Gestational Age-Specific Effects of Antenatal Corticosteroids on Early Physiologic Vulnerability and Neonatal Outcomes

Objective To evaluate gestational age (GA)-specific associations between antenatal corticosteroid (ACS) exposure and early physiologic vulnerability and neonatal outcomes in preterm infants. Study Design This retrospective cohort study used Korean Neonatal Network data and included infants born between 2013 and 2021 with birth weight < 1 500 g or GA < 32 weeks. ACS exposure was categorized as complete, incomplete, or none. Multivariable logistic regression estimated adjusted odds ratios, with GA-stratified analyses and a prespecified subgroup of infants born at < 25 weeks. Results ACS exposure was associated with lower delivery room resuscitation intensity, reduced risk of severe intraventricular hemorrhage, and decreased mortality, with strongest associations observed before 32 weeks. In infants born at < 25 weeks, any ACS exposure was associated with greater physiologic stability and improved survival compared with no ACS exposure. Conclusions ACS exposure was associated with improved physiologic stability and survival in preterm infants, with benefits greater at lower GAs.