(347) The Utility of Hemoglobin A1c in the First Trimester for Detection of Gestational Diabetes

Of 476 women included, 441 (92.6%) were in Group 1 and 35 (7.4%) in Group 2. GDM prevalence for the full cohort was 17.8% (85/476). Of these, 13.8% (61/441) in Group 1 were diagnosed with GDM, and 68.5% (24/35) were diagnosed with GDM in Group 2 (p < 0.00001). The PPV of HbA1c 5.7%-6.4% was 62.8% for early GDM HBA1c had a good ability to predict GDM with an area under the ROC curve of 0.75 (Figure 1), but an optimal cut off value was not identified. Among known risk factors, HbA1c 5.7%-6.4% was the best predictor for GDM (odds ratio [OR] 14.12; 95% confidence interval [CI] 6.41, 31.12).  Postpartum hemorrhage (PPH) was significantly higher in women with 5.7%-6.4% HBA1c (adjusted OR 9.93; 95% CI 2.62, 37.6). Adverse neonatal outcomes did not differ significantly among the groups.  

Conclusion:

In a clinical setting with high prevalence of GDM, HBA1c in the first trimester is an acceptable screening tool and a better predictor compared with clinical risk factors. Elevated pre-diabetes HBA1c was also associated with PPH.