The folk saying of opening the bone suture is actually the dilatation of the cervical opening. The opening of 10 bone sutures means that the cervical opening will be 10cm, or the full opening of the cervix. Pregnant women approaching labor, with regular contractions, will push the head of the fetus down, the head of the fetus down compression of the cervical opening, prompting the disappearance of the cervix, cervical dilatation. In other words, there is no sensation of opening the gap between the bones, and what you feel is the pain of contractions. After the opening of the uterus, the head of the fetus gradually descends, at this time, you can let the mother hold her breath to push the head of the fetus to continue to descend, until the fetus is delivered.