The association between antenatal corticosteroids exposure and postnatal growth in infants born between 23 and 29 weeks of gestation.

Objective: To assess the association between antenatal corticosteroids exposure and postnatal growth in infants born at 23-29 weeks' gestation.

Study Design: This retrospective study used data from the Pediatrix Clinical Data Warehouse. Maternal-infant dyads from 2018 to 2020 were included. Inverse propensity weighting (IPW) was applied to balance pre-treatment confounders. Primary outcomes included postnatal weight, length, and head circumference growth trajectory percentiles.

Result: The unadjusted cohort consisted of 11,912 dyads. After IPW adjustment, there were 23,231 dyads. Exposed infants showed higher postnatal trajectory percentiles for weight (by 3.4%), length (by 1.8%), and head circumference (by 2.5%) when compared to non-exposed infants. The positive association between antenatal corticosteroids and postnatal growth was only observed in infants not exposed to preeclampsia/eclampsia/HELLP syndrome or without fetal growth restriction.

Conclusion: Antenatal corticosteroids exposure is associated with better postnatal growth. The study is limited by its retrospective nature.