Ultrasound can roughly tell whether the fetus is in the pelvis, but it cannot specifically know whether the fetus is in the pelvis. Maternity checkups usually do not check whether the fetus is in the pelvis through ultrasound, but through a simple four-step palpation method to determine. When the biparietal diameter of the fetal head reaches the inlet plane of the mother’s pelvis and the lowest point of the fetal head’s skull is close to or reaches the level of the sciatic spine, the fetus is said to be in the pelvis. Ultrasound can show that the fetal head is leaning down significantly, due to the position of the fetal head, it can not be 100% confirmed whether the fetus is in the pelvis, after the fetal head is in the pelvis ultrasound can not clearly measure the biparietal diameter, then it is considered to be the fetus is in the pelvis. Fetal pelvic generally through the obstetrics four-step palpation method to determine, in the pubic symphysis above the fetal head, gently push the feeling of floating ball, can be pushed under the state of the fetal head is high floating did not enter the pelvic, gently push the fetal head is not obvious activities, consider the fetus into the pelvic. To determine whether the fetus is in the pelvis in late pregnancy, it is recommended to go to the hospital to find out through the vaginal examination.