Antenatal Corticosteroid in Twin-Pregnant Women at Risk of Late Preterm Delivery: A Randomized Clinical Trial.

Summary

In 812 twin pregnancies at 34–36+5 weeks, antenatal betamethasone reduced severe neonatal respiratory morbidity (RR 0.64) and decreased CPAP ≥2 h use and transient tachypnea, with no perinatal deaths in either arm. Benefits were time-dependent (delivery 12 h to <7 days after dosing), while neonatal hypoglycemia was more frequent in the steroid group.

Key Findings

• Severe neonatal respiratory morbidity: 4.8% with betamethasone vs 7.5% with placebo (RR 0.64, 95% CI 0.42–0.98).
• Lower CPAP use ≥2 h (RR 0.58, 95% CI 0.35–0.95) and lower transient tachypnea of the newborn (RR 0.47, 95% CI 0.25–0.89).
• Efficacy observed only when delivery occurred 12 h to <7 days after the first dose.
• Neonatal hypoglycemia increased with betamethasone (15.6% vs 11.7%; RR 1.33, 95% CI 1.01–1.75).
• No perinatal deaths; no difference in neonatal sepsis or maternal chorioamnionitis.

Clinical Implications

For twin pregnancies at risk of late preterm birth, consider antenatal betamethasone to reduce neonatal respiratory morbidity, optimizing timing so delivery occurs 12 hours to <7 days after the first dose; implement glucose monitoring protocols to manage increased neonatal hypoglycemia.

Limitations

• Conducted in a single country (Korea), which may limit generalizability.
• Not powered to assess rare adverse outcomes; benefit was time-window dependent.

Future Directions

Replicate findings across diverse populations, refine optimal dosing-to-delivery timing strategies in twins, and evaluate metabolic mitigation protocols to reduce hypoglycemia risk.