Antenatal steroids for treatment of fetal lung immaturity after 34 weeks of gestation: An evaluation of neonatal outcomes

OBJECTIVE:: To estimate whether antenatal corticosteroids given after fetal lung immaturity in pregnancies at 34 weeks of gestation or more would improve neonatal outcomes and, in particular, respiratory outcomes. METHODS:: We compared outcomes of 362 neonates born at 34 weeks of gestation or more after fetal lung maturity testing: 102 with immature fetal lung indices were treated with antenatal corticosteroids followed by planned delivery within 1 week; 76 with immature fetal lung indices were managed expectantly; and 184 were delivered after mature amniocentesis. Primary outcomes were composites of neonatal and respiratory morbidity. RESULTS:: Compared with corticosteroid- exposed neonates those born after mature amniocentesis had lower rates of adverse neonatal (26.5% compared with 14.1%, adjusted odds ratio [OR] 0.51, 95% confidence interval [CI] 0.27-0.96) and adverse respiratory outcomes (9.8% compared with 3.3%, adjusted OR 0.33, 95% CI 0.11-0.98); newborns born after expectant management had significantly less respiratory morbidity (1.3% compared with 9.8%, adjusted OR 0.11, 95% CI 0.01-0.92) compared with corticosteroid-exposed newborns. CONCLUSION:: Administration of antenatal corticosteroids after immature fetal lung indices did not reduce respiratory morbidity in neonates born at 34 weeks of gestation or more. Our study supports prolonging gestation until delivery is otherwise indicated.