The importance of fasting blood glucose in screening for gestational diabetes

Objective: To determine how well an isolated abnormal fasting blood glucose (FBG) value on the 1-step, 75-g, 2-hour glucose tolerance test (GTT) indicates significant gestational diabetes (GDM). Methods: Retrospective cohort study, January 2011 to May 2012. Patients diagnosed by the 1-step method were assigned by their abnormal results to the isolated fasting (FBG), isolated 1-hour (1HBG), isolated 2-hour (2HBG), or multiple-value (≥2BG) group. Characteristics and outcomes were compared using ANOVA, Kruskal - Wallis, and Chi-squared tests. Results: 324 patients were included. Compared to other groups, the FBG group (N = 23) had the highest incidence of requiring medical therapy (78.26%), mean body mass index (29.40 ± 6.20 kg/m²), and percentage of Black plus Hispanic women (60.87%). Conclusions: Seven percent of women were diagnosed with GDM by an isolated abnormal fasting BG and have significant disease. This group should not be missed; therefore, fasting BG should be integrated into all GDM screening.