Foley Bulb

When

Why

How

MODIFIED BISHOP SCORE BEST PPV FOR DELIVERY

• The Modified Bishop score appears to be the best available tool for predicting the likelihood that induction will result in vaginal delivery. This conclusion is based on systematic reviews of controlled studies that found the Bishop score was as, or more, predictive of the outcome of labor induction

• Compared to fFN  • Compared to sonographic measurement of cervical

length

CERVICAL DILATATION IS THE MOST PREDICTIVE VARIABLE IN THE SCORING SYSTEM.

MODIFIED BISHOP SCOREONLY 3 VARIABLES

Positive Predictive Value for Delivery Equals or Exceeds

Original 5 variable Bishop Score

CERVICAL DILATION IS THE STRONGEST PREDICTOR AND

CARRIES DOUBLE WEIGHT

Obstet Gynecol 1982;60:137

DILATION SCORE

0

0 cm

2

1-2 cm

4

3-4 cm

6

>4 cm

CERVICAL LENGTH SCOREBy digital PALPATION

0

3 cm

1

2 cm

2

1 cm

3

0 cm

STATIONSCORE

In relation to spines

0

-3

1

-2

2

-1/O

3

+ 1/+2

Favorable Cervix is score of 6

• Modified Bishop Score of < 5 is associated with an increased risk for a 2 day induction and ~ Doubles the Risk of Cesarean Section

- Most dependent on whether the cervix is dilated

- Also affected by Parity & use of Prostaglandins

Am J Obstet Gynecol 2003 Jun;188(6):1565-9

USE Foley Bulb UNFAVORABLE CERVIX

Consider Foley Bulb as an alternative to Cytotec. A Foley bulb induction has been validated to be as effective as Cytotec regarding successful induction;

Foley has been reported to be associated with less hyperstimulation & less meconium passage vs Cytotec ?safer?

Although RCT’s comparing Foley bulb vs Cervidil are not available;Foley bulb induction has been consistently demonstrated to be as effective as Cytotec. Cytotec has been demonstrated to be more effective @ successful induction than Cervidil.

Foley bulb induction is certainly much less costly than Cervidil in a patient that you may be concerned has “ marginal placental / fetal reserve” and is just as easily removed as Cervidil.

$213 $ for Cervidil

Cochrane Database Syst Rev 2003

Why a Foley Bulb InductionAs Effective as Cytotec and Probably safer • Uterine contractile abnormalities and meconium passage are more

common with misoprostol. Intravaginal misoprostol and transcervical Foley catheter are equivalent for cervical ripening. Obstet Gynecol 2001 Apr;97(4):603-7.

• The shortest mean induction-to-delivery interval was obtained with the Foley vs prostaglandins ( 12.9 hours versus ~ 17 hours ). Induction of labor with a transcervical balloon catheter is effective and safe and can be recommended as the first choice. BJOG. 2008 Oct;115(11):1443-50.

• Intravaginal misoprostol and intracervical Foley catheter are comparable for preinduction cervical ripening. Am J Obstet Gynecol 2003 Oct;189(4):1031-5

• In conclusion, the maternal and perinatal outcomes in this study have shown no difference confirming the efficacy and safety of either Foley catheter induction or misoprostol. J Obstet Gynaecol. 2005 Aug;25(6):565

The Efficacy of a Foley Bulb Induction has been Associated with

How Distended the Bulb is

• Use a 30 ml Foley bulb which will distend well beyond the 30 ml bulb size. 60-80 ml works better than 30 ml

• Distend to a -60 ml minimum -80 ml maximum -50 ml maximum if a VBAC induction

A randomized trial comparing a 30-mL and an 80-mL Foley catheter balloon for

preinduction cervical ripening.Two hundred and three women were included in the

analysis. Ripening of the cervix with the larger balloon volume was associated with a significantly higher rate of post-ripening dilatation of 3 cm or more (76.0% vs 52.4%, P<.001). In primiparous women, the larger balloon volume resulted in a significantly higher rate of deliveries by 24 hours (71.4% vs 49%, P<.05), and a significantly less requirement of augmentation with oxytocin (69.3% vs 90.4%, P<.05). CONCLUSION: Ripening of the unfavorable cervix in primiparous women with a Foley catheter balloon inflated with 80 mL provided effective more dilatation, faster labor, and decreased need for oxytocin than with a balloon inflated with 30 mL of sterile saline.

Am J Obstet Gynecol 2004 Nov;191(5):1632-6.

Labor induction with a Foley balloon inflated to 30 mL compared with 60 mL: a

randomized controlled trial.

• A higher proportion of women randomly assigned to the 60-mL Foley balloon achieved delivery within 12 hours of placement compared with the 30-mL Foley balloon group (26% compared with 14%, P=.04). This difference was more pronounced among nulliparous women. There was no difference in median time interval to delivery or proportion of women who achieved delivery within 24 hours. Median cervical dilation after Foley balloon expulsion was higher in the 60-mL Foley balloon group (4 cm compared with 3 cm, P<.01). There were no differences in the frequencies of cesarean delivery, maternal morbidity, or neonatal outcomes. CONCLUSION: Labor induction using Foley balloons inflated to 60 mL was more likely to achieve delivery within 12 hours compared with 30-mL inflation. There were no differences in delivery within 24 hours, cesarean delivery, labor complications, or neonatal outcomes.

Obstet Gynecol. 2010 Jun;115(6):1239-45

Mechanical methods for induction of labour.Boulvain M; Cochrane Database Syst Rev 2001;

(4):CD001233.• Compared with with misoprostol, the effectiveness of mechanical

methods was similar (34% versus 30%; relative risk (RR) 1.15; 95% CI: 0.80-1.66). The use of mechanical method reduced the risk of hyperstimulation with fetal heart rate changes when compared with prostaglandins: vaginal PGE2 (0% versus 6%; RR 0.14; 95% CI: 0.04-0.53), intracervical PGE2 (0% versus 1%; RR 0.21; 95% CI: 0.04-1.20) and misoprostol (4% versus 9%; RR 0.41; 95% CI: 0.20-0.87). There was no difference in the risk of caesarean section between mechanical methods and prostaglandins. Serious neonatal (three cases) and maternal morbidity (one case) were infrequently reported. When compared with oxytocin, use of mechanical methods reduced the risk of caesarean section (4 trials; 198 women; 17% versus 32%; RR 0.55; 95% CI: 0.33-0.91). The risk of hyperstimulation was reduced when compared with prostaglandins (intracervical, intravaginal or misoprostol). Compared to oxytocin in women with unfavourable cervix, mechanical methods reduce the risk of caesarean section.

Use Foley Bulb Alone

• The addition of oxytocin , Cytotec, or any other prostaglandin has not been demonstrated to add any benefit to the effectiveness of the induction.

• The only consistent outcome is that anesthesia / analgesia is required earlier and more often with the addition of other agents with no benefit

• SO let the uterus relax while the Foley bulb is in place

Transcervical Foley catheter with and without oxytocin for cervical ripening: a

randomized controlled trial.• RESULTS: Results were available for 183 (92 treatment, 91 control)

of 200 patients randomly assigned. There were no differences in proportions of deliveries-overall (65% compared with 60%; relative risk [RR]1.08, 95% confidence interval [CI]0.86-1.35, number needed to treat 21) or vaginal (48% compared with 46%; RR 1.04, 95% CI 0.76-1.41, number needed to treat 60)-in 24 hours, or cesarean deliveries or times to deliveries between treatment or control groups. Rates of complications were comparable; however, the treatment group had a higher proportion of regional analgesia requirement during induction than controls (23% compared with 9%, P=.01; RR 2.60, 95% CI 1.21-5.56). CONCLUSION: Addition of oxytocin to transcervical Foley catheter does not shorten the time to delivery and has no effect on the likelihood of delivery within 24 hours or vaginal delivery rate, although there is an increased use of analgesia by these patients during ripening. The use of oxytocin in addition to Foley catheter ripening is not justified.

Obstet Gynecol. 2008 Jun;111(6):1320-6

A prospective randomized controlled trial that compared misoprostol, Foley catheter, and

combination misoprostol-Foley catheter for labor induction.

• RESULTS: Among 146 patients, 49 patients were assigned to misoprostol, 54 patients were assigned to Foley catheter, and 43 patients were assigned to combination therapy. There was no difference in vaginal delivery rates (misoprostol, 63.3%; Foley, 57.4%; combination, 58.1%; P=.81). There were also no statistically significant differences in the interval between induction to active phase, active phase to delivery, or induction to delivery among the three groups. CONCLUSION: Intravaginal misoprostol and intracervical Foley catheter are comparable for preinduction cervical ripening. The combination of the two methods did not provide additional efficacy.

Am J Obstet Gynecol 2003 Oct;189(4):1031-5.

Labour induction at term--a randomised trial comparing Foley catheter plus titrated oral

misoprostol solution, titrated oral misoprostol solution alone, and dinoprostone.

• RESULTS: In the Foley catheter group, misoprostol was required in all but 1 case. Failure to deliver vaginally within 24 hours was similar for the three groups (79/174 v. 70/176 v. 70/176 respectively). Labour augmentation, caesarean section and instrumental delivery were used somewhat more frequently in the Foley/misoprostol group than in the misoprostol alone group, but these differences were not statistically significant. More analgesia was used in the Foley catheter/misoprostol group than in the misoprostol group (64/172 v. 46/175). Side-effects and neonatal complications were similar for the three groups. CONCLUSIONS: Use of extra-amniotic Foley catheter placement showed no measurable benefits over the use of oral misoprostol alone, or vaginal dinoprostone.

S Afr Med J 2003 May;93(5):375-9.

Rupture of Membranes Prior to or with Foley inPlace

• There are no data specifically looking at risk of infection with respect to duration of ruptured membranes before and/or after insertion of a balloon catheter. Some studies do not place balloon catheters in women with ruptured membranes, some studies remove the catheter if membranes rupture at any time after placement, others limit the duration of cervical ripening to 12 hours if membranes rupture after placement. There is no consensus on optimal management with rupture of membranes as described above

HOW TO PLACE a FOLEY BULB • Foley catheter (#16-#18 tip removal optional) and @ least a 30 mL balloon).

The catheter may be inserted under direct visualization into the extra amniotic space using a sterile speculum after cleaning the cervix with antiseptic solution. If dilated or favorable enough may consider digital insertion.

• Ring forceps may be used to facilitate passage of the Foley through the internal os. If necessary ultrasound can ensure the Foley is in the extra amniotic space. The balloon should be distended with saline (@ least 60 ml and up to 80 ml ) with subsequent gentle traction applied so that the distended bulb is applied to the internal os. Either attach one liter of fluid to the end of the catheter and suspend it from the end of the bed OR apply moderate traction and secure the Foley with tape to the patients thigh.

• Foley placement is possible even if the cervix is not dilated. If it is difficult to pass the Foley, a uterine sound can be used to facilitate placement; OR a urologic sound can be placed inside the Foley catheter and used as a “guide wire” to direct placement.

• The Foley is left in place until it is extruded (typically within 12 hours). Consideration for removal should be made if spontaneous rupture of membranes occurs while the Foley is in place.

• I am recommending removal @ 12 hours if spontaneous expulsion has not occurred @ that time. There is no consistent increase risk of infection following the above protocol

• Contraindications : SROM prior to placement of Foley bulb, Placental edge with 2 cm of the internal os, Intraamniotic infection, Active labor ( painful & persistent contractions every 3 minutes or less )

Cochrane Database Syst Rev 2001 Am J Obstet Gynecol 2004 Nov;191(5):1632Obstet Gynecol 2010;115:1239

The Efficacy of a Foley Bulb Induction has been Associated with

How Distended the Bulb is

• Use a 30 ml Foley bulb which will distend well beyond the 30 ml bulb size. 60-80 ml works better than 30 ml

• Distend to a -60 ml minimum -80 ml maximum -50 ml maximum if a VBAC induction

Foley Bulb Placement Commits the patient to Delivery

• Do NOT discharge a patient to home after placement of a Foley Bulb in the extra amniotic Space.

• The safety of this practice has not been studied.

• Prior to placement of a Foley Bulb discuss with the patient the possibility of a 2 day induction dependent on Modified Bishop Score