The maximum intensity of contraction pressure is 100%, when a woman’s uterine contraction reaches its maximum intensity, the contraction is 100%. Contractions are gradually rising, no contraction contraction pressure is generally maintained at about 10%, with the beginning of contractions, contraction pressure will be rising incrementally, from the low value slowly reach 100%, 100% is already the peak, generally at 100% contraction pressure lasts for 20-30 seconds, the contraction will be significantly decreased again, spaced out for a few minutes at a time, which is very regular. Regular contractions after labor is imminent, the regular rise in contraction pressure can soften the cervix of the pregnant woman, so that the mouth of the uterus is open and the fetal head is descending. Contractions are also a very important factor in facilitating labor, during labor if the contractions are normal, most of them can be delivered normally, if the contractions are not coordinated will increase the risk of difficult labor.