Changes in mortality, morbidity and early neurodevelopmental outcomes among extremely-low-birth-weight (ELBW) infants born in the early and recent post-surfactant era

Abstract

Advances in perinatal medicine and the introduction of surfactant replacement therapy (SRT) have significantly improved the outcomes for extremely-low-birth-weight (ELBW) infants (defined as birth weight less than or equal to 1000 gram). We studied a retrospective cohort of 234 ELBW babies born between 1993 and 2002 at a tertiary perinatal centre. The mean birth weight was 762±144 gram (mean±SD) with mean gestational age of 26.2±2.4 weeks (mean±SD). Changes in mortality, major morbidity and early neurodevelopment outcomes were compared by dividing them into 2 periods vis the early surfactant era (1993-1996) and the recent surfactant era (1997-2002). The major change in the recent surfactant era has been the adoption of early rescue therapy by natural surfactant for all babies requiring ventilator support. Improvement in survival till discharge (84.7% compared with 56.4%, p<0.001), higher prevalence in use of antenatal steroid (66.7% compared with 38.6%, p<0.001), fewer babies born with 1-minute Apgar Score ≤3 (29.0% compared with 48.1%, p=0.002), shorter duration of mechanical ventilation (16.7±18.2 days compared with 26.7±21.0 days, p=0.001), and reduction in prevalence of retinopathy of prematurity (16.2% compared with 29.0%, p=0.049) and severe intra-ventricular hemorrhage (13.6% compared with 30.0%, p=0.002) were noted among the babies in the recent surfactant era. These were not associated with any significant increase in prevalence of cerebral palsy, hearing and visual impairment and low General Developmental Quotient among 126 infants (75.4% of survivors) who attended our neurodevelopmental assessment with a mean corrected age of 19.0±2.2 months. Differences between the early and recent groups suggest that advances in perinatal and neonatal intensive care, in addition to early rescue surfactant therapy contribute to improved survival and neonatal outcomes of ELBW infants. Despite the increasing number of ELBW survivors, there was no increase in adverse early neurodevelopment outcomes.