Prediction of gestational diabetes mellitus in the first trimester by fasting plasma glucose which cutoff is better?

Objective: We aimed to predict subsequent gestational diabetes mellitus (GDM) by fasting plasma glucose (FPG) in the first trimester. Methods: Healthy pregnant women who were screened for GDM at 24-28 gestational weeks and had FPG levels calculated during their first antenatal visit and less than 14 gestational weeks were included in this study. Results: Of the 2605 women who were recruited for the study, 245 (9.4%) were diagnosed with GDM at weeks 24-28. The diagnostic accuracy for FPG predicting GDM was 66.5, 78.4, and 88.2 for the cutoff values of 87.5 mg/dl, 92 mg/dl, and 99.5 mg/dl, respectively. Conclusions: FPG values which are within the normoglycaemic range constitute an independent risk factor for the development of GDM. The threshold for gestational diabetes diagnosis must be revised.