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, ≥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 ≥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.

Key words: antenatal steroid, latency, neonatal morbidity, premature