Each pregnant woman’s body condition is different, so it is not possible to make an accurate judgment on how long it takes for the uterus to open. If the baby is born at full term, the uterus will slowly increase in size about 4-6 hours after the painful contractions, and the time for the uterus to open varies due to the different degrees of softness and hardness of the uterus. If the pregnant woman is giving birth for the first time, it will take about 11-12 hours after the contraction for the opening of the uterus to be fully opened so that the baby will be born. The relative opening time of the uterus is faster for menstruating women, and it will be fully opened in about 6 hours, but it depends on the situation. After the opening of the uterus, pregnant women must go to the hospital in time for a checkup and make preparations for the relevant delivery. Usually, they must pay attention to observe their body conditions, and if there are various problems such as bleeding and abdominal pain, it is recommended to go to the hospital for examination and treatment in time to avoid abnormal reactions.