The examination methods and diagnostic criteria for gestational diabetes are as follows: 1. For the first prenatal checkup, all pregnant women should be evaluated for diabetes risk factors as well as fasting blood glucose during the first maternity checkup in early pregnancy. If fasting blood glucose >7.0mmol/L, or glycosylated hemoglobin >6.5%, or random blood glucose ≥11.1mmol/L and diabetic symptoms, the diagnosis of overt diabetes mellitus combined with pregnancy can be made; if fasting blood glucose <5.1mmol/L and 75g glucose tolerance test is done at 24-26 weeks, fasting blood glucose ≥5.1mmol/L but <7.0mmol/L, the Diagnosis of gestational diabetes. 2. 24-28 weeks glucose tolerance test examination for pregnant women, fasting 8-14 hours, taking 75g glucose plus 300ml boiled water, drinking within 5 minutes, collecting fasting, 1 hour and 2 hours elbow venous blood after taking glucose. 3 blood glucose values should be lower than 5.1mmol/L, 10.0mmol/L, 8.5mmol/L respectively. any one The diagnosis of gestational diabetes is made when any of the blood glucose values meet or exceed the above criteria. If fasting blood glucose is ≥7.0mmol/L, the diagnosis of overt diabetes mellitus combined with pregnancy is made. If a pregnant woman has risk factors for gestational diabetes and her first glucose tolerance test result is normal, the glucose tolerance test can be repeated in late pregnancy if necessary.