Biparietal diameter is large, if it is caused by genetic factors, can not be controlled, if it is caused by dietary factors, can be controlled. 1. Genetic factors: through the examination of fetal weight in the normal range, just biparietal diameter is large, if it is caused by genetic factors, through dietary methods can not be changed, but because of the phenomenon caused by genetic factors, do not need to take special measures. 2. Dietary factors: If it is due to excessive consumption of nutritious food during pregnancy, the exercise is relatively small, resulting in a large biparietal diameter. You need to pay attention to a reasonable diet and moderate exercise, which can effectively control the weight of the fetus and the weight of the pregnant woman, and can improve the situation of large biparietal diameter. During pregnancy, you need to pay attention to rest, but not sedentary, you can take some moderate exercise methods, according to the doctor’s instructions to do the relevant examinations during pregnancy.