There is no scientific basis for whether it is better to have a posterior or anterior wall birth. The factors that determine labor and delivery are the force of delivery, the birth canal, the fetus, and psycho-psychological factors. 1. Labor force: refers to the power to expel the fetus and appendages from the uterus, which is composed of abdominal wall muscle contraction, uterine contraction, levator ani muscle contraction, diaphragm contraction, the better the labor force, the faster the progress of labor. 2. Birth canal: it refers to the channel through which the fetus is delivered from the mother, including the bone birth canal and the soft birth canal. The labor progresses smoothly if the bone birth canal is in good condition, without pelvic deformity and stenosis, and if there is no developmental abnormality in the soft birth canal. 3. Fetus: mainly refers to the size of the fetus and the position of the fetus with or without abnormalities. Usually, if the fetus is overweight and the position of the fetus is abnormal, the progress of labor will be slow and the risk of obstructed labor will be high. 4. Spiritual and psychological factors: mainly refers to the mental state of pregnant women, abnormal fear of labor, nervousness can lead to endocrine disorders, affecting the progress of labor, resulting in obstructed labor. The labor force, birth canal, fetus and mental and psychological factors affect each other during delivery. Whether or not you can have a normal delivery should be guided by a professional doctor to avoid blindly having a normal delivery, which may lead to adverse consequences.