Potential missed opportunities for antenatal corticosteroid exposure and outcomes among periviable births: observational cohort study.

OBJECTIVE: Test the hypothesis potential missed opportunities for antenatal corticosteroids increase as gestational age decreases and are associated with adverse outcomes. DESIGN: Observational cohort study. SETTING: 24 US centers in the Neonatal Research Network. POPULATION: Actively treated infants 22-25 weeks' gestation and birth weight 401-1000 grams, without major birth defects, born 2006-2018. METHODS: Potential missed opportunity was defined as no antenatal corticosteroids but did have prenatal antibiotics, and/or magnesium sulfate, and/or prolonged rupture of membranes. Poisson regression models adjusted for baseline characteristics. MAIN OUTCOME MEASURES: Antenatal corticosteroid exposure, mortality, and severe intracranial hemorrhage or periventricular leukomalacia. RESULTS: 6966 (87.5%) were exposed to antenatal corticosteroids, 454 (5.7%) had no exposure but potential missed opportunities for antenatal corticosteroid exposure, and 537 (6.7%) had no exposure and no evidence of potential missed opportunities. Compared with infants born at 25 weeks, potential missed opportunities for antenatal corticosteroid exposure were more likely at 22 weeks (adjusted relative risk (aRR) [95% CI] 11.06 [7.52-16.27]) and 23 weeks (3.24 [2.44-4.29]) but did not differ at 24 weeks (1.08 [0.82-1.42]). Potential missed opportunities for antenatal corticosteroids decreased over time at 22-23 weeks' gestation. Antenatal corticosteroid exposed infants had lower risk of death (31.0% vs 54.8%; 0.77 [0.70-0.84]) and survivors had lower risk of severe brain injury (25.0% v 44.5%; 0.64 [0.55-0.73]) compared with infants with potential missed opportunities. CONCLUSION: Potential missed opportunities for antenatal corticosteroid exposure increased with decreasing gestational age and were associated with higher rates of death and severe brain injury among actively treated periviable births.