778 Latency of late preterm steroid administration to delivery and risk of neonatal hypoglycemia

Abstract

Late preterm antenatal corticosteroid (ACS) administration has been associated with an increased risk of neonatal hypoglycemia. The mechanism is thought to be secondary to transient fetal hyperinsulinemia, which may be more likely if delivery occurs during peak maternal ACS levels. The aim of this study was to investigate if there is a latency interval between ACS administration and delivery that places neonates at greatest risk of hypoglycemia. Retrospective case control study of pregnant women who received ACS between 34 0/7 to 36 6/7 weeks’ gestation from 2016–2019. Controls were women who did not receive ACS matched according to gestational age week at delivery, diabetes, twins, and maternal weight from 2010-2015. Latency periods from initial steroid administration to delivery were defined in intervals of 12 hours until ≥ 72 hours. The primary outcome was neonatal hypoglycemia, defined as ≤ 40 mg/dL. Poisson regression was used to generate an adjusted relative risk (aRR) for hypoglycemia for each latency period adjusting for confounders. 1300 women were included in the analysis (650 cases and 650 controls). Women who received ACS were slightly older (p=.025) and more likely to be of White race (p=.002), but otherwise were well matched on pregnancy complications and baseline demographics (Table 1). In women receiving ACS, most delivered within 0-11 hours from steroid administration (27.4%) or ≥ 72 hours from administration (35.9%). Latency time intervals of 12-23 hours, 24-35 hours, and 35-47 hours were significant for frequency of hypoglycemia when compared to controls after adjustment (Table 2). Hypertensive disorders were the most common ACS indication (42.9%) in women who delivered during the highest risk latency window for neonatal hypoglycemia. In the late preterm period, the greatest risk of neonatal hypoglycemia is a latency period of 12-47 hours between steroid administration and delivery. The risk of ACS may outweigh the benefit in patients who deliver in this window.View Large Image Figure ViewerDownload Hi-res image Download (PPT)