received antenatal care delivered entirely by a team of 224 GPs and 45 midwives in the community according to detailed care plans and protocols for managing complications, the “Grampian integrated antenatal care schedule”. Women had routine investigations, including scans, undertaken in primary care, but obstetricians remained responsible for recall of women with identified risk by serum screening. Intrapartum and postnatal care was provided in the hospitals as agreed by hospital participating consultants. Type of control treatment: obstetrician led shared care. Content of control: women received standard shared care between midwives and obstetricians in the participating hospitals.

�20

Tucker 1996 (continued)

Outcomes Outcomes considered in the review and reported in or extracted from the study: Breastfeeding initiation Caesarean birth Fetal loss/neonatal death before 24 weeks Induction of labour Instrumental vaginal birth(forceps/vacuum) Preterm birth (< 37 weeks) Spontaneous vaginal birth (as defined by trial authors)

Notes Similar baseline characteristics in both groups. Compared to women in the shared care group, more women in the GP and midwife care group were referred to hospital staff or changed from their predetermined style of care throughout the antenatal period. Obstetricians provided care in approximately 6% and 28% of all antenatal visits in the experimental and the standard shared care group respectively.

Turnbull 1996

Method Study design: RCT Primary aim: to compare midwife-managed care with shared care in terms of clinical efficacy and maternal satisfaction with care. Intervention delivery: midwives. Baseline measurements: maternal age, parity, smoking, marital status and type of neighbourhood. Power calculation: On one hand, it was estimated that a sample size of 1400 women would have adequate power to detect a significant difference in some outcomes measures ( i.e induction of labour, episiotomy, and satisfaction). At the 5% level, this sample size had 80% power to detect a difference of about 7% between the groups (i.e 30% vs 23% or 75 vs 82%) . On the other hand, a sample of 600 per group gives almost 99% power to detect a difference of 0.2 ± 0.8 units between the mean satisfaction scores of experimental and control groups. ITT: Yes. Definition of PTB: undefined. Duration of study: 1993-1994.

Participants Risk assessment criteria: Not applicable. Total number of participants randomised: 1299; 648 to caseload care and 651 to standard care (shared care). Loss to follow up: caseload care = 5 and standard care =16. Mean maternal age of participants (years): Caseload care = 25.5 ± 5.0 Standard care = 25.8 ± 50 Mean gestational age at first visit: Not stated. Gravidity: Not stated. Parity: Primiparous: caseload care =340 (53.5%); standard care = 352 (54.7%) Multiparous: caseload care = 295 (46.5%); standard care = 291 (45.3%) Multiple pregnancies: Not stated. Previous PTBs: Not applicable. Ethnicity: Not stated. Marital status - Married participants: Caseload care =54.8% Standard care =53.6% Socio-economic status: Type of neighbourhood: 1 (most affluent): caseload care =16 (2.5%); standard care = 19 (3.0%) 2: caseload care =60 (9.5%); standard care = 66 (10.3%) 3: caseload care = 54 (8.5%); standard care = 48 (7.5%) 4: caseload care = 43 (6.8%); standard care = 57 (8.9%) 5: caseload care = 73 (11.6%); standard care = 80 (12.5%) 6: caseload care = 127 (20.1%); standard care = 120 (18.8%) 7: (least affluent): caseload care =259 (41.0%); standard care =248 (38.9%) Health behaviours: Not stated

Intervention Type of intervention treatment: caseload midwifery care Content of intervention: women received caseload midwifery care provided by 20 midwives who voluntary joined a midwifery delivery unit (MDU). Each woman was assigned a named midwife whom she met at her first booking visit and who was aimed to provide the majority of care. Three associate midwives provided the care and when named midwife was not available. Antenatal care was provided at home, community-based clinics or hospital clinics. Intrapartum care was in hospital either in the MDU or main labour suite. Postnatal care was provided in a designed MDU ward and community. Women were not seen by medical staff neither at booking or throughout pregnancy unless there was a deviation from the normal. Type of control treatment: standard care (shared care) Content of control: women received shared antenatal care from midwives, GPs/family doctors and hospital doctors. All women saw a medical staff at booking. Women received intrapartum care on labour suite by a labour ward midwife and postnatal care on both postnatal ward and community by a community midwife.

�21

Turnbull 1996 (continued)

Outcomes Outcomes considered in the review and reported in or extracted from the study: 5-minute Apgar score below or equal to 7 Admission to special care nursery/NICU Caesarean birth Fetal loss/neonatal death before 24 weeks Fetal loss/neonatal death equal to/after 24 weeks Induction of labour Instrumental vaginal birth(forceps/vacuum) Low birthweight (< 2500 g) Overall fetal loss and neonatal death Preterm birth (< 37 weeks) Spontaneous vaginal birth (as defined by trial authors)

Notes The trial was conducted in an inner-city community, and nearly 75% of women were from very deprived backgrounds. Women in the experimental group saw fewer care providers throughout antenatal, labour and postnatal periods. Greater satisfaction was significantly reported by women in the caseload care group than those receiving shared care.

Waldenström 2001

Method Study design: RCT Primary aim: to evaluate the effect of a team midwife care programme in the standard clinic and hospital settings on satisfaction with antenatal, intrapartum and postpartum care in women in early pregnancy at low risk of complications. Intervention delivery: midwives. Baseline measurements: maternal age, gestation at booking, expecting first baby, marital status, English first language, education, further studies, total family income per year, pension/benefit main family income, private health insurance, smoking prior to pregnancy. Power calculation: based on a group size of 1000 women with a 2-tailed alpha of 0.05 would had a 80% power to detect a clinically significant difference of 20% in the proportion of women satisfied with intrapartum care (66 to 86%) assuming losses to follow up (5% miscarriage, 5% not possible to trace and 25% non responding to follow-up questionnaires) ITT: Yes. Definition of PTB: less than 37 weeks’ gestation Duration of study: 1996-1997.

Participants Setting: Royal Women’s Hospital, Melbourne, Australia. Inclusion criteria: women at low risk of complications. Exclusion criteria: non-English speaking women; women more than 25 weeks’ gestation at booking; women at high risk of complications including previous obstetric complications, preterm delivery, intrauterine growth restriction, pre-eclampsia, previous fetal loss, equal or more than three abortions, infertility > 5 years, significant medical disease, substance misuse. Risk assessment criteria: Not applicable. Total number of participants randomised: 1000; 495 to team-midwife care and 505 to standard care (mixture of different models of care) Loss to follow up: team care = 11; standard care =9 Mean age of participants at first clinic (years): team care = 27.9 ± 5.2 and standard care = 27.9 ± 5.2 Mean gestational age at first clinic (weeks): team care = 12.1 ± 4.2 and standard care = 12.4 ± 4.3 Gravidity: Expecting first baby: team care = 292 (59.1%); standard care =306 (60.7%) Parity: Not stated. Multiple pregnancies (twins): team care = 2; standard care =4 Previous PTB: Not applicable Ethnicity: Not stated. Marital status: Married/living with partner: team care= 89.4%; standard care= 88.8% Single: team care= 10.6%; standard care= 11.2% Marital status: Married/living with partner: team care= 89.4%; standard care= 88.8% Single: team care= 10.6%; standard care= 11.2% Socio-economic status. Total family income per year: $20000 or less: team care = 158 (34.4%); standard care = 149(31.4%) $20000 to $30000: team care = 106(23.1%); standard care = 130 (27.4%) $30000 to $40000: team care = 84 (18.3%); standard care = 74 (15.6%) More than $40000: team care = 111 (24.2%); standard care =121 (25.5%) Education:Secondary school to Year 12: team care=291 (58.8%); standard care=298 (59.5%) Secondary school not completed: team care= 194 (39.2%); standard care= 194 (38.7) Primary school only: team care = 7 (1.4%); standard care = 5 (1.0%) Did not attend school: team care = 3 (0.6%); standard care = 4 (0.8%) Degree: team care = 91 (18.6%); standard care = 108 (21.8%) Diploma: team care = 96 (19.7%); standard care = 80 (16.1%) Other health behaviours. Smoking: team care = 194 (39.3%); standard care =179 (35.7%)

�22

Waldenström 2001 (continued)

Intervention Type of intervention treatment: team midwifery care. Content of intervention: women were randomised to a team-midwife care by a team of 8 midwives who provided hospital-based antenatal, intrapartum (birth centre or delivery suite) and some postnatal care in partnership with medical staff. Type of control treatment: standard care Content of control: women were randomised to standard care which included a combination of diverse options of care being provided mainly by doctors; care mostly by midwives in collaboration with doctors (midwives clinics and birth centres); or shared care between hospital doctors and GPs.

Outcomes Outcomes considered in the review and reported in or extracted from the study: 5-minute Apgar score below or equal to 7 Admission to special care nursery/NICU Antenatal hospitalisation Caesarean birth Fetal loss/neonatal death before 24 weeks Fetal loss/neonatal death equal to/after 24 weeks Induction of labour Instrumental vaginal birth (forceps/vacuum) Mean length of neonatal hospital stay (days) Overall fetal loss and neonatal death Preterm birth (< 37 weeks) Spontaneous vaginal birth (as defined by trial authors)

Notes The midwife attending labour was previously met by 65% and 9% of experimental and control group participants respectively.

Appendix 4: Reported outcomes of interest in included studies

�23

Reported outcomes of interest

ID

Primary outcomes Secondary outcomes

Begley 2011 ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓

Biro 2000 ✗ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓ ✓ ✓ ✓ ✓


✗ ✗ ✗ ✗ ✗ ✓ ✗ ✗ ✓ ✗ ✗ ✗ ✗ ✗

Goldenberg 1990

✗ ✗ ✗ ✗ ✗ ✓ ✗ ✗ ✓ ✓ ✗ ✗ ✗ ✓

Hobel 1994 ✗ ✗ ✗ ✗ ✗ ✓ ✗ ✗ ✓ ✗ ✗ ✗ ✗ ✗

Iams 1989 ✗ ✗ ✗ ✗ ✗ ✓ ✗ ✗ ✗ ✗ ✗ ✗ ✗ ✗

Klerman 2001 ✗ ✗ ✓ ✗ ✗ ✓ ✗ ✓ ✓ ✓ ✗ ✗ ✗ ✓

MacVicar 1993 ✗ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓

Main 1989 ✗ ✗ ✓ ✗ ✗ ✓ ✗ ✓ ✗ ✓ ✗ ✗ ✓ ✓

McLachlan 2012

✗ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓

Rowley 1995 ✓ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓

Tracy 2013 ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓

Tucker 1996 ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✗ ✗ ✓ ✗ ✗ ✗

Turnbull 1996 ✗ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓

Waldenström 2001

✓ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓ ✓ ✓ ✓ ✓

Ant

enat

al h

ospi

talis

atio

n

Cae

sare

an b

irth

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rum

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l vag

inal

del

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y (f

orce

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acuu

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Spon

tane

ous v

agin

al d

eliv

ery

(def

ined

by

trial

aut

hors

)

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erm

birt

h (<

37 w

eeks

)

5-m

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pgar

scor

e ≤

7

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ctio

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are

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NIC

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<250

0g)

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al to

/afte

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Mea

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(day

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Outcome of interest reported Outcome of interest not reported

Reported outcomes of interest

ID

Primary outcomes Secondary outcomes

Antenatal hospitalisation

Breastfeeding initiation

Caesarean birth

Induction of labour

Instrumental vaginal delivery (forceps/vacuum)

Preterm birth (<37 weeks)

Spontaneous vaginal delivery (defined by trial authors)

5-min Apgar score ≤ 7

Low birthweight (<2500g)

Admission to special care unit/NICU

Fetal loss/ neonatal death before 24 weeks

Fetal loss/ neonatal death equal to/after 24 weeks

Mean length of neonatal hospital stay (days)

Overall fetal loss and neonatal death

Begley 2011 ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓

Biro 2000 ✗ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓ ✓ ✓ ✓ ✓Collaborative Group 1993

✗ ✗ ✗ ✗ ✗ ✓ ✗ ✗ ✓ ✗ ✗ ✗ ✗ ✗

Goldenberg 1990

✗ ✗ ✗ ✗ ✗ ✓ ✗ ✗ ✓ ✓ ✗ ✗ ✗ ✓

Hobel 1994 ✗ ✗ ✗ ✗ ✗ ✓ ✗ ✗ ✓ ✗ ✗ ✗ ✗ ✗

Iams 1989 ✗ ✗ ✗ ✗ ✗ ✓ ✗ ✗ ✗ ✗ ✗ ✗ ✗ ✗

Klerman 2001 ✗ ✗ ✓ ✗ ✗ ✓ ✗ ✓ ✓ ✓ ✗ ✗ ✗ ✓

MacVicar 1993 ✗ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓

Main 1989 ✗ ✗ ✓ ✗ ✗ ✓ ✗ ✓ ✗ ✓ ✗ ✗ ✓ ✓

McLachlan 2012

✗ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓

Rowley 1995 ✓ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓

Tracy 2013 ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓

Tucker 1996 ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✗ ✗ ✓ ✗ ✗ ✗

Turnbull 1996 ✗ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓

Waldenström 2001

✓ ✗ ✓ ✓ ✓ ✓ ✓ ✓ ✗ ✓ ✓ ✓ ✓ ✓

!!

✓

Ant

enat

al h

ospi

talis

atio

n

Cae

sare

an b

irth

Inst

rum

enta

l vag

inal

del

iver

y (f

orce

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m)

Spon

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ous v

agin

al d

eliv

ery

(def

ined

by

trial

aut

hors

)

Pret

erm

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h (<

37 w

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)

5-m

in A

pgar

scor

e ≤

7

Indu

ctio

n of

labo

ur

Bre

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g in

itiat

ion

Feta

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bef

ore

24 w

eeks

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issi

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ial c

are

unit/

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Low

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<250

0g)

Feta

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/afte

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Mea

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(day

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Ove

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!!

✗

Ant

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irth

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orce

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Spon

tane

ous

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nal d

eliv

ery

(def

ined

by

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aut

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)

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37 w

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)

5-m

in A

pgar

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re ≤

7

Indu

ctio

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itiat

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bef

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24 w

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car

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it/N

ICU

Low

birt

hwei

ght (

<250

0g)

Feta

l los

s/ n

eona

tal d

eath

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al to

/afte

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wee

ks

Mea

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Appendix 5: Characteristics of excluded studies

�24

Beazley 2001

Beazley D, Mercer B, Meyer, et al. The Memphis preterm birth project: prediction and prevention of preterm birth in extremely high risk women [abstract]. Am J Obstet Gynecol 2001; 6: S86.

This randomised prospective trial compared weekly contact with nurse versus routine care for women at high risk of PTB. Differences in PTB outcomes was not significant (43% vs 41%). This study was published in abstract form only and it was not clearly stated how many women were in control and intervention groups.

Conover 2001

Conover CJ, Rankin PJ, Sloan, FA. Effects of Tennessee Medicaid managed care on obstetrical care and birth outcomes. J Health Polit Policy Law 2001; 6:1291-1324.

This study compares two neighbouring states to determine whether Medicaid managed care provided to high risk pregnant women affected antenatal care, care patterns at labour and delivery, and birth outcomes. This before and after study had less than two intervention sites and two control sites.

Harvey 1996

Harvey S, Jarrell, J, Brant R. et al. A randomised, controlled trial of nurse-midwifery care. Birth 1996; 1:128–135.

This study compared two models of care for all low-risk women: nurse-midwifery care and standard care from either an obstetrician or family physician. Even if preterm labour was stated in antenatal complications, preterm births were not reported.

Homer 2001

*Homer CS, Davis G, Brodie P. et al. Collaboration in maternity care: a randomised controlled trial comparing community-based continuity of care with standard hospital care. BJOG 2001; 2:16–22. Homer CS, Davis GK, Brodie PM. What do women feel about community-based antenatal care? Aust N Z J Public Health 2000; 2:590–595. Homer CS, Davis GK, Cooke M, et al. Women’s experiences of continuity of midwifery care in a randomised controlled trial in Australia. Midwifery 2002; 2:102–112. Homer CS, Matha, DV, Jordan LG. et al. Community-based continuity of midwifery care versus standard hospital care: a cost analysis. Aust Health Rev 2001; 1:85–93.

This Australian RCT compares two models of childbearing care: a new community- based model of continuity of care provided by both midwives and obstetricians or standard hospital-based care. Antenatal complications reported in the study included threatened preterm labour, but PTB were not reported in outcomes.

Konte 1988

Konte JM, Creasy RK, Laros RK. Jr. California North Coast Preterm Birth Prevention project. Obstet Gynecol 1988; 5:727-30.

This interrupted time study evaluated the effectiveness of a PTB prevention programme provided by project nurses in a rural population by comparing pre- intervention deliveries with births of women during the intervention period.

North stafford 2000

North Staffordshire Changing Childbirth Research Team. A randomised study of midwifery caseload care and traditional ’shared-care’. Midwifery 2000; 4:295– 302.

This cluster randomised trial evaluated caseload midwifery care in comparison to traditional 'shared care’ for all pregnant women. Gestation at birth in neonatal outcomes was reporting in the non-standard manner ( including births defined between 34 and 40 weeks) and total number of PTBs was not obtainable.

Mueller - Eubatch 1989

Mueller-Heubach E. Results of a three-year prospective controlled randomised trial of preterm birth prevention at the University of Pittsburgh. Advances in the Prevention of Low Birthweight: an International Symposium;May 8-11; Cape Cod, Massachusetts, USA. 1988; 61–66. Mueller-Heubach E, Guzick DS. Evaluation of risk scoring in a preterm birth prevention study of indigent patients. Am J Obstet Gynecol 1989; 4:829-837 *Mueller-Heubach E, Reddick D, Barnett B, Bente R. Preterm birth prevention: evaluation of a prospective controlled randomised trial. Am J Obstet Gynecol 1989; 5:1172–1178.

This study is a prospective RCT to evaluate a PTB prevention programme for high risk women involving weekly cervical examinations and instruction regarding subtle symptoms and signs of preterm labor. No significant difference in PTBs were found between control and intervention groups (20.8% vs. 22.1%). The number of participants randomised to each group was not obtainable and therefore not possible to analyse such data.

Appendix 6: Risk of bias in included studies

�25

Bergley 2011

Risk of bias

Bias Authos’s judgements Support for judgment

Random sequence generation (selection bias)

Low risk “Random integers were obtained using a random number generator available in StatsDirect…”

Allocation concealment (selection bias)

Low risk “… using an independent telephone randomisation service…

Blinding of participants and personnel (performance bias) All outcomes

High risk “…carers were aware that all women in the MLU were included in MidU. Therefore, identification of women randomised to the CLU group was not masked, as blinding participants allocated to control groups when it is impossible to blind those in experimental groups has been criticised…”

Blinding of outcome assessment (detection bias) All outcomes

High risk “Assessors for certain outcomes, such as laboratory tests, were blinded to study group…”

Incomplete outcome data (attrition bias) All outcomes

Low risk Loss to follow-ups = 5 in the MLC groups and loss to follow-up = 3 in the CLC group.

Selective reporting (reporting bias)

Low risk Outcome reporting: all outcomes stated in the methods section were adequately reported or explained in results.

Other bias Low risk No other bias identified.

Biro 2000

Risk of bias



Low risk “Allocations were computer generated…"


Low risk “...the research team member telephoned the medical records staff and asked them to select an envelope with the randomized treatment allocation.’


Unclear risk Insufficient information to permit judgement of “High risk” or “Low risk”




Low risk Loss to follow-up =14 in team care group and loss of follow up =18 in standard care group.


Low risk Outcome reporting: all outcomes stated in the methods section were adequately reported in results.


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Risk of bias



Low risk “A randomisation key with permuted blocks of 8 within centres was computed generated at the University of California at San Franciso and sent to each institution in sequence numbered envelopes, the randomisation ratio being 1:1…”


Unclear risk “sequence numbered envelopes, the randomisation ratio being 1:1…” Randomisation dates were not completely in the same order as the assigned randomisation sequence numbers.


Unclear risk “Inability to blind the staff as to patient randomisation group status”. Information regarding blinding of participants not stated but unlikely.


High risk “The principal investigators at each site reviewed all diagnoses of spontaneous or induced preterm labour and reviewed the birth records of all neonates…”


Unclear “There was data missing in the charts of those admitted for preterm labour at some centres…” But insufficient information of attrition/exclusions provided to permit judgement of “High risk” or “Low risk”



Other bias High risk Contamination of control groups with intervention (same programme-trained staff, prior use of program at some centres).

Goldenberg 1990

Risk of bias



Low risk “Each high risk woman was contacted by the randomisation officer, who described the project…if the woman consented to be enrolled in the project, she was immediately randomised to a treatment or control group…”


Low risk “Each high risk woman was contacted by the randomisation officer, who described the project…if the woman consented to be enrolled in the project, she was immediately randomised to a treatment or control group…”


High risk “Women in the treatment group were identified as project participants in their obstetric records…” No information stated about blinding of personnel but unlikely.


Low risk “…neither the clinicians evaluating the infants nor those abstracting the newborn records were aware of the mothers’ risk status…”


Unclear risk Insufficient information of attrition/exclusions to permit judgement of “High risk” or “Low risk”




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Hobel 1994

Risk of bias



Unclear risk Not applicable - Cluster randomised.“…clinics were randomised with a restricted block (grouped by size and percent black) randomised scheme to identify the clinic as either experimental (five clinics) or control (three clinics)…”


Unclear risk Not applicable - Cluster randomised.


High risk Women were randomised based on which clinic they attended and therefore they were not blinded to receive either experimental or control clinic. Only women randomised to the progestin and placebo groups “were blinded with respect to which of the groups they were assigned. This was also true for staff...”


Unclear risk Randomisation at the clinic level would be likely to reduce bias associated with contamination, but t is not clear whether lack of blinding or incomplete blinding represents a serious source of bias in the study.


Low risk The analysis of the randomised interventions excluded women with who aborted at > 20 weeks' gestation (no number of exclusions reported), pregnancies that resulted in stillbirths (experimental group = 15 and control group = 6) or major congenital anomalies (experimental group = 7; control group = 4), pregnancies after 1986 (experimental group =225; control group = 90),), multiple gestations (experimental group=7; control group = 12; patients lost to follow-up (experimental group =307; control group = 132)



Other bias High risk Contamination of control groups with intervention (same programme-trained staff, prior use of program at some centres).

Iams 1989

Risk of bias



Unclear risk Insufficient information about the sequence generation process to permit judgement of risk of bias.










Unclear risk Outcome reporting: all outcomes stated in the methods section were adequately reported in results.

Other bias Unclear risk Contamination of control groups with intervention (same programme-trained staff, prior use of program at some centres).

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Klerman 2001

Risk of bias



Low risk “… women were randomly assigned to augmented care or usual care…”


Low risk "After written informed consent was obtained, the nurse opened a sealed envelope revealing the woman’s assignment to augmented care or usual care…”


Unclear risk The nurses were aware whether a woman was assigned to the intervention or the control group. No information is provided on blinding of participants in the intervention arm.


Low risk “During the second year, a structured postpartum interview with women in both the augmented care and usual care groups was administered by interviewers blind to the treatment group…”. Postpartum interviews during the first year were not included in the analysis due to inconsistencies in the administration that raised questions about their validity.


Unclear risk Fetal deaths in treatment group= 7 and in control group=5; not included in the analysis. No information provided on loss to follow up.


Low risk Outcomes reporting: all outcomes stated in the methods section were adequately reported in results

Other bias Unclear risk "Many women were not recruited into the study until the middle of their second trimester or later…longer exposure to the intervention possibly could have produced more positive results…”

MacVicar 1993

Risk of bias



Low risk “…by a random sequence…"


Low risk “...sealed envelope, cards could not be read through the envelopes. Each envelope was numbered, and unused envelopes were not reallocated...’


Unclear risk Clinical staff were not aware whether a specific woman was in the control group or was not in the study. No information provided regarding blinding of participants or women in intervention arm.








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Main 1989

Risk of bias



High risk “Assignment of the first 479 women (May 1, 1983 to June 14, 1984) was based on consecutive numbers of a random numbers table. The second sample of 464 women (Jun 15, 1984 to May 30, 1986) groups divided into groups by birthday (even versus odd day of the month)”


High risk “To ensure against unconscious bias, we elected to change to a patient assignment scheme that could be validated independently (maternal day of birth) for the second half of the study…”


Low risk “Neither the physicians or the high risk control patients were informed of their risk status…”. Binding of participants attending the preterm labour detection clinic is unlikely due to the frequency of attendance.


Low risk “…the first consecutive 699 cases were reviewed by one neonatalogist blinded to maternal group assignment…”


High risk There was an approximately 19.2 % missing data for neonatal outcomes and not all infant cases were examined. Insufficient information of attrition/exclusions to permit judgement of “Yes” or “No”.



Other bias Unclear risk Women included in study during more than one pregnancy.

McLachlan 2012

Risk of bias



Low risk “…using stratified permuted blocks of varying size…Randomisation was stratified by parity (first or subsequent birth)…”


Low risk ’Randomisation was undertaken using an interactive voice response system activated by telephone...’


Unclear Insufficient information to permit judgement of “High risk” or “Low risk”


Low risk “Obstetric and medical outcome data (including type of birth) were obtained directly from the electronic obstetric database, blinded to treatment allocation. Data not available this way (e.g. continuity of carer) were manually abstracted (unblinded) from the medical record.”


Low risk Loss to follow-up in caseload care group= 6 and loss of follow-up in standard care group= 1.




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Rowley 1995

Risk of bias



Low risk “Allocation to either team care or routine care was done by computer-generated random assignments…”


Unclear “The women were allocated at random to team care or routine care…”


High risk ...the unblinded nature of the study could have led to differences in practice and measurement of outcomes...’


High risk “...the unblinded nature of the study could have led to differences in practice and measurement of outcomes…"






Tracy 2013

Risk of bias



Low risk “Those who agreed and provided written informed consent were randomly assigned by a telephone-based computer randomisation service…”


Low risk “were randomly assigned by a telephone-based computer randomisation service either to caseload midwifery or to standard maternity care…”


High risk "Because of the nature of the trial, no attempt was made to mask study assignment from the participant or the clinician…”


Low risk “Study assignment was masked from the statistician who analysed the data.”


Low risk Outcome data was not available for 31 participants in the caseload care (17 lost to follow-up - could not be contacted-, 3 withdrew consent and 11 pregnancies lost before 20 weeks) and 50 participants in the standard care (24 lost to follow-up -could not be contacted-, 12 withdrew consent, 12 pregnancies lost before 20 weeks and 2 terminations of pregnancy (lethal congenital anomaly)).




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Tucker 1996

Risk of bias



Low risk “Randomisation was by telephone to a secretary… restricted randomisation was used to maintain equal numbers in both arms of the trial. Permuted block size of 14-20 was used to prevent anticipation of the next trial allocation. Randomisation was not stratified…


Low risk “Randomisation was by telephone to a secretary who held the trial allocations in a series of opaque non-resealable envelopes…”






Low risk Incomplete medical records for 91 participants (due to loss of shared care cards and women moving away): 44 in the GP and midwife care group and 47 in the shared care group.




Turnbull 1996

Risk of bias



Low risk “ A restricted randomisation scheme (random permutated blocks of ten) by random number tables was prepared for each clinic by a clerical officer who was not involved in determining eligibility, administering care, or assessing outcome”.


Low risk “The research team telephoned a clerical officer in a separate office for care allocation for each woman”


Unclear risk “Clinical staff were not aware whether a specific woman was in the control or was not in the study.” No information provided regarding blinding of participants.


Unclear risk “Clinical data were gathered through a retrospective review of records by the research team who were not involved in providing care”


Low risk Loss of follow-ups in team care group =5 and loss of follow-ups in shared care group =16




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Waldenström 2001

Risk of bias





Low risk “The research midwife rang a clerk at the hospital’s information desk who opened an opaque, numbered envelope that contained information about the allocated group…”






Low risk Loss of follow-ups in team care group =11; and loss of follow-ups in standard care group =16.




Appendix 7: Approximate analysis of the cluster randomised trial

In the cluster trial, participants were randomised together as a group or cluster to the experimental or control clinics. Thus, the unit of analysis was different from the unit of allocation of participants. Since women within the cluster tended to respond in a nearly identical manner, their data could no longer be assumed to be independent of one another. Thus, adjustments needed to be made before the data could be included in the meta-analysis in order to receive the appropriate weight and avoid potential unit of analysis errors and small p values resulting in false positive results of intervention effects.

An approximately correct analysis was performed. The idea was to reduce the size of each trial to its effective sample size. The effective sample size of each intervention group in the cluster study was its original sample size divided by a quantity called the design effect. This design effect was 1+(M–1) x ICC, where M was the average cluster size and ICC was the intracluster correlation coefficient that estimated the relative variability within and between clusters. Then, a common design effect was assumed across experimental and control groups. For dichotomous data, both the number of events and the number of participants were divided by the same design effect. The results were rounded to whole numbers for entry into RevMan. Once in RevMan, effect estimates and their standard errors from correct analysis were meta-analysed using the generic inverse-variance method. Details of approximate analyses and effective sample sizes for the PTB and low birthweight outcomes are shown below:

5.1 Effective sample sizes for PTB outcome

• The cluster trial randomised five specialised prenatal clinics with 1774 participants into the experimental group; and three prenatal clinics with 880 participants into the control group. The numbers of PTB among the women, ignoring the clustering, were: Experimental: 131/1174 ; Control: 80/880

• An ICC of 0·002 with 95% CI 0·0005 to 0·0041 was obtained from a reliable external source. The average cluster size in the trial was (1774 + 880)/(5+3) = 331·75. Then, the design effect for the trial as a whole was 1 + (M– 1)×ICC = 1+(331·75–1)×0.002=1·6615. The effective sample size in the experimental group was 1174/1·6615 = 1067·7 and for the control group was 880/1·6615 = 529·6.

• Design effects were also applied to the numbers of events (PTBs) resulting in 131/ 1·6615 in the experimental group and 80/1·6615 in the control group; producing the following results: Experimental: 78·8/1·6615 ; Control: 48·1/1·6615

• Once the trial was reduced to its effective sample size, the data was entered into RevMan as: Experimental: 80 /1068 ; Control: 48/530.

5.2 Effective sample sizes for low birthweight outcome

• Following the same process, effective sample sizes for low birthweight outcome were calculated. The numbers of low birthweight babies among participants, ignoring the clustering, were: Experimental: 103/1174 ; Control: 56/880

• An ICC of 0·0003 with 95% CI −0·0006 to 0·0016 was obtained from the same external source. The average cluster size in the trial was the same: 331·75. The design effect for the trial as a whole was then 1+ (331·75– 1)×0.0003 = 1·0992. The effective sample size in the experimental group was 1174/1.0992 = 1068.04 and in the control group was 880/1·0992 = 800·6. Design effects were also applied to the numbers of events resulting in 93·7 in the experimental group and 50·9 in the control group.

• Once the trial was reduced to its effective sample size, the data was entered into RevMan as: Experimental: 94 /1068; Control: 51/801.

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Appendix 8: Risk assessment criteria used in included studies

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Creasy Scoring System

Four studies18,19,21,24 used the Creasy Scoring system of risk factors to predict PTB, computed by addition of the number of points given to more than 30 items divided into four categories on a screening questionnaire (socio-economic, prior medical history, daily habits and current pregnancy problems). Women with a Creasy scoring of 10 or more were generally considered at high risk.

Risk scoring tool derived from the same study population

The cluster trial20 used a risk assessment tool derived from the same population before the initiation of the study and women were classified at at high risk of PTB if they had one or more of pre-specified historical and developing risk factors (i. e previous PTB, pre-eclampsia, tobacco or narcotics use, vaginal bleeding or multiple pregnancy)

Other risk assessment scales

The risk assessment scale used in another study22 assigned 10 points to a woman for each factor in a first group: prior PTB, pre-pregnancy weight ≤50 kg, no automobile for transportation; and 5 points for each in a second group: previous full-term low-birthweight infant, smoking at the time of pregnancy; body mass index (BMI) of less than 19.8 for women who weighed more than 50 kg; and perceived lack of mastery, ascertained by agreement with the statement “There is little that I can do to change many of the important things in my life”. To be considered at high risk of PTB, woman needed to have at least one of the factors in the first group or at least two in the second.

Appendix 9: Alternative antenatal care models vs routine care for all pregnant women: primary and secondary outcomes.

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Fig 9.1 Forest plot comparing antenatal hospitalisation between pregnant women receiving alternative models of antenatal care and those receiving routine care.

Fig 9.2 Forest plot comparing breastfeeding initiation between pregnant women receiving alternative models of antenatal care and those receiving routine care.

Fig 9.3 Forest plot comparing caesarean birth between pregnant women receiving alternative models of antenatal care and those receiving routine care.

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Fig 9.4 Forest plot comparing induction of labour between pregnant women receiving alternative models of antenatal care and those receiving routine care.

Fig 9.5 Forest plot comparing instrumental vaginal delivery (forceps/vacuum) between pregnant women receiving alternative models of antenatal care and those receiving routine care.

Fig 9.6 Forest plot comparing spontaneous vaginal birth (as defined by trial authors) between pregnant women receiving alternative models of antenatal care and those receiving routine care.

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Fig 9.7 Forest plot comparing preterm birth (<37 weeks) between pregnant women receiving alternative models of antenatal care and those receiving routine care - adjusted for cluster design effect (ICC 0·002).

Fig 9.8 Forest plot comparing preterm birth (<37 weeks) between pregnant women receiving alternative models of antenatal care and those receiving routine care - Sensitivity analysis: adjusted for cluster design effect using upper CI (ICC 0·0041)

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Fig 9.10 Forest plot comparing 5-min Apgar score ≤ 7 between infants of pregnant women receiving alternative models of antenatal care and infants of those receiving routine care.

Fig 9.9 Forest plot comparing preterm birth (<37 weeks) between pregnant women receiving alternative models of antenatal care and those receiving routine care - all studies, unadjusted data.

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Fig 9.11 Forest plot comparing admission to special care unit/NICU between infants of women receiving alternative models of antenatal care and infants of those receiving routine care.

Fig 9.12 Forest plot comparing fetal loss/ neonatal death before 24 weeks between pregnant women receiving alternative models of antenatal care and those receiving routine care.

Fig 9.13 Forest plot comparing fetal loss/ neonatal death equal to/after 24 weeks between pregnant women receiving alternative models of antenatal care and those receiving routine care.

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Fig 9. 14 Forest plot comparing low birthweight (<2500g) between infants of women receiving alternative models of antenatal care and infants of those receiving routine care - adjusted for cluster design effect (ICC 0·0003).

Fig 9.15 Forest plot comparing low birthweight (<2500g) between infants of women receiving alternative models of antenatal care and infants of those receiving routine care - Sensitivity analysis: adjusted for cluster design effect using upper CI (ICC 0·0016).

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Fig 9.16 Forest plot comparing low birthweight (<2500g) between infants of pregnant receiving alternative models of antenatal care and infants of those women receiving routine care - all studies, unadjusted data.

Fig 9.17 Forest plot comparing mean length of neonatal hospital stay (days) between infants of women receiving alternative models of antenatal care and infants of those women receiving routine care.

Fig 9.18 Forest plot comparing overall fetal loss and neonatal death between pregnant women receiving alternative models of antenatal care and those receiving routine care.

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Fig 9. 20 Funnel plot comparing preterm birth (<37 weeks) between pregnant women receiving alternative models of antenatal care and those receiving routine care - data adjusted for cluster design effect (ICC 0·002).

Fig 9.19 Funnel plot comparing caesarean birth between pregnant women receiving alternative models of antenatal care and those receiving routine care.

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Fig 9.21 Funnel plot comparing admission to special care unit/NICU between infants of women receiving alternative models of antenatal care and infants of those receiving routine care.

Fig 9.22 Funnel plot comparing overall fetal loss and neonatal death between pregnant women receiving alternative models of antenatal and those receiving routine care.

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Fig 9.23 Forest plot comparing preterm birth (<37 weeks) between pregnant women receiving alternative models of antenatal care and those receiving routine care - Sensitivity analysis: high quality studies at low risk of bias

Appendix 10: Maternal Satisfaction

Women’ experiences of antenatal care

Satisfaction Intervention (n/N)

Control (n/N)

Statistical test 95% CI p value

Biro 2000 RR

Asked whether had any questions (strongly agree)

247/340 (72·6%)

150/287 (52·3%)

1·25 1·15-1·36 <0·001

Found doctors/midwives very rushed at visits (strongly disagree)

99/342 (28·9%)

41/287 (14·3%)

1·51 1·24-1·84 <0·001

Felt worries and concerns were taken seriously by midwives/doctors (strongly agree)

177/341 (51·9%)

79/286 (27·6%)

1·43 1·26-1·62 <0·001

Always kept informed and given answers they could understand (strongly agree)

218/341 (63·9%)

115/286 (40·2%)

1·26 1·15-1·38 <0·001

Felt happy with the physical care received from doctors/midwives (strongly agree)

201 /342 (58·8%)

98/285 (34·4%)

1·25 1·13-1·37 <0·001

Felt happy with the emotional support received from doctors/midwives (strongly agree)

177/342 (51·8%)

80/285 (28·1%)

1·57 1·39-1·78 <0·001

Always given an active say in decisions about care (strongly agree)

165/337 (49·0%)

87/283 (30·7%)

1·37 1·21-1·54 <0·001

195/344 (57%)

100/287 (35%)

1·24 1·13-1·36 <0·001

Klerman 2001

Prenatal care overall (very helpful)

110 (94·0%)

84 (80%)

0·002

Compared with last time, prenatal care overall (better)

49 (74·2%)

18 (30%)

0·001

Average time reported with nurse per visit (about 30 minutes)

73 (63·5%)

50 (49%)

0·001

Same nurse reported as providing care each visit

112 (96·6%)

88 (83·8%)

0·001

Nurse rated as very helpful 107 (93·9%)

82 (78·9%)

0·001

MacVicar 1993 Difference

Very satisfied with antenatal care

52% 44% 8.3% 4.1-12.5 <0·001

MacVicar 1993 OR

Encouraged to ask questions N/A 4·22 2·72-6·55

Given comprehensive answers N/A 3·03 1·33-7·04

Able to discuss fears or anxieties N/A 3·60 2·28-5·69

Given choices and explained to them N/A 4·17 1·93-9·18

& Satisfaction with antenatal care (very good)

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Women’ experiences of antenatal care (continued)

Satisfaction Intervention (n/N)

Control (n/N)

Statistical test 95% CI p value

Tucker 1996

Overall satisfaction: enjoyed care (yes)

460/656 (70%)

411/656 (63%)

0·04

Happy with arrangements of visits (yes)

618/666 (93%)

624/666 (94%)

0·6

Getting on with your own carer (very well)

469/665 (71%)

448/665 (67%)

0·04

Preferred level of continuity of care (same person each visit)

194/665 (29%)

117/665 (18%)

<0·0001

Satisfaction with information acquisition (very satisfied)

203/638 (32%)

198/639 (32%)

0·6

Turnbull 1996

Offered little choice about care (choice) (strongly disagree)

83·8% 52% <0·00001

Getting too little information (strongly disagree)

90% 65% <0·00001

Felt in control of decisions about the care wanted (strongly agree)

87·3% 62·8% <0·00001

Felt staff were interested in herself and not just the pregnancy (strongly agree)

80·2% 56·2% <0·00001

Waldenström 2001 OR

Always informed/explained anything they didn't understand (strongly agree)

48·3% 32·4% 2·17 1·64-2·68 <0·001

Always given an active say in decisions about care (strongly agree)

44·6% 38·7% 1·49 1·13-1·97 0·005

Midwives/Doctors were encouraging/reassuring (strongly agree)

59·5% 38·6% 2·46 1·84-3·29 <0·001

Found midwives/doctors very rushed at check ups (Strongly disagree)

38·3% 14·6% <0·001

Felt happy with physical/emotional aspects of care (strongly agree)

52·9% / 52·5% 35·7% / 31·9% 2·02 / 2·39 1·53-2·68 /1·81-3·16

<0·001

Overall antenatal care was very good (strongly agree)

58·2% 39·7% 2·22 1·66-2·95 < 0·001

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Appendix 11: Economic analysis of preterm birth

Study ID Economic evaluation

Hobel 1994 Ross and colleagues used cost calculations weighted by the actual proportions of term and PTBs to determine prenatal care costs, inpatient preterm labour, delivery and postpartum care, and newborn care associated with the West Los Angeles Preterm Birth Prevention Project. When compared to control clinic high-risk women, experimental clinic high-risk women had a significant average cost savings of $2196 for newborn care, resulting in a net savings of $1768 per high-risk mother–infant pair. The greatest costs were for births prior to 32 weeks’ gestation. The authors concluded that comprehensive prenatal care and patient education programmes might be highly cost-effective for preventing PTBs.

Main 1989 To assess the economic impact of the Preterm Labor Detection Program in Philadelphia, Main and her team estimated inpatient costs from the hospital charges and outpatient costs from an internal study undertaken at the Department of Obstetrics and Gynaecologist, which assumed a cost of $53 for each obstetric clinic visit. Evaluations of inpatient charges disclosed no significant differences due to participation in this programme, but outpatient clinic utilisation and charges increased significantly for the women in the Preterm Labor Clinic ($1125) compared to women in the high-risk control group ($542).

Tracy 2013 The Australian-refined Diagnosis-Related Group (DRG) classification codes (activity-based funding codes) were used to calculate cost outcomes per woman for caseload midwifery and standard maternity care. Total caseload midwifery care costs were significantly lower per woman than the standard maternity care costs (AUS$ 5497·34 and AUS$ 5903·67, respectively), contributing to a significant difference in the overall median cost of birth per woman of AUS$ 566·74 (95% CI 106·17–1027·30; p=0·02). The cost data included a few high-cost outliers >$30,000 as well, which were mainly associated with serious medical and surgical complications or accidental causes.

Tucker 1996 Tucker's team comprehensively calculated the health service costs for antenatal care for low-risk women when provided by standard obstetrician-led shared care or GP/community midwife care, by estimating costs applied to each specific element of her resource use. The cost of GP/midwife care was found to be significantly less than shared care in terms of routine antenatal visits (£87·25 and £91·15, respectively), staff costs at each visit (£127·76 and £131·09, respectively), and non-health service costs incurred by the women and their families (£127·76 and £131·09, respectively). The total cost of antenatal care was £417·28 per woman in the GP/midwife group and £450·19 in the shared care group.

Turnbull 1996 Lastly, Young and colleaguesn used the “individual patient-based costing” approach, based on assumptions about specific numbers of caseloads per midwife, to compare the costs of midwife-managed antenatal care to shared antenatal care. The authors initially used an assumption based on a median caseload of 29 women per midwife and found non-significant cost differences between midwife-managed care and shared-care groups in the antenatal period. A second assumption was based on a caseload of 39 women per midwife and showed a significantly lower cost for antenatal time for the midwife-managed care model compared to the shared-care group (£346 versus £384).

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appendix 1: details of systematic search strategies

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