The reason for doing the glucose tolerance test at 24 weeks is that blood glucose is more stable at this stage, as well as the rapid growth of the fetus at this time, and screening at this time is the easiest way to detect blood glucose abnormalities. 1. Starting from early pregnancy, pregnant women’s blood glucose is in a downward trend, and reaches a stable level around six months, so it is more appropriate to do the glucose test at this stage. Because of the early sugar test, due to the early pregnancy blood sugar will appear a certain degree of decline, at this time to do glucose tolerance may cover up gestational diabetes. 2. At this time, the fetus is in the rapid growth period, and the secretion of anti-insulin hormone in the pregnant woman’s body is large, and there will be a variety of risk factors for diabetes; if the pregnant woman is observed to have glucose metabolism disorders at this time, then it can also be treated as early as possible, so that it can be avoided because of the delayed condition, which affects the health of the pregnant woman and the growth and development of the fetus.