In 2010, the International Association of Diabetes and Pregnancy Study Group (IADPSG) launched the new diagnostic criteria for gestational diabetes mellitus. In 2010, the International Association of Diabetes and Pregnancy Study Group (IADPSG) introduced new diagnostic criteria for gestational diabetes, which became a milestone in this field of research and received attention from scholars worldwide. Diagnostic criteria for gestational diabetes mellitus (GDM) The incidence of obesity and diabetes mellitus in the population is increasing, and with the increased attention paid to gestational diabetes mellitus by medical professionals, the incidence of the disease is increasing year by year, but it is not possible to compare the incidence of GDM across regions due to inconsistent diagnostic criteria used in different regions. In order to solve the long-standing controversy of GDM diagnostic criteria, a new GDM diagnostic criterion, namely 75g oral glucose tolerance test (OGTT), with diagnostic cut-off values of 5.1, 10.0 and 8.5 mmol/L for fasting, 1 hour and 2 hours after glucose administration, respectively, was developed after a multicenter, large sample study and many discussions among global experts. GDM can be diagnosed when any of the three criteria are met or exceeded. Management of gestational diabetes during pregnancy and delivery All pregnant women should have their blood glucose checked during the first antenatal checkup to exclude pre-pregnancy diabetes. If the diagnosis of GDM is made, the pregnancy will be managed as a high-risk pregnancy. The goal of blood glucose control in GDM is not to exceed 5.3, 7.8 and 6.7 mmol/L for fasting, 1 hour after meal and 2 hours after meal respectively. it is recommended to monitor micro glucose at each delivery, the more frequent the monitoring, the less maternal and fetal complications. If blood glucose control is not satisfactory, insulin therapy is recommended. The timing of delivery for pregnant women with GDM is divided into the following cases to choose different timing: 1, good glycemic control, no maternal-fetal complications, no insulin therapy, hospital admission after 39 weeks of pregnancy, termination of pregnancy before the expected date of delivery, if there is no cephalopelvic disproportion can be based on If there is no cephalopelvic disproportion, the pregnancy can be terminated according to the condition of the pregnant woman’s cervix and delivered naturally after the use of intravenous contractions or cervical maturation drugs. 2. For those who use insulin, if the blood sugar is well controlled, the pregnancy will be terminated after admission at 37-38 weeks of pregnancy. 3.For those who have a history of stillbirth or stillbirth, or complicated by preeclampsia, amniotic fluid, or placental insufficiency, terminate the pregnancy after determining fetal lung maturity or promoting fetal lung maturity. 4. In cases of diabetes mellitus with vascular lesions, the pregnancy should be terminated after 36 weeks of gestation and fetal lung maturation. Vaginal delivery should be avoided, and the blood glucose level should be controlled at 4-8 mmol/L during delivery, and caesarean section should be chosen for those with vascular lesions, severe pre-eclampsia, fetal growth restriction and fetal distress. Postpartum management of women with gestational diabetes mellitus According to the literature, about 10% of women with GDM have undiagnosed diabetes mellitus before pregnancy, and the risk of developing type II diabetes mellitus in women with GDM is 7 times higher than that of ordinary women, so the management of these women needs to be strengthened. Fasting glucose test or OGTT and glycated hemoglobin test are recommended 6 weeks after delivery. If fasting blood glucose is ≥7.0mmol/L or OGTT 2 hours blood glucose is ≥11.1mmol/L, diabetes is diagnosed and medication is required. If fasting blood glucose >6.1mmol/L and OGTT 2 hours blood glucose 7.8-11.0mmol/L, the diagnosis of impaired glucose tolerance, through diet control and exercise and other lifestyle changes to reduce the risk of chronic disease and the risk of GDM in another pregnancy.