Neonatal morbidity occurs despite pulmonary maturity prior to 39 weeks gestation

Objective—To compare outcomes among late-preterm or early-term neonates according to fetal lung maturity status. Study Design—We conducted a retrospective cohort study of 234 eligible singletons delivered after fetal lung maturity (FLM) testing prior to 39 weeks gestation at our center over a two year time period. A primary composite neonatal outcome included death and major morbidities. Results—The overall rate of primary composite morbidity was 25/46 (52.2%) and 61/188 (32.4%) in the immature/transitional and mature groups, respectively. After adjustment for confounders including gestational age, the composite outcome was not significantly different; aOR 1.4 (CI 0.7-3.0). The rate of respiratory distress syndrome was significantly higher in the immature/transitional group; OR 3.4 (CI 1.1-10.3) as expected. Conclusions—FLM status did not correlate with the spectrum of neonatal morbidities in late preterm and early term births. Neonatal complications remained common in both groups. Keywords fetal lung maturity; late preterm birth; amniocentesis; neonatal outcomes; prematurit