1237-P: IADPSG Criteria of Gestational Diabetes—Is It Optimized across Ethnicities?

Introduction: Gestational Diabetes Mellitus (GDM) affects ~20% of Asian pregnancies, presenting substantial maternofetal risks. Despite the widespread adoption of International Association of Diabetes and Pregnancy Study Groups (IADPSG) GDM criteria, ethnic variations in insulin regulation, evidenced by unique oral glucose tolerance test (OGTT) profiles, have been noted. Our study investigates the relationship between three Asian ethnic groups (Chinese, Malay, Indian) and distinct OGTT phenotypes in GDM diagnosis within a multi-ethnic cohort.

Method: A retrospective review of 3,027 patients without pre-existing diabetes from KK Women's and Children's Hospital (2019) was conducted. GDM was diagnosed using the IADPSG criteria at 24-28 weeks. Adjusted multivariate analyses using a multinomial logistic regression with robust variances were used to estimate the relative risk ratios (RRR) between the ethnic-specific relative risk ratios and OGTT phenotypes, accounting for maternal age, parity, and first-trimester body mass index as potential confounders.

Results: GDM prevalence was highest among Indians (21.5%), followed by Chinese (18.4%) and Malays (14.2%). Compared to Malays, the Chinese and Indians were significantly associated with a higher risk of surpassing the OGTT threshold at 0h with a RRR of 2.33 (95% CI: 1.01-5.38, p<0.05), and RRR of 3.05 (95% CI: 1.23-7.56, p<0.05 respectively, with Indians being at the highest risk. Only the Chinese ethnic group was associated with an RRR of 2.88 (95% CI: 1.51-5.47, p<0.01) for surpassing the OGTT threshold at 2h, compared to the Malays.

Conclusion: Indians were at higher risk of exceeding the 0h-only OGTT threshold, while Chinese were at higher risk of surpassing both the 0h-only and 2h-only OGTT thresholds. These patterns highlight inherent ethnic variations in glucose metabolism, underpinning the diverse OGTT phenotypes observed. These metabolic distinctions call for the development of an ethnic-sensitive diagnostic criteria.