The biparietal diameter of a 37-week-old fetus is 92mm, or 9.2cm, suggesting that the head of the fetus is normal. Generally in 9.00 ± 0.63cm are within the normal range, the measurement of the biparietal diameter value of 92mm in the normal range, can not indicate that the fetal head development is large, pregnant women as long as the timely participation in obstetrics, continue to pay attention to the fetal development can be. Biparietal diameter refers to the length of the widest part of the fetal head from left to right, which can be used to observe the development of the fetus and determine whether there are abnormalities such as cephalopelvic disproportion, so as to ensure that the pregnant woman can have a smooth delivery. Therefore, the observation of changes in fetal biparietal diameter during pregnancy is helpful in guiding the choice of delivery method. If large biparietal diameter occurs in late pregnancy, in addition to fetal growth factors, it is also necessary to consider whether there is the possibility of hydrocephalus, and the pregnant woman should take measures under the guidance of the doctor according to the results of the examination. Therefore, pregnant women should pay attention to reasonable dietary control in late pregnancy to avoid excessive growth of the fetus, which is not conducive to normal delivery. In addition, pregnant women should pay attention to self-counting of fetal movement, and should have regular prenatal checkups and fetal heartbeat monitoring tests to monitor the health of the fetus and the pregnant woman.