2155-P: Adverse Pregnancy Outcomes with Early vs. Late Gestational Diabetes Mellitus

Introduction and Objective: Current U.S. guidelines no longer recommend screening for gestational diabetes mellitus (GDM) before 24 weeks gestation due to insufficient evidence that early diagnosis improves adverse pregnancy outcomes (APOs). Our study evaluated if an early versus late (≥24 weeks) GDM diagnosis was associated with differences in APO risk. Methods: This was a retrospective cohort study of individuals with GDM diagnosis at a single tertiary care center from 2018-2021, where early GDM screening was offered per ACOG guidance. The exposure was early (<24 weeks) versus late (≥24 weeks) GDM diagnosis. APO’s included cesarean delivery, hypertensive disorders of pregnancy (HDP), preterm birth (PTB), small or large for-gestational-age (SGA/LGA), and NICU admission. Inverse probability of treatment weighting was used to address confounding adjusting for parity, BMI, and GDM pharmacotherapy. Results: Among 1,171 individuals with GDM, 164 (14%) were diagnosed early. Those with early GDM were more likely to be older, have higher BMI, identify as non-Hispanic White, have greater dysglycemia at screening, and require pharmacotherapy (all p<0.05). Early GDM was associated with higher rates of cesarean delivery (43.9% vs. 35.5%), LGA (20.4% vs. 14.1%), and PTB (18.3% vs. 11.3%); however, on adjusted analysis, the risk of APOs were similar between groups. Conclusion: After adjustment, early GDM was not associated with increased APO risk compared with late GDM, supporting current U.S. guidelines.