Before labor, pregnant women often experience true contractions, usually with back pain and abdominal pain, but they are different from the abdominal pain caused by general illness. The pain in the stomach before labor is paroxysmal and regular, and the pain in the stomach is accompanied by tightness and hardness of the stomach. At the beginning of the pain, the duration is relatively short and the interval is relatively long, about once every 30 minutes, and each pain lasts for about 10 seconds. As labor progresses, the pain interval gradually shortens and the pain level gradually increases, with intervals of 3-5 minutes and lasting about 30 seconds, but the exact pain sensation varies from person to person. If there are regular pains with shorter and shorter intervals and longer and longer durations, that is the beginning of real contractions. It takes about 10-13 hours from the time of regular contractions to the time of full opening of the uterus. Some pregnant women experience pseudo contractions before labor, which are usually irregular, with pain levels that are sometimes strong or weak, and usually resolve on their own, and need to be distinguished from true contractions.