528: Evaluation of early screening for Gestational Diabetes Mellitus (GDM) with standard HbA1c

Abstract

Diabetes mellitus (DM) is associated with adverse pregnancy outcomes and early detection allows for timely management of the disease. Early DM screening is currently recommended for pregnant women who are considered high risk via a 1-hour glucose challenge test (1h GCT). This test is often bothersome for women as it is time-consuming and may induce gastrointestinal distress. Hemoglobin A1c (A1c) is a fast and reliable method of assessing long term glycemic control. We sought to examine the correlation between hemoglobin A1c (A1c) and 1h GCT for DM screening in early pregnancy This was a retrospective cohort study of pregnant women who were high-risk for DM that underwent early A1c and 1h GCT between October 2017 and July 2019. We defined ‘high-risk’ as women that met the criteria for early testing based on the screening strategy in American College of Obstetricians and Gynecologists practice bulletin # 180. Three-hour glucose tolerance test (3h GTT) data was also collected if the 1h GCT was abnormal (>135 mg/dL). DM was diagnosed if the A1c was 6.5% or higher. Pearson correlation coefficient was calculated to investigate the relationship between early A1c and 1h GCT A total of 115 patients were included with mean age of 30.4 and mean BMI of 36.8 kg/m2. Median gestational age was 8.9 weeks at A1c draw and 13.8 weeks at 1h GCT draw. Two (1.7%) women were diagnosed with DM based on an early A1c. Four of 20 women (20.0%) with early A1c of 5.7-6.4% and 2 of 93 (2.2%) with A1c< 5.7% had an early diagnosis of DM. A significant positive correlation between A1c and early 1h GCT result was detected (Pearson correlation coefficient=0.55, P< 0.01). A1c significantly predicts the risk of early 1h GCT with AUC=0.75 (95%CI: 0.63,0.86) and the risk of DM with AUC=0.91 (95%CI: 0.83,0.99). An early A1c of 5.3% or less (61.7% of patients) had a 100% negative predictive value for DM A1c correlates with 1h GCT for the early screening of gestational DM. Our findings suggest that women with an early A1c ≤ 5.3% in a similar-risk population could potentially forego further testingView Large Image Figure ViewerDownload Hi-res image Download (PPT)