short-term outcome of high-risk newborns

Apollo Medicine 2011 DecemberReview Article

Volume 8, Number 4; pp. 266–269

© 2011, Indraprastha Medical Corporation Ltd

Short-term outcome of high-risk newborns

Vikram Singh*, Anjali Kulkarni**, Vidya Gupta**, Sushma Kaul**, Saroja Balan***Neonatal Fellow, **Senior Consultant, Neonatologist, Division of Neonatology, Apollo Center for Advanced Paediatrics,Indraprastha Apollo Hospitals, Sarita Vihar, New Delhi – 110076, India.

ABSTRACT

A prospective observational study was conducted in the Neonatal Unit of Indraprastha Apollo Hospital over a period of 10 months. A total of 86 high-risk newborns were included to study the mortality and morbidity patterns. Majority of these (68%) were outborn male babies: 65% were pre-term and 36% were low birth weight. Overall survival was 77.2% and was better in inborn babies. Survival was directly proportional to gestation and birth weight. Systemic infection was associated with higher mortality and morbidity. Klebsiella was the commonest organism cultured fol-lowed by Candida. Hyaline membrane disease was the commonest respiratory morbidity. Sixty-seven percent required ventilatory support, and mortality was directly proportional to the duration of ventilation. Only 6% of the survivors had neurodevelopmental delay at 6 months and one baby had hearing impairment requiring cochlear implant. They continue to be on long-term follow-up.

Keywords: Morbidity, newborn, risk factors, survival

Correspondence: Dr. Anjali Kulkarni, E-mail: [email protected]: 10.1016/S0976-0016(11)60003-3

INTRODUCTION

Babies who were exposed to high-risk factors before birth, during birth or during their newborn periods are likely to have adverse outcomes. Advances in perinatal care and establishment of improved neonatal services have increased the survival rates of many high-risk newborns in develop-ing countries.

The outcome of these babies in Western world where infrastructure, manpower, technology, and patient load are different cannot be extrapolated to Indian babies. There is a need to systematically report the outcome of these neonates in Indian setting, so as to help neonatologist, obstetrician, parents, and health planners in achieving better results.

OBJECTIVE OF THE STUDY

Primary

To evaluate:• all high-risk newborns both inborn and transferred from

other hospitals for survival,• the causes of perinatal and neonatal death.

Secondary

• To generate and disseminate prospective data on neonatal–perinatal morbidity among high-risk newborns with focus on:– incidence of low birth weight (LBW) and prematurity– incidence and outcome of birth asphyxia– organisms causing infections in neonates– incidence of other morbidity, such as respiratory dis-

tress, hyperbilirubinemia, and intraventricular hemor-rhage.

• To compare the outcome between intramural and extra-mural newborns.

MATERIALS AND METHODS

This was a prospective observational study over a period of 10 months from 1 December 2009 to 30 September 2010. The data were collected from babies admitted to the neona-tal unit at the Indraprastha Apollo Hospitals, New Delhi.

Selection of high-risk neonates was based on the gestational age, birth weight, occurrence and severity of perinatal/neonatal illness, and intervention received in the

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neonatal intensive care unit. Cohort of high-risk neonates has the following inclusion and exclusion criteria:

Inclusion Criteria

• Newborns with <1800 g birth weight and/or gestation < 35 weeks.

• Small for date <3 percentile and large for date >97 percentile.• Perinatal asphyxia, American paediatric gross assessment

record (APGAR) score <3 or less at 5 minutes and/or hypoxic ischemic encephalopathy.

• Mechanical ventilation for > 24 h.• Metabolic problems: Hypoglycemia and hypocalcemia.• Seizures.• Infections: Meningitis and/or culture positive sepsis.• Shock requiring inotropic/vasopressor support.• Major morbidity such as chronic lung disease, intraven-

tricular hemorrhage and periventricular leucomalacia.• Hyperbilirubinemia serum bilirubin > 20 mg/dL or

requiring exchange transfusion.

Exclusion Criteria

• All legally nonviable babies ≤ 23 weeks or ≤ 500 g.• All babies with major congenital malformations/syndromes.

RESULTS

A total of 86 high-risk newborns were enrolled in the study period of 10 months. Most of the babies were extramural (68.6%) and were referred or transported to idiopathic adre-nal hyperplasia (IAH). There were more male babies (68.6%) as compared with female (31.3%). The demographic features are depicted in Table 1.

Lower segment cesarean was the most common mode of delivery (76.7%). Majority of the babies required routine resuscitation (60.4%), 24.4% babies required intubation at birth of which 5.8% were for meconium. Most of the babies had APGAR score of > 7 at 1 minute (50%) and 23.2% had scores of < 4 at 1 minute. At 5 minutes, 54.6% babies had APGAR scores of > 7 and only 8.1% had scores < 4.

Most of the babies in our study were preterm (65.1%) and had birth weight < 2500 g (36%). The incidence of very low birth weight (VLBW) was 22% and extremely low birth weight (ELBW) was 10.4%.

Hyaline membrane disease was the most common res-piratory morbidity (43%) followed by meconium aspiration

(11.6%). Air leak due to ventilation was seen in only 4.6% of the babies. Seizures was the most common central ner-vous system (CNS) morbidity (16.2%). Other common mor-bidities seen were hypoglycemia (18.6%), anemia (15.1%), and hypocalcemia (13.9%). Only 5.8% of the babies devel-oped retinopathy of prematurity (ROP) of which only 50% required laser therapy.

Systemic infection was one of the most common causes of mortality and morbidity in our study. Overall incidence of systemic infection was 50%, majority of which were late onset (40.6%). Bacterial septicemia was the most common form of systemic infection (37.2%) (Table 2). Most common organ-ism isolated in cases of systemic infection in our study was Klebsiella (12.7%), followed by fungus (8.1%) (Table 3).

Septicemia following necrotizing enterocolitis (NEC) was seen in 8.1% and meningitis was seen in 4.6%.

DISCUSSION

According to the National Neonatal Perinatal Database (NNPD) 2002–2003 data,1 the incidence of prematurity in India is 14.5%. This means that India has an annual incidence of 3–4 million preterm live births which is a huge number.

Our incidence was very high compared with the national incidence probably because our hospital is a referral center, and only high-risk newborns were included in the study.

Table 1 Demographic characteristics.

Category No. of neonates Proportion (n = 86) (%)

Sex distribution Male 59 68.6 Female 27 31.3

Gestation group Pre-term (< 37 wk) 56 65.1 Term 30 34.8 Post-term (> 41 wk) 0 0.0

Birth weight (g) LBW < 2500 31 36.0 VLBW < 1500 19 22.0 ELBW < 1000 9 10.4

Intrauterine growth Small for date 20 23.2 AGA 56 65.1 Large for date 1 0.01

LBW: low birth weight; VLBW: very low birth weight; ELBW: extremely low birth weight; AGA: accelerated growth area.

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268 Apollo Medicine 2011 December; Vol. 8, No. 4 Singh et al


Worldwide, approximately 12.9 million babies are born preterm every year with a global prevalence of 9.6%. The regional toll of preterm birth is particularly heavy for Africa and Asia where over 85% of all pre-term births occur. Rates of pre-term birth by regional level of development are high-est for low resource regions (12.5%), moderate for middle resource regions (8.8%), and lowest for high resource regions (7.5%). The average incidence of pre-term births in most developed countries has been about 9–12%. The high-est rate of pre-term birth is in Africa, followed by North America, Asia, Latin America and the Caribbean, Oceania, and Europe. An estimated 28% of the 4 million annual neo-natal deaths are due to pre-term birth.

In our study, there were 31 babies (36.0%) whose weight was < 2500 g. The incidence of VLBW was 22% and ELBW was 10.4%. The rate of VLBW babies is increasing, due mainly to the increase in prematurely born multiple ges-tations, in part related to assisted reproductive techniques.

Very low birth weight babies constitute approximately 4–7% of all live births but appropriate a major share of effort, time and resources for their care. Despite this, the mortality among this subgroup of neonate is high, contributing as much as 30% to the early neonatal mortality.

Large proportion (77.2%) of the VLBW babies in our study survived to discharge (1000–1250 g, 55.6% and 1250–1499 g, 92.4%) (Table 1). Data from research net-works suggest that approximately 85% of VLBW babies in the United States level III facilities survive to hospital dis-charge which is very close to our findings.

The incidence of survival in intramural VLBW was higher as compared with extramural, the reason being the survivability in this category also depended on the place of birth, the availability of experienced doctor, the timely transport and so on.

Similar sharp decline in the survival was noted below 26 weeks gestation in our study. None of the babies with gestational age of < 26 weeks survived. Highest survival rates were noted in babies of 33–35 weeks gestation (94%) (Table 4).

Mortality related to septicemia was highly seen in 62.5%. Rizwan et al2 have reported a mortality of 37%. Most common organism isolated in cases of systemic infec-tion in our study was Klebsiella (12.7%), followed by fun-gus (8.1%). Among intramural and extramural births from the NNPD 2002–2003, Klebsiella pneumoniae was the most frequently isolated pathogen (32.5%), followed by Staphylococcus aureus (13.6%).

Therapeutic Interventions and Final Outcome

Of the 86 patients enrolled in the study, 69.7% were dis-charged, 17.4% expired, 10.4% left treatment against medi-cal advice and 2.3% were transferred back to referring hospital.

Majority of the babies (67.4%) required assisted venti-lation. There was a direct relationship between days of ven-tilation and survival rates. Babies requiring shorter duration of ventilation (< 48 h) had a lesser mortality rate (20.0%), as

Table 3 Bacterial isolates.

Organism No. of isolates (n) Proportion (%)

Klebsiella 11 12.7CONS 4 4.6Escherichia coli 4 4.6Pseudomonas 0 0Acenetobacter 2 2.3Burkodiella 2 2.3Stenophonomonas 1 1.1Enterococcus 4 4.6Fungus 7 8.1

CONS: coagulase-negative Staphylococcus.

Table 4 Neonatal mortality in different gestational age.

Gestation No. of No. of Mortality (wk) infants deaths rate (%)

< 26 3 3 10027–29 9 5 55.530–32 16 3 18.733–35 19 1 5.2> 35 39 3 7.6

Table 2 Systemic infection.

Category No. of infants Proportion (n = 86) (%)

Overall incidence 43 50.0

Time of onset Early 1 1.1 Late 35 40.6 Not specified 7 8.1

Clinical category Septicemia 32 37.2 Meningitis 4 4.6 Pneumonia 3 3.4 NEC 7 8.1 UTI 0 0.0 Bone/joint 0 0.0

NEC: necrotizing enterocolitis; UTI: urinary tract infection.

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compared with longer duration of ventilation (> 7 days) in which the mortality rate was higher (30.4%). In a study from Pakistan, the overall mortality with documented respiratory distress was 41% and was higher (70%) in babies with birth weight < 1000 g.3

Retinopathy of prematurity requiring laser was seen in only 4 patients. As many as 27–35% infants < 1500 g birth weight and 16–48% infants < 1000 g birth weight develop some degree of ROP. The year-wise distribution of the inci-dence of ROP in our unit was 24.4% in 2000 and 27.3% in 2001. It declined to 16.7%, 19.5%, and 18.4% in 2002, 2003, and 2004, respectively. However, it rose to 26% in 2005 and 2006, as we started saving smaller babies. A study in Bengaluru (Bangalore) has reported an overall incidence of 46%.4

Total parental nutrition was used in 26 (30.3%) patients. Majority of the babies who required total parenteral nutri-tion (TPN) were preterm babies and were having NEC. The incidence of NEC in our population was 1.5% similar to 1.3% of all NICU admissions in a study by Niyaz et al.5

Blood products (fresh frozen plasma, platelets, and packed red cells) were used in 26 babies (30.2%). Blood products were mainly used in premature babies and babies developing septicemia.

Hyaline membrane disease was seen in 37 cases (43%) in our study. Thirty cases required the use of surfactant and seven cases were managed by continuous positive airway pressure.

Thirty babies (34.8%) required phototherapy. Babies who required phototherapy were mainly extramural babies. Of the 30 babies, only 9 babies had serum bilirubin above 20 mg/dL. Three exchange transfusions were performed. All babies requiring exchange transfusion were extramural and were cases of Rh isoimmunization.

Six babies (6.97%) had symptomatic patent ductus arteriosus, four babies underwent pharmacological closure and two required surgery.

The otoacoustic emission screening was routinely done at discharge. Nine babies (10.4%) had hearing deficiency at discharge. During follow-up, two babies (2.32%) required brainstem evoked response audiometry examination and were then declared normal. The remaining 6 babies were lost on follow-up. One baby (1.2%) had significant bilateral hearing loss. Zamani et al6 have reported an incidence of 3.5% in their study.

Seventy percent of babies had normal neurological examination at 3 months of age corrected for prematurity. At 6 months follow-up, only 5 babies (5.8%) had delayed milestones. One was a case of exaggerated neonatal hyper-bilirubinemia and the remaining 4 were cases of severe birth asphyxia with encephalopathy of which 3 required prolonged ventilation.

Twenty babies were lost on follow-up (23.2%), while 6.9% of the babies expired after being discharged. These were the babies which were discharged against medical advice.

CONCLUSION

The outcome of high-risk babies in tertiary care neonatal unit is reasonably good, but a meticulous approach is required to manage various neonatal complications to fur-ther reduce the mortality and long-term morbidity.

REFERENCES

1. Deorari AK. For the Investigators of the National Neonatal Perinatal Database (NNPD). Changing pattern of bacterio-logic profile in neonatal sepsis among intramural babies. J Neonatol 2006;20:8–15.

2. Rizwan W, Azahar A, Shah MQ, Khan A, Querishi W. Biomedical indicators of early outcome in neonatal sepsis. Biomedica 2005;21:Bio-13.

3. Bhutta ZA, Yusuf K. Profile and outcome of the respiratory distress syndrome among newborns in Karachi: risk factors for mortality. J Tropical Pediatr 1999;43:143–8.

4. Swarna Rekha, Battu RR. Retinopathy of prematurity: inci-dence and risk factors. From the Departments of Pediatrics and Ophthalmology, St. John’s Medical College Hospital, Bangalore. Ind Paediatr 1996;33:999–1003.

5. Niyaz AB, Ahmad M, Ali SW, Ahmad QI, Bashir C, Masood-Ud-Hassan. Neonatal necrotizing enterocolitis: a clinical study and outcome. JK-Practitioner 2001;8:237–9.

6. Zamani A, Daneshjou K, Ameni A, Takand J. Estimating the incidence of neonatal hearing loss in high risk. Acta Med Iran 2004;42:176–80.

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short-term outcome of high-risk newborns

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