NEONATAL MORBIDITY AFTER PRETERM DELIVERY IN THE PRESENCE OF DOCUMENTED LUNG MATURITY

OBJECTIVE: Our purpose was to determine the incidence of significant n eonatal morbidity in fetuses with documented pulmonary maturity delive red before 37 weeks' gestation STUDY DESIGN: A retrospective review of 213 pregnancies with documented fetal lung maturity (lecithin/sphingo myelin ratio greater-than-or-equal-to 2.0 or phosphatidylglycerol pres ent) and delivery before 37 weeks was performed. The incidence of neon atal respiratory distress syndrome, bronchopulmonary dysplasia, grade 3 or 4 intraventricular hemorrhage, necrotizing enterocolitis, patent ductus arteriosus, retinopathy of prematurity, infectious morbidity, h yperbilirubinemia, and admission to the special care nursery was deter mined for those pregnancies with intact membranes and preterm prematur e rupture of membranes. RESULTS: Serious neonatal morbidity declined w ith advancing gestational age and was less common after 32 completed w eeks of pregnancy. Although the frequencies of respiratory,distress sy ndrome, grade 3 or 4 intraventricular hemorrhage, and necrotizing ente rocolitis were 19.4% (12/62), 8.1% (5/62), and 4.8% (3/62), respective ly, at less-than-or-equal-to 33 weeks' gestation, one case of respirat ory distress syndrome, one case of grade 3 intraventricular hemorrhage , and one case of necrotizing enterocolitis occurred in the 151 neonat es born at greater-than-or-equal-to 34 weeks' gestation. CONCLUSIONS: In spite of fetal lung maturity major neonatal morbidity was observed in our patient population. These data relating neonatal morbidity to g estational age are useful in the critical decision regarding timing of delivery.