Association Between Antenatal Corticosteroid Administration-to-Birth Interval and Outcomes of Preterm Neonates

OBJECTIVE: To assess the association between antenatal corticosteroid administration-to-birth interval and outcomes. METHODS: In this retrospective cohort study, data on singleton neonates born between 24 0/7 and 33 6/7 weeks of gestation and admitted to tertiary neonatal units in Canada during 2010-2012 were obtained from the Canadian Neonatal Network. Neonatal outcomes were compared among four groups based on the interval between antenatal corticosteroid administration and birth: no antenatal corticosteroids, partial antenatal corticosteroids (less than 24 hours before birth), antenatal corticosteroids 1-7 days before birth, and antenatal corticosteroids greater than 7 days before birth. Composite outcome was defined as any of neonatal mortality, bronchopulmonary dysplasia, grade 3-4 intraventricular hemorrhage, periventricular leukomalacia, or stage 3 or higher retinopathy. RESULTS: Of 6,870 eligible neonates, 1,378 (20%) received no antenatal corticosteroids; 1,473 (21%) received partial antenatal corticosteroids; 2,721 (40%) received antenatal corticosteroids 1-7 days before birth; and 1,298 (19%) received antenatal corticosteroids greater than 7 days before birth. The odds of the composite adverse outcome were significantly higher in all groups compared with neonates who received antenatal corticosteroids 1-7 days before birth (no antenatal corticosteroids: adjusted odds ratio [OR] 2.12, 95% confidence interval [CI] 1.69-2.65; partial antenatal corticosteroids: adjusted OR 1.48, 95% CI 1.22-1.80; and antenatal corticosteroids at greater than 7 days: adjusted OR 1.46, 95% CI 1.20-1.77). Similar findings were observed with respect to neonatal mortality (no antenatal corticosteroids: adjusted OR 2.56, 95% CI 1.83-3.59; partial antenatal corticosteroids: adjusted OR 1.59, 95% CI 1.16-2.18; and antenatal corticosteroids at greater than 7 days: adjusted OR 1.40, 95% CI 1.00-1.97). CONCLUSION: Antenatal corticosteroids had maximum benefit when given between 1 and 7 days before birth.