Maternal Race and Ethnicity and Risk of Cesarean Delivery in Large for Gestational Age Pregnancies [A343

Abstract

INTRODUCTION: To compare the rate of Cesarean delivery in pregnancies complicated by large for gestational age (LGA) fetuses in non-Hispanic White (NHW) patients to patients who identified as non-White and/or Hispanic. METHODS: This secondary analysis of a large institutional review board-approved retrospective cohort study included deliveries of live singleton fetuses at a tertiary-care hospital from 2007-2019. Deliveries of LGA fetuses, defined by an estimated fetal weight at 90th percentile or greater for gestational age on third trimester ultrasound, were identified and maternal characteristics and mode of delivery extracted. The primary outcome was Cesarean delivery for any indication. RESULTS: Of 3,593 eligible patients, 1,314 self-identified as NHW and 1,913 as non-White and/or Hispanic. NHW patients were older, taller, more likely to have type 1 diabetes and/or commercial insurance, and less likely to have gestational diabetes (P<.01 for all). Rates of type 2 diabetes were similar between groups (P=0.41). Overall, 48.1% of LGA pregnancies delivered by Cesarean, with a higher rate of Cesarean among NHW patients (50.88% vs. 45.32%; relative risk [RR] 1.11; 95% CI, 1.05–1.18). This relationship persisted after adjusting for differences in maternal age (adjusted RR [aRR] 1.10; 95% CI, 1.03–1.17), height (aRR 1.16; 95% CI, 1.07–1.26), payor status (aRR 1.08; 95% CI, 1.003–1.16]), and prevalence of diabetes (aRR 1.13; 95% CI, 1.05–1.22]) between groups. CONCLUSION: Among LGA pregnancies, NHW patients were more likely to undergo Cesarean delivery than patients who identified as non-White and/or Hispanic. This stands in contrast to existing data showing that NHW patients are less likely to deliver by Cesarean overall.