Changes in Survival and Neonatal Morbidity in Infants with a Birth Weight of 750 g or Less

Background: Improvement in perinatal and neonatal care has resulted in increased survival of extremely low birth weight (ELBW) infants. Objectives: To describe survival and neonatal morbidity in a cohort of ELBW infants, to compare two consecutive 5-year periods, and compare appropriate (AGA) with small for gestational age (SGA) infants (AGA >= p10, and SGA <p10). Methods: Retrospective cohort study of 179 live-born infants with a birth weight (BW) of <= 750 g and gestation of 6 24 weeks, born in 1996-2000 (cohort I, n = 94) and 2001-2005 (cohort II, n = 85) in the Wilhelmina Children's Hospital Utrecht, the Netherlands. Results: During NICU stay (n = 146) 62.3% experienced infant respiratory distress syndrome (IRDS), 46.6% bronchopulmonary dysplasia, 50.7% septicemia, 34.2% periventricular leukomalacia grade I and 24.7% intraventricular hemorrhage grade I/II. IRDS grade III/IV occurred significantly more often in cohort I (p = 0.042), whereas septicemia and hyperbilirubinemia occurred more in cohort II (p = 0.045 and p = 0.001). In AGA infants mean gestation was significantly shorter (p < 0.001), and IRDS grade III/IV (p = 0.015), mechanical ventilation (p = 0.045) and patent ductus arteriosus (p = 0.003) were significantly more prevalent. Overall survival was 62%, and survival in the NICU increased from 65.8% (cohort I) to 88.1% (cohort II, p = 0.002). Survival of AGA and SGA infants did not differ, but increased with time (71.4 to 75.9% and 61.4 to 97.4%, respectively). Conclusions: Mortality of infants with a BW of <= 750 g is high, but decreased over time, especially in SGA infants. Considerable neonatal morbidity was present, especially in AGA infants, most likely due to their significantly shorter gestation. Copyright (C) 2010 S. Karger AG, Basel