Antenatal Corticosteroids and Neonatal Outcomes Among Patients With Twin Gestations at Risk for Late Preterm Birth

OBJECTIVE: To determine whether administration of antenatal corticosteroids to patients with twin gestations at risk for late preterm delivery is associated with reduced risk for neonatal respiratory morbidity compared with unexposed twins. METHODS: This was a multicenter, retrospective cohort study in a large, urban health network (2013–2022) of patients with twin gestations at risk for preterm delivery between 34 0/7 and 36 6/7 weeks of gestation. Patients were excluded if they received antenatal corticosteroids before 34 weeks of gestation or had pregestational diabetes, single-twin death before 34 weeks, or oral steroid exposure during pregnancy. Neonates were excluded if they had major congenital anomalies. The primary outcome was a composite of neonatal respiratory morbidity requiring respiratory support within 72 hours of birth, including continuous positive airway pressure (CPAP) or high-flow nasal cannula for 2 hours or more, supplemental oxygen of 30% for 2 hours or more, extracorporeal membrane oxygenation, mechanical ventilation, and fetal or neonatal death. Secondary outcomes included neonatal hypoglycemia and indications for neonatal intensive care unit (NICU) admission. Adjusted and unadjusted relative risks with 95% CIs were calculated. RESULTS: During the study period, 366 twin gestations and 722 patient–neonate dyads were included: 162 gestations (321 neonates) in the exposed group and 204 (401 neonates) in the unexposed group. There was no difference in the composite outcome of respiratory morbidity in those exposed to antenatal corticosteroids (23.4% vs 20.4%, P =.40, adjusted relative risk [RR] 1.00, 95% CI, 0.71–1.42). The composite was driven mostly by rates of CPAP use (21.2% vs 18.5%, P =.41, adjusted RR 1.05, 95% CI, 0.73–1.53) and high-flow nasal cannula use (6.2% vs 2.2%, P =.02, RR 2.77, 95% CI, 1.16–6.66). Antenatal corticosteroid exposure was associated with a lower risk of need for supplemental oxygen (0.6% vs 3.5%, P =.02, RR 0.18, 95% CI, 0.04–0.79) and mechanical ventilation (0.6% vs 3.2%, P =.03, RR 0.19, 95% CI, 0.04–0.87). Although antenatal corticosteroids exposure was not associated with higher rates of hypoglycemia (44.2% vs 41.7%, P =.57, adjusted RR 0.99, 95% CI, 0.82–1.19), exposure was associated with a higher risk of having hypoglycemia as the only indication for NICU admission (10.3% vs 5.2%, P =.03, RR 1.96, 95% CI, 1.07–3.59). CONCLUSION: In a large, multicenter, network-wide retrospective cohort study of patients with twin gestations at risk for late preterm birth, antenatal corticosteroid use was not associated with a decrease in overall respiratory morbidity but was associated with a decreased risk of need for supplemental oxygen and mechanical ventilation, as well as a higher risk of NICU admission for hypoglycemia. These results underscore the ongoing need to elucidate the risks and benefits of late preterm antenatal corticosteroids for patients with twin gestations at risk for late preterm birth.