187-OR: Randomized Clinical Trial of the IADPSG vs. Carpenter Coustan Criteria for Diagnosis of Gestational Diabetes Mellitus

Abstract

No clinical consensus regarding the optimal diagnostic approach for gestational diabetes mellitus (GDM) exists. Participants were randomized to two GDM testing criteria following a blinded non-fasting 50g glucose challenge test (GCT): Carpenter Coustan (CC) or IADPSG. GDM was diagnosed in the CC arm if the 50g GCT was > 135 mg/dL and the fasting 100g OGTT had 2 or more abnormal values. GDM was diagnosed in the IADPSG arm if the fasting 75g OGTT had one or more abnormal values; the 50g GCT was ignored for diagnosis. Participants and providers were informed whether GDM was present but blinded to all test results and which criteria were used for diagnosis. Treatment for GDM occurred per routine clinical care. We hypothesized lower rates of LGA favoring the IADPSG arm, both overall and after restricting to women without GDM. From 2015-2019, 921 women were enrolled and randomized (CC=460; IADPSG-461); however, delivery records were available for only 878 women. Baseline characteristics were similar between groups. While GDM diagnosis (14.4% vs. 4.5%, p<0.001) and diabetes medication use (9.3 v 2.4%; p<0.001) were more common in the IADPSG arm, there were no differences in LGA, either overall (OR=0.90, 95% CI 0.51-1.58) or restricting to women without GDM (OR=0.86, 95% CI 0.47-1.57). Disclosure C.M. Scifres: None. K. Abebe: None. H. Simhan: None. P. Catalano: None. T. Costacou: None. D.M. Comer: None. S.R. Orris: None. K. Ly: None. A. Decker: None. D. Mendez: None. E. Davis: None. Funding National Institutes of Health (1R01HD079647)