958 The impact of time interval from late preterm corticosteroid administration to delivery on neonatal outcomes

Abstract

While administration of antenatal corticosteroids (ACS) has been shown to decrease newborn respiratory morbidity when given to women at risk for late preterm birth (PTB), the optimal time interval from ACS to delivery remains unknown. We investigated the association of the time interval from ACS to delivery and adverse neonatal outcomes. Retrospective cohort of all newborns from singleton pregnancies that were exposed to ACS in the late preterm period (34 0/7-36 6/7 weeks) within a large health system (November 2017- March 2020). Newborns exposed to ACS prior to the late preterm period, major fetal structural malformations and confirmed chromosomal disorders were excluded. Cases were stratified based on time interval from ACS administration to delivery: <2, 2-7, and >7 days. The rates of transient tachypnea of the newborn (TTN), respiratory distress syndrome (RDS), and hypoglycemia were compared among the three groups. Multivariate logistic regression was performed to evaluate the association of time interval with neonatal outcomes, while adjusting for potential confounders. 1,248 newborns comprised the study cohort. Baseline characteristics compared among the three groups are displayed in Table 1. After adjusting for number of ACS doses (1 or 2) and gestational age at delivery, we detected an increased risk of TTN associated with delivery <2 days (aOR 3.80, 95% CI 1.42-10.18) and >7 days (aOR 3.39, 95% CI 1.12-10.27) of ACS administration (Table 2). The risk of hypoglycemia was highest in the delivery <2 days group (aOR 3.3, 95% CI 2.01-5.41) and decreased as time interval from ACS to delivery increased (Table 2). Adverse neonatal outcomes such as TTN and hypoglycemia are more common when late PTB occurs <2 days after ACS administration. Moreover, late PTB >7 days after ACS administration is associated with an increased risk of TTN, but a decreased risk of hypoglycemia. Understanding the impact of ACS timing on neonatal outcomes is essential in caring for patients at risk for late PTB.View Large Image Figure ViewerDownload Hi-res image Download (PPT)