There is no standardized weight for pregnant women in their 6th month of pregnancy. Because every pregnant woman’s physical condition before pregnancy is different, the body mass index before pregnancy is generally used to judge the weight gain after pregnancy, the body mass index that is, BMI = weight (kilograms)/height (meters)2. The BMI value of adults is divided into too light BMI <18.5, normal BMI=18.5-23.9, overweight BMI>24. If a pregnant woman is too light before pregnancy, it is recommended to gain 0.5kg per week from the middle to the end of pregnancy. If a pregnant woman is underweight before pregnancy, it is recommended to gain 0.5kg per week from mid-pregnancy to late pregnancy, and in the 6th month of pregnancy, the weight gain of a pregnant woman is about 5-6kg. if a pregnant woman is of normal weight before pregnancy, it is recommended to gain 0.4kg per week from mid-pregnancy to late pregnancy, and therefore in the 6th month of pregnancy, the weight gain of a pregnant woman is about 4-5kg. for pregnant women who are overweight before pregnancy, the magnitude of the weight gain should be reduced from 0.2-0.3kg per week from mid-pregnancy to late pregnancy, and it is recommended that they gain 0.2-0.3kg per week. 0.2-0.3kg per week, and the weight gain in the 6th month of pregnancy is about 3-4kg. during pregnancy, pregnant women should pay attention to monitoring their own weight, and if the weight gain is faster, they should control their diet reasonably, exercise moderately, and slow down their weight gain while ensuring the normal development of the fetus. If the weight gain is low and the fetus grows slowly, she should pay attention to increasing nutrition and eating more diets rich in high quality protein and nutrients, so as to promote the healthy growth and development of the fetus.