Late-Preterm Antenatal Steroids for Reduction of Neonatal Respiratory Complications: A Randomized Controlled Trial.

OBJECTIVE

To evaluate the efficacy of antenatal corticosteroids in reducing neonatal respiratory complications when administered to those at risk of preterm delivery between 34 and 36 6/7 weeks of gestation.

METHODS

This was a single-center, triple-blind, randomized, placebo-controlled trial in southern India enrolling pregnant participants at risk of preterm delivery between 34 and 36 6/7 weeks of gestation. Computer-generated block randomization was used with participants randomized to either one course of intramuscular betamethasone or placebo. The primary outcome was a composite of treatment for respiratory distress in the neonate, defined as need for oxygen or continuous positive airway pressure or mechanical ventilation for at least 2 hours in the first 72 hours of life. Neonatal secondary outcomes were transient tachypnea of the newborn, respiratory distress syndrome, necrotizing enterocolitis, sepsis, hyperbilirubinemia, hypoglycemia, stillbirth, and early neonatal death; maternal secondary outcomes were chorioamnionitis, postpartum hemorrhage, puerperal fever, and length of hospitalization. All analyses were based on intention to treat. A sample size of 1,200 was planned with 80% power to detect a 30% reduction in rates of respiratory distress. After a planned interim analysis, enrollment was stopped for futility.

RESULTS

From March 2020 to August 2022, 847 participants were recruited, with 423 participants randomized to betamethasone and 424 participants randomized to placebo. There were 22 individuals lost to follow-up. There was no statistically significant difference in the primary outcome (betamethasone 4.9% vs placebo 4.8%, relative risk 1.03, 95% CI, 0.57-1.84, number needed to treat 786). There were no statistically significant differences in secondary neonatal or maternal outcomes.

CONCLUSION

Betamethasone administered in the late-preterm period to those at risk for preterm delivery did not reduce the need for treatment of neonatal respiratory distress.

CLINICAL TRIAL REGISTRATION: Clinical Trials Registry of India, CTRI/2019/09/021321.