Neonatal Outcomes Based on Duration of Exposure to Antenatal Corticosteroids in Indicated Preterm Deliveries.

Objective: To evaluate how duration of exposure to antenatal corticosteroids (ACSs) prior to delivery affects neonatal outcomes in indicated preterm deliveries.
Study Design: This is a retrospective cohort of all indicated singleton preterm deliveries (23-34 weeks) in a single tertiary center from 2011 to 2014 comparing those who received ACS 2 to 7 days versus >7 days prior to delivery. The primary neonatal outcome was a composite of arterial cord pH < 7 or base excess ≤ 12, 5-minute Apgar ≤ 3, cardiopulmonary resuscitation, culture-proven neonatal sepsis, intraventricular hemorrhage grade III/IV, necrotizing enterocolitis, and neonatal death. Analyses were stratified by delivering gestational age (23 ^0/7 -27 ^6/7 , 28 ^0/7 -31 ^6/7 , and 32 ^0/7 -33 ^6/7 weeks). Multivariate logistic regression refined point estimates and adjusted for confounders.
Results: In total, 301 women delivered >48 hours after initial ACS dose, 230 delivered within 2 to 7 days, and 71 delivered >7 days. Infants with an interval of >7 days had no significant increase in the unadjusted composite neonatal outcome ( p  = 0.42), but when adjusted, the composite neonatal outcome (adjusted odds ratio [AOR]: 2.7; 95% confidence interval [CI]: 1.18-6.31) and neonatal death (AOR: 4.20; 95% CI: 1.39-12.69) were significantly increased with an ACS interval of >7 day.
Conclusion: In this cohort, the benefit of ACS diminished >7 days after administration, particularly when delivery occurred at <32 weeks.
Competing Interests: None.
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