Antenatal Corticosteroids for Small for Gestational Age in Late Preterm Newborns

The administration of antenatal corticosteroids (ACS) is standard practice for management of threatened preterm birth. Its benefit, especially in small for gestational age (SGA) late preterm, is unclear.

To evaluate the impact of ACS on perinatal outcome of late preterm SGA neonates.

We conducted a retrospective cohort study of all women carrying a singleton gestation who had late preterm delivery (34-36 gestational weeks) of SGA neonates at a single tertiary university-affiliated medical center (July 2012-December 2017). Exclusion criteria included termination of pregnancy, intrauterine fetal death, and birth weight ≥ 10th percentile. Outcomes were compared between ACS and non-ACS treatment prior to delivery. Neonatal composite outcome included neonatal intensive care unit (NICU) admission, respiratory distress syndrome, mechanical ventilation, and transient tachypnea.

Overall, 228 women met inclusion criteria; 102 (44.7%) received ACS and 126 did not (55.3%). Median birth weight among the non-ACS group was significantly higher (1896.0 vs. 1755.5 grams P < 0.001). Rates of NICU and jaundice requiring phototherapy were higher among the ACS group (53.92% vs. 31.74%, P = 0.01; 12.74% vs. 5.55%, P = 0.05, respectively). Composite neonatal outcome was significantly higher among the ACS group (53.92% vs. 32.53%, odds ratio [OR] 2.42, 95% confidence interval [95%CI] 1.41-4.15, P = 0.01). After adjustment for potential confounders, this association remained significant (OR 2.15, 95%CI 1.23-3.78, P = 0.007).

ACS given during pregnancy did not improve respiratory outcome for SGA late preterm neonates. ACS may be associated with a worse outcome.