Are Prenatal Steroids Effective in Late Preterm Infants?

Prenatal steroids are clearly effective in reducing morbidity and mortality in preterm infants <34 weeks' gestation but the effectiveness in late preterm infants (34–36 weeks' gestation) is less certain. Researchers in Brazil randomized 320 women at 34–36 weeks' gestation who were at risk of imminent delivery to receive prenatal steroids (12 mg of betamethasone) or placebo intramuscularly for 2 days. The analysis included 143 infants in the steroid group and 130 in the placebo group.

The rate of respiratory distress syndrome was low in both groups (2 cases in the steroid group and 1 in the placebo group). Rates of transient tachypnea were similar in the two groups (24% and 22%, respectively), as were need for ventilator support (about 20%) a…