Can corticosteroids be effective hours before delivery?
Administering antenatal corticosteroids only hours prior to delivery may improve survival in very preterm infants, according to results of a Swedish study published in JAMA Pediatrics.
Researchers used data from the Effective Perinatal Intensive Care in Europe study, which gathered information from 19 regions across 11 European countries from 2011 to 2013. The cohort included 4594 singleton infants with a gestational age range of 24 to 31 weeks. The infants did not have severe anomalies and were not otherwise exposed to multiple courses of antenatal corticosteroids. The authors studied 3 outcomes: severe neonatal brain injury, which was defined as an intraventricular hemorrhage grade 3 or greater or cystic periventricular leukomalacia; composite of mortality or severe neonatal morbidity, which was defined as an intraventricular hemorrhage grade of 3 or greater, cystic periventricular leukomalacia, surgical necrotizing enterocolitis, or stage 3 or greater retinopathy of prematurity; and in-hospital mortality.
Of the infants in the cohort, 2496 were boys. The average gestational age was 28.5 weeks and the average birth weight was 1213 g. Among the 662 infants unexposed to antenatal corticosteroids, the mortality rate was 20.6% (136 of 661). Administering antenatal corticosteroids was linked with a rapid and immediate decline in mortality, which plateaued with over 50% risk reduction where administration-to-birth interval was 18 to 36 hours. A similar pattern was seen for composite mortality or morbidity outcome. An administration-to-birth interval of more than 48 hours was linked with a significant reduction in the risk of severe neonatal brain injury. The risk reduction association was antenatal corticosteroids was transient and an administration-to-birth interval exceeding 1 week was associated with increasing mortality and risk of severe neonatal brain injury.
Based on the assumption that a causal relationship existed between mortality and timing of antenatal corticosteroids, the researchers performed a simulation which demonstrated that administering the drugs 3 hours before delivery to infants who had no previous exposure was associated with an estimated decline in mortality of 26%. They concluded that, contrary to previous hypotheses, administration of antenatal corticosteroids in a few hours prior to delivery may prove effective for improving survival and decreasing neonatal morbidity in very preterm infants.