In general, twin pregnancies weigh 1500-2000g at 36 weeks, but there are specific individual differences. The fetal development in the mother is clinically found to have a certain regularity. In case of singleton pregnancy, the fetal biparietal diameter at 36 weeks of pregnancy is 8.8-8.9 cm, the femur length is 6.7 cm, and the fetal weight is about 2500g, when more fat already exists under the skin. In the case of twin pregnancies, the fetus absorbs relatively less nutrients from the mother than in a singleton pregnancy, which generally results in a lower fetal weight than in a singleton pregnancy, which may be 1500-2000g at the end of 36 weeks, but there are individual differences in the specific fetal weight due to the specific nutrients absorbed by the mother. In addition, 36 weeks has entered the late stage of pregnancy and special attention should be paid to the number of fetal movements so as not to miss the best time for treatment if abnormalities of the fetus in the uterine cavity are not detected. At the same time, women should pay attention to a balanced diet and comprehensive nutrition during pregnancy to ensure the needs of fetal growth and development.