881 Practice patterns in the administration of late preterm antenatal corticosteroids

Abstract

Given the unpredictable nature of preterm birth (PTB) and the short-term impact of antenatal corticosteroids (ACS) on neonatal outcomes, optimal timing of ACS administration (2-7 days from expected birth) remains challenging. We set out to evaluate the likelihood of optimal timing of ACS administration in the late preterm period, and whether this differs based on indication for ACS administration. Retrospective cohort of all singletons that received ACS in the late preterm period (34 0/7-36 6/7 weeks) and delivered within a large health system between November 2017 and March 2020. Women who received ACS prior to the late preterm period, major fetal structural malformations, and cases with missing data were excluded. Cases were stratified based on the indication for ACS administration i.e. anticipated spontaneous PTB (sPTB) or medically indicated PTB. The primary outcome was delivery within 2-7 days of ACS administration. Secondary outcomes included time interval from ACS administration to delivery, as well as delivery within 2 and > 7 days of ACS administration. Multivariate logistic regression was performed to evaluate factors associated with optimal timing, while adjusting for potential confounders. Of the 1,238 patients included, 656 (53%) received one of two doses of ACS. Baseline characteristics compared between the two groups are displayed in Table 1. Delivery within the optimal time interval was more common (23.4% vs 5%, P = <0.001; Table 2), and more likely (adjusted OR 5.88, 95% CI 4-9.09) in women at risk for medically indicated PTB compared to anticipated sPTB. Furthermore, women with anticipated sPTB had a shorter time interval from ACS administration to delivery (10.7 hrs vs. 49.71 hrs, P = <0.001). Regardless of the indication, the likelihood of optimally timed ACS in the late preterm period is low. Nevertheless, our data suggest that current practice patterns of ACS administration in the late preterm period are more likely to benefit women at risk for medically indicated PTB compared to those at risk for sPTB.View Large Image Figure ViewerDownload Hi-res image Download (PPT)