It is necessary to do a glucose tolerance test during pregnancy maternity checkup, and it is not recommended not to do it. Because during pregnancy, the placenta secretes substances that resist the function of insulin and interfere with the pregnant woman’s glucose metabolism, which can easily lead to gestational diabetes and have a greater impact on the near and long-term complications of the mother and child, it is recommended that pregnant women who are able to do a glucose tolerance test within 24-28 weeks of pregnancy to clarify the diagnosis, and it is easy to miss the diagnosis by only checking fasting blood sugar. There are many adverse effects of gestational diabetes on pregnant women and fetuses. When gestational diabetes occurs, the mother is prone to infections and the possibility of combined gestational hypertension increases; in severe cases, pregnant women may also develop ketoacidosis, and it may easily lead to fetal malformations, such as giant babies or fetal birth injuries, neonatal hyperbilirubinemia, etc.; maternal hyperglycemia may also lead to abnormal embryonic development or even death. Therefore, pregnant women need to take a glucose tolerance test to clarify the presence of gestational diabetes as early as possible, and to control blood sugar reasonably to avoid adverse pregnancy outcomes. The glucose tolerance test requires the drawing of venous blood for examination, so it is necessary to keep fasting, i.e. after dinner the previous day, fasting for at least 8 hours until the next morning, and oral anhydrous glucose can be taken after the blood is drawn, and the patient’s fasting blood sugar, blood sugar after 1 hour, and blood sugar after 2 hours will be judged by monitoring. In addition, pregnant women need to pay attention to avoid smoking, drinking alcohol, coffee and strong tea 3 days before the examination, and adjust their work and rest time to avoid exertion and staying up late.