Antenatal betamethasone lowers risk of respiratory morbidity in late preterm twin neonates

Antenatal administration of betamethasone in women with twin pregnancies at risk of late preterm delivery appears to reduce the risk of neonatal respiratory morbidity, as shown in a study.

The study included 812 twin-pregnant women (median age 35 years) at 34–36 weeks of gestation who were at risk of late preterm delivery. These participants were randomly assigned to receive two injections of betamethasone (n=410) or placebo (n=402).

The primary outcome was perinatal death within 72 hours after birth or severe neonatal respiratory morbidity. Mild neonatal respiratory morbidities, other neonatal respiratory morbidities, other neonatal complications, or maternal complications were also evaluated as exploratory outcomes.

None of the 1,620 neonates (818 in the intervention group and 802 in the placebo group) died within 72 hours after birth. Severe neonatal respiratory morbidity occurred in 99 neonates (6.1 percent), with the incidence being lower in the betamethasone group than in the placebo group (4.8 percent vs 7.5 percent; relative risk [RR], 0.64, 95 percent confidence interval [CI], 0.42–0.98).

For the exploratory outcomes, the betamethasone group were less likely to have continuous positive airway pressure use for ≥2 hours (RR, 0.58, 95 percent CI, 0.35–0.95) and transient tachypnoea of the newborn (RR, 0.47, 95 percent CI, 0.25-0.89) compared with the placebo group.

The risk of the primary outcome and mild respiratory morbidities was reduced only in neonates delivered between ≥12 hours and <7 days after the first betamethasone administration.

The risk of neonatal hypoglycaemia was greater in the betamethasone vs the placebo group (15.6 percent vs 11.7 percent; RR, 1.33, 95 percent CI, 1.01–1.75), whereas the risk of neonatal sepsis or maternal chorioamnionitis did not differ between the two groups.

Overall, the findings may serve as a valuable reference in clinical management of twin pregnancies at risk of late preterm delivery, according to researchers.