The OGTT is a mandatory test, so pregnant women must have it because gestational diabetes is a relatively common complication of pregnancy, and it has adverse effects on both mother and child, so it should be checked regularly. The test is usually performed between 24 and 28 weeks of pregnancy, with fasting blood and blood glucose one hour and two hours after taking 75g of sugar, respectively. If all three criteria are below 5.1mmol/L, 10.0mmol/L and 8.5mmol/L, it is normal. If one of these criteria is higher than the above, the diagnosis of gestational diabetes is straightforward. Patients with gestational diabetes should promptly contact their endocrinologist and obstetrician mutual help, which can be helped by diet regulation exercise and, if necessary, medication.