Cephalo-hip diameter is the distance between the top of the head and the buttocks of the fetus. Cephalo-hip diameter can be used to estimate the week of pregnancy and determine the development of the fetus. Pregnant women can check the cephalic and breech diameters of their fetus at 7-12 weeks of pregnancy. Ultrasound can measure the distance from the top of the baby’s head to the baby’s buttocks. Generally, women who have irregular menstruation can use the fetal head-buttock diameter to estimate the pregnancy cycle and to assess whether the baby is developing normally or not. It is recommended that pregnant women should have an ultrasound at 7 weeks of pregnancy to observe the size of the cephalic to breech diameter, if the distance between the cephalic and breech diameters is too long or too short, it is necessary to consult a doctor in a timely manner. Cephalo-gluteal diameter is an important indicator to assess the development of the fetus, it is recommended that pregnant women should consult the doctor in time for cephalo-gluteal diameter examination during pregnancy, as well as other obstetrical examination programs.