Respiratory disease syndrome (RDS) is one of the leading causes of early neonatal morbidity and mortality. Prophylactic corticosteroids are known to accelerate lung maturation and reduce the incidence of RDS in singleton preterm pregnancies. This study investigates the efficacy of antenatal corticosteroids in infants with the gestational age of 34 weeks or more.

This was a systematic review and meta-analysis of 6 randomized clinical trials analyzing the effects of antenatal corticosteroids in women with a singleton pregnancy at ≥34 weeks’ gestation. The primary outcome of the study was the incidence of severe RDS reported as relative risks.

The 6 included trials consisted of a total of 5,698 singleton pregnancies. Three out of 6 trials included 3,200 women at 34-36 weeks’ gestation and at risk of imminent premature delivery. The 3 remaining trials included 2,498 women undergoing planned cesarean delivery at ≥37 weeks. The findings suggested that infants born to mothers who received antenatal corticosteroids at ≥34 weeks were at a lower risk of RDS (relative risk 0.74), moderate RDS (0.39), and severe RDS (0.55).

The research concluded that infants born to mothers who received antenatal steroids at ≥34 weeks’ gestation were at a lower risk of mild, moderate, and severe RDS.