Late-preterm antenatal corticosteroid treatment in twin pregnancies and newborn morbidity

Newborn morbidity is not reduced in twin pregnancies through late-preterm administration of antenatal corticosteroid treatment, according to a recent study published in JAMA Network Open.

A significant worldwide increase in twin pregnancy incidence has been observed over the past 4 decades, with high rates of preterm birth reported among twin pregnancies. About 70% of twin pregnancies comprise of twins born in the late-preterm period, defined as 34 weeks and 0 days to 36 weeks and 6 days of gestation.

Women at risk of preterm birth often receive antenatal corticosteroids from 24 weeks and 0 days to33 weeks and 6 days of gestation to decrease infant morbidity and mortality risks. Use of antenatal corticosteroids is also approved for use in the late preterm period among women at risk of imminent birth. However, data on twins in the late-preterm period is lacking.

Investigators conducted a retrospective cohort study to evaluate the association between late-preterm antenatal corticosteroid treatment administration and neonatal outcomes among twin pregnancies. Twin pregnancies delivered at the Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China between February 1, 2013, and September 30, 2020, were included in the analysis.

Data on maternal characteristics, antenatal corticosteroid treatment, pregnancy outcomes, and neonatal outcomes was obtained from electronic medical health records. Eligibility criteria included prenatal medical record at the hospital and receipt of routine prenatal care from hospital until delivery.

Exclusion criteria included delivery under 34 weeks’ gestation, intrauterine death of 1 fetus, major congenital abnormality or fetal chromosomal abnormality, monochorionic monoamniotic twins, chorioamnionitis or maternal fever, complications unique to monochorionic twins, missing outcomes, and antenatal corticosteroid treatment before 34 weeks’ gestation.

The administration of 1 or more dose of antenatal corticosteroids from 34 weeks and 0 days to 36 weeks and 6 days of gestation in patients at high risk of delivery in late-preterm was defined as the exposure of the analysis. Antenatal corticosteroid treatment administration included 4 intramuscular doses of 5 mg of dexamethasone, administered every 12 hours.

Composite neonatal respiratory morbidity was the primary outcome of the analysis, defined as at least 1 of the following occurrences in either neonate: surfactant administration, respiratory distress syndrome, mechanical ventilation, and neonatal death. Secondary outcomes included continuous positive airway pressure (CPAP) use and CPAP use for over 2 days.

There were 1974 patients with twin pregnancies included in the analysis, 15.3% of which received late-preterm antenatal corticosteroid treatment and 84.7% of which did not receive antenatal corticosteroid treatment. Delivery before 37 weeks’ gestation was reported in 89.4% of the antenatal corticosteroid treatment group compared to 42.5% of the control group.

The risk of composite neonatal respiratory morbidity did not significantly differ between the 2 groups, with a weighted odds ratio of 1.27. Secondary outcomes such as CPAP use also did not significantly differ based on antenatal corticosteroid treatment use.

These results did not indicate an association between antenatal corticosteroid treatment in late-preterm and reduced neonatal morbidity risk among twin pregnancies. Investigators recommended future well-designed prospective studies evaluating the potential association.

Reference

Zhu J, Zhao Y, An P, et al. Antenatal corticosteroid treatment during the late-preterm period and neonatal outcomes for twin pregnancies. JAMA Netw Open. 2023;6(11):e2343781. doi:10.1001/jamanetworkopen.2023.43781