The first stage of labor, also known as the cervical dilatation period, refers to the period from regular contractions to full opening of the uterus, divided into two stages, including the latent period and the active period. The latent period refers to the period from the beginning of regular contractions to the beginning of the active period (the opening of the uterus to 4-6 cm), and the beginning of labor is characterized by regular contractions of 5-6 minutes or 4-5 minutes of pain for 25-30 seconds or even longer, accompanied by the receding of the cervical canal and the opening of the uterus. The incubation period usually does not exceed 20 hours for primiparous women and 14 hours for menstrual women. The active period takes an average of 4-8 hours. The first stage of labor mainly depends on the contraction force to open the opening of the uterus, without maternal exertion, so it is recommended for pregnant women to bear the pain, preserve their strength and keep a good attitude.