Glucose tolerance generally refers to the glucose tolerance test, which is a test that can be done at 25 weeks of pregnancy. Glucose tolerance test is generally recommended to be done between the 24th and 28th week of pregnancy. You can eat normally for three days before the test, and fast for 8-10 hours after 12:00 p.m. the night before the test. On the day of the test, you need to draw your first blood in a fasting state, and then drink 250-300ml of sugar water containing 75g of glucose within 5 minutes, starting from the first sip of the sugar water, and generally you need to test the blood glucose 1 hour and 2 hours after drinking the sugar water. Gestational diabetes has a greater impact on both the mother and the fetus during pregnancy due to the special characteristics of its constitution. It is recommended that a glucose tolerance test be done to make a clear diagnosis so as not to delay the condition.