Abstract: Objective To evaluate the incidence of gestational diabetes mellitus（GDM）in Binhu district of Hefei,we investigated the composition ratio within different types of GDM in each groups,and explored the difference of diagnosis of GDM in oral glucose tolerance test（OGTT）at different time points. Methods From January 2016 to September 2019,22 881 pregnant women who underwent routine obstetric examination in Binhu Hospital of Hefei were screened,and OGTT test had been performed in their 24~28 weeks of gestation. In order to evaluate the value of abnormal blood glucose at any time point and any two time points for the diagnosis of GDM,the area under the different ROC curves had been compared. Results According to the new IADPSD standard,the overall incidence of GDM in Binhu area of Hefei was 24.74%. With the increasing age,the incidence of GDM increased significantly. There were statistically differences between groups. The incidence of GDM in women aged ≥35 years was 40.05%,while the incidence was 15.40% in women aged <25 years. The distribution of patients with different types of GDM in each group obviously different. The area under the curves （AUC） of fasting blood glucose in diagnosis of GDM at any one point was significantly greater than that at any two points （Z=5.502,P<0.000 1）. The AUC of 1 h （Z=35.44,P<0.000 1）and 2 h（Z=31.18,P<0.000 1） in diagnosis of GDM at any two points was significantly greater than that any one point. Conclusion the incidence of GDM in Binhu district of Hefei is relatively high. The sensitivity and specificity of abnormal fasting blood glucose combined with 1 h or 2 h better than that of single 1h or 2h abnormal blood glucose. Same as above,among pregnant women aged ≥35 years,the AUC of fasting blood glucose in diagnosis of GDM at any one point was also statistically different from that at any two point （Z=2.064,P=0.039）

Key words: Gestational Diabetes Mellitus （GDM）, Oral Glucose Tolerance Test, ROC curve