Antenatal Betamethasone: A Prolonged Time Interval from Administration to Delivery Is Associated with an Increased Incidence of Severe Intraventricular Hemorrhage in Infants Born before 28 Weeks Gestation

OBJECTIVE: To examine the effects of antenatal steroids on severe intraventricular hemorrhage (IVH) in infants born during the IVH vulnerable period (<28 weeks gestational age) and to evaluate rates of IVH correlated with the time interval between treatment or retreatment and birth. STUDY DESIGN: A total of 429 infants (<28 weeks gestation), who delivered ≥24 hours after the first betamethasone (BMZ) course (2 doses), were divided into groups based on the interval between the first course of BMZ and delivery: <10 days or ≥10 days. The primary outcome was severe IVH. Multiple regression analyses were performed to adjust for potential confounders. RESULTS: Three hundred ninety-two infants delivered after a single BMZ course (312 delivered <10 days; 80 ≥10 days). The incidence of severe IVH was 17% for infants delivered ≥10 days and 7% for those delivered <10 days after a single BMZ course (aOR 4.16; 95% CI 1.59-10.87, P = .004); 37 infants (born ≥10 days from the first BMZ course) received a second/rescue BMZ course. The incidence of severe IVH among infants receiving a second/rescue course was 8%, which was similar to the incidence among infants born <10 days (aOR 1.7; 95% CI 0.41-6.6, P = .48). CONCLUSIONS: In infants born before 28 weeks gestation, delivery ≥10 days from the first BMZ course is associated with a higher incidence of severe IVH; a second/rescue course may reverse this effect.