SUN-521 Sensitivity of HbA1c tested in the first trimester in prediction of gestational diabetes mellitus among Saudi pregnant women

Abstract Disclosure: A.H. Alsaeed: Eli Lilly & Company, AstraZeneca, Sanofi-Aventis. N. Alkhaldi: None. A. Al-Muteb: None. A. Alwin robert: None. Background: HbA1c is one of the tools used to diagnose diabetes mellitus. There is still debate about the cut off value of HbA1c to label pregnant women screened in the first trimester as suffering from gestation diabetes mellitus (GDM). Aim of the study: to evaluate the sensitivity of HbA1c tested in first trimester in predicting the GDM. Method: Pregnant women who underwent a 75 gm OGTT between 24-28 weeks of gestation and had FBS, and HbA1c measured in the first trimester between January till December 2022 were retrospectively reviewed. Women with pre-existing diabetes, HbA1c ≥ 6.5%, FBS≥7 mmol/L or on anti-diabetic medication were excluded from the study. The main outcome is to find out the correlation between the first trimester HbA1c levels and OGTT at 24-28 weeks’ gestation for the diagnosis of GDM. Results: Data of 552 women who met the inclusion criteria were analyzed. A total of 183 (33%) of woman’s had GDM diagnoed by OGTT at 24-28 weeks of gestation. A 107 (19.4%) individuals of the total cohort had abnormal HbA1c at the prediabetes range at the first trimester, 59 women(54%) had proven GDM,while 46 women(46%) had falsely high HbA1c in the first trimester with normal OGTT. A multivariante analysis showed HbA1c ≥6.1 ± 0.32% (p=0.001), and FBS≥ 5.39 ± 1.47mmol/L were stastically significant in predicting future GDM. Conclusion: First trimester HbA1c may aid in early identification of at-risk women. A prospective well-designed study might be needed to elaborate factors affecting using such tool for early detection of GDM in Saudi population . Presentation: Sunday, July 13, 2025