The average weight gain in late pregnancy is 350g per week until full term, when the average weight gain is about 12.5kg. There is no obvious change in the weight of pregnant women in the early stage of pregnancy, and the weight gradually increases with the increase of gestational weeks in the middle and late stages of pregnancy. Along with the increase of gestational weeks, pregnant women may appear uterus enlargement, feel fetal movement, hear fetal heart sound and other manifestations. When pregnant women gain weight too quickly, it will increase the risk of diabetes and hypertension; if pregnant women gain weight too slowly, it will lead to malnutrition and the possibility of fetal growth and development restriction. When a pregnant woman gains weight too quickly or too slowly, she should be vigilant, adjust her diet, exercise appropriately, go to the hospital if necessary, and follow the doctor’s instructions for treatment to minimize the impact on the mother and child.