Seven years between the first and second births does not necessarily mean that labor will progress faster. The factors of the progress of labor are not determined by the length of the interval between the first and second births, but mainly with the birth canal, the force of delivery, the size of the fetus and other factors. 1. Birth canal: It is the channel through which the fetus is delivered. If the first child is delivered smoothly, then it means that there is generally no abnormality in the birth canal of the mother and she can deliver the baby vaginally. 2. Labor force: after the contractions start, if the contractions gradually increase, the interval is gradually shortened, and the duration of pain is relatively longer, it means that the labor force is normal, and if the mouth of the uterus continues to open, most of the mothers can be delivered in 6~8 hours. 3. Fetal size: If the prenatal examination evaluates that the head of the fetus is too big, etc., the chances of vaginal delivery may be reduced, and there is even a risk of caesarean section.