Antenatal Corticosteroids for Small for Gestational Age in Late Preterm Newborns.

BACKGROUND: 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.

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

METHODS: 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.

RESULTS: 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).

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