Cesarean section of one child and placenta praevia with single umbilical artery of the second child, whether the delivery can be normal or not needs to be assessed in the context of the specific situation of the pregnant woman, if the pregnant woman has pelvic stenosis, fetal malposition, aggressive placenta praevia, placenta praevia covering the cervical os, and a huge fetus, etc., it is usually not recommended to have a normal delivery. A pregnant woman who has had a cesarean section with her first child may have reasons why she cannot have a normal delivery, such as pelvic stenosis and fetal malposition, and if this is still the case with her second child, she will still not be able to have a normal delivery. Pregnant women with placenta praevia cannot have a normal delivery if the placenta covers the cervical opening. Pregnant women with placenta praevia grows in the scar position, the emergence of menacing placenta praevia, pregnant women also can not go through labor. Fetal single umbilical artery part of the pregnant woman can be delivery, but pregnant women at the same time combined with a scarred uterus, placenta praevia, the risk of delivery will be greatly increased, the specific can be delivery or need to be assessed by the doctor according to the specific circumstances of the delivery of pregnant women.