A biparietal diameter of 83mm at 29 weeks of pregnancy is slightly greater than normal and is considered normal if no abnormalities such as hydrocephalus are ruled out. The normal range for biparietal diameter at 29 weeks of pregnancy is about 72mm. The size of the biparietal diameter of the fetus varies a lot in the same week of pregnancy. The height and weight of the fetus are related to genetics as well as the lifestyle and diet of the pregnant woman, and it is normal for the fetus to be larger than 10 days in 29 weeks of pregnancy. Need to pay attention to a reasonable diet, do not eat too much nutritious food, in the diet of the best meat and vegetables through, pay attention to a reasonable diet, moderate exercise, not only can improve the physical quality of pregnant women, but also appropriate control of fetal weight too fast growth. Pregnant women should regularly go to the hospital for maternity checkups, do a good job of pregnancy related checks, and find abnormalities at any time to deal with.