The effect of a prolonged time interval between antenatal corticosteroid administration and delivery on outcomes in preterm neonates: a cohort study.

OBJECTIVE: This study was undertaken to determine whether the neonatal benefit of a single complete course of antenatal corticosteroids diminishes when delivery is remote from administration (> 14 days).

STUDY DESIGN: This retrospective 2 center cohort trial included women who received a single complete course of antenatal corticosteroids and delivered a viable singleton infant between 26 and 34 weeks of gestation. Patients were divided into 1 of 2 groups on the basis of the interval from first corticosteroid dose to delivery (2-14 days and > 14 days). Neonatal outcomes among treatment groups were stratified by gestational age at delivery (< 28 weeks, > or = 28 weeks). Regression models were used to control for potential confounders.

RESULTS: Three hundred fifty-seven pregnancies were included, of which 98 women delivered at > 14 days after antenatal corticosteroids. Neonates at > or = 28 weeks of gestation and who delivered at > 14 days after antenatal corticosteroids were more likely to require surfactant therapy (60% vs 48%; p = .02) and to require ventilatory support for > 24 hours (58% vs 46%; P = .02). Differences in outcomes between groups remained in regression models that were controlled for confounders. There was no significant difference between treatment groups for neonates who delivered at < 28 weeks of gestation. Rates of survival without chronic lung disease and intraventricular hemorrhage were similar between groups.

CONCLUSION: A time interval of > 14 days between the administration of antenatal corticosteroids and delivery is associated with an increased risk for ventilatory support and surfactant use in neonates who deliver at > 28 weeks of gestation.