(639) Two antenatal corticosteroid doses are necessary to decrease neonatal mortality in VLBW infants

To investigate the impact of the number of antenatal corticosteroid (ACS) administrations on short- and long-term outcomes in very-low-birth-weight (VLBW, 400–1,500 g) infants using a large multicenter cohort from Japan.


Study Design:

This secondary analysis used data of 3,317 infants from 40 perinatal centers nationwide, originally compiled for a study by Nishida et al. in 2024. After excluding twins, major congenital or chromosomal anomalies, gestational age ≥34 weeks, unknown ACS use, placenta previa, and placental abruption, 1,866 infants remained. Outcomes included NICU mortality, short-term morbidities—respiratory distress syndrome (RDS), patent ductus arteriosus (PDA), sepsis, chronic lung disease (CLD), intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC)—and neurological impairment at three years. Univariate analyses identified perinatal factors associated with mortality, which were adjusted in multivariate logistic regression assessing the association between ACS doses and outcomes.


Results:
NICU mortality was significantly associated with gestational age, birth weight, premature rupture of membranes, clinical chorioamnionitis, ACS use, and pregnancy-induced hypertension, but not with umbilical artery pH, non-reassuring fetal status, gestational diabetes, maternal age, or infant sex. A single ACS dose significantly reduced short-term morbidities except NEC. However, mortality did not differ between no ACS and a single dose, whereas two doses were required for a significant mortality reduction. No association was observed between ACS doses and neurological impairment at three years.

Conclusion:

In VLBW infants, one ACS dose reduced neonatal complications, while two were necessary to lower mortality. ACS did not improve long-term neurodevelopment, possibly reflecting environmental influences. These findings may help balance effective ACS use with minimizing unnecessary exposure.