Late Preterm Corticosteroids Exposure and Neurodevelopmental Outcomes

In recent years, there has been a reevaluation of the upper gestational age limit recommended for administration of antenatal corticosteroids. Seven randomized clinical trials (RCTs) published between 2010 and 2022 have evaluated the effects of expanding the limit from 34 to 37 weeks’ gestation. The largest of these was the Antenatal Late Preterm Steroids (ALPS) trial published in 2016. In this trial, the administration of antenatal corticosteroids yielded a 20% relative reduction in the primary outcome (respiratory morbidity). The absolute reduction in the primary outcome was only 2.8% (from 14.4% to 11.65%), and the effect of antenatal corticosteroids was essentially limited to a reduction in the transient tachypnea of the newborn. There was no discernable benefit of corticosteroids on mortality, respiratory distress syndrome, necrotizing enterocolitis, or intraventricular hemorrhage. Conversely, corticosteroids were associated with a 40% increase in neonatal hypoglycemia (from 15% to 24% in the treated group). Subanalysis suggested that the benefit on respiratory morbidity declined with increasing gestational age, being limited to infants born before 35 weeks’ gestation, whereas the incidence of neonatal hypoglycemia increased over the same interval.