Antenatal Late Preterm Steroids: A Randomized Placebo Controlled Trial

The Antenatal Late Preterm Steroids Trial (ALPS) was a randomized, multicenter, double-blind trial to determine whether antenatal corticosteroids given to women at high risk for late preterm birth (34 weeks to 36 weeks) reduces stillbirth or the need for neonatal respiratory support of preterm birth or neonatal death in the first 72 hours. Women with a singleton pregnancy at 34-36 weeks who were at high risk for preterm delivery were randomized to 2 injections of betamethasone or matching placebo 24 hours apart. There were 2831 women randomized; 4 were lost to follow-up. The primary outcome occurred in 165 infants (11.6%) in the betamethasone group and 202 (14.4%) in the placebo group (RR 0.80; 95% CI, 0.66-0.97; p=0.02). Severe respiratory complications, transient tachypnea of the newborn, surfactant use, and bronchopulmonary dysplasia also occurred significantly less frequently in the betamethasone group. Neonatal hypoglycemia was more common in the betamethasone group (p<0.001).