Performance and the Optimal Cut-Off Value of First-Trimester Fasting Plasma Glucose To Identify Gestational Diabetes Mellitus: A Retrospective Study From Southern China

Abstract Purpose Previous studies have suggested that first-trimester fasting plasma glucose (FPG) is associated with gestational diabetes mellitus (GDM) and is a predictor of GDM. The aim of the present study was to explore whether first-trimester FPG levels can be used as a screening and diagnostic test for GDM in pregnant women. Methods This retrospective study included pregnant women who had their first-trimester FPG recorded at 9-13 +6 weeks and underwent screening for GDM using the 2-hour 75 g oral glucose tolerance test (OGTT) between 24th and 28th gestational weeks. The cut-off values were calculated using a receiver operating characteristic (ROC) curve. Results The medical records of 28,030 pregnant women were analysed, and 4,669 (16.66%) of them were diagnosed with GDM. The mean first-trimester FPG was 4.62 ± 0.37 mmol/L. The total trend in the optimal cut-off value of first-trimester FPG in pregnant women was 4.735 mmol/L, with a sensitivity of 49%, a specificity of 67.6% and AUC of 0.608 (95% CI: 0.598-0.617, p༜0.001). Moreover, as the maternal age increased, the optimal cut-off values increased, respectively. The results suggest that first-trimester FPG can be considered a marker for identifying pregnant women with GDM. Conclusion The level of first-trimester FPG increased slightly with maternal age and, as maternal age increased, the optimal cut-off values increased, especially after age 30. The first-trimester FPG should be considered a screening marker when diagnosing GDM in pregnant women.