If the pelvis is too narrow for the fetal head to pass through, it is usually not possible to have a normal delivery. Usually the obstetrician will do pelvic measurement before the delivery to assess the size of the fetus, so as to determine whether the delivery can be delivered. In addition, whether the delivery can be normal or not is also related to the size of the fetus, usually about six pounds of fetus has a higher chance of normal delivery. If it is more than eight pounds, it is called a huge baby, and the chance of a normal delivery will be significantly reduced. If the condition of the cervix is not mature, this may also lead to failure of the normal delivery, whether the normal delivery can be judged according to comprehensive factors.