24 weeks to do glucose tolerance will not be early, belongs to the normal examination time, this test can determine whether the pregnant woman suffers from gestational diabetes. Glucose tolerance is generally referred to as oral glucose tolerance test, which refers to the measurement of plasma glucose concentration within 2h after oral glucose dosing, so as to understand the function of pancreatic β-cells and the body’s ability to regulate blood glucose, and is mainly used for the diagnosis of diabetes mellitus. Pregnant women are required to undergo oral glucose tolerance test at 24~28 weeks of pregnancy, and it is not premature if pregnant women undergo it at 24 weeks. Generally speaking, the normal fasting blood glucose value is 3.9~6.1mmol/L, 0.5~1h after oral glucose, blood glucose reaches the peak value needs to be <11.lmmol/L, 2 hours of blood glucose needs to be <7.8mmol/L, 3 hours of blood glucose can be restored to the normal fasting level. If one of the above test results is out of the normal range, it can be judged as gestational diabetes mellitus, the specific need to follow the doctor's advice. Once a pregnant woman is diagnosed with gestational diabetes mellitus, she should actively cooperate with her doctor to take relevant treatment measures.