After the middle of pregnancy, the uterus will gradually become sensitive, such as external stimuli will lead to uterine contractions, which are painless and will be relieved by contractions in about 10 seconds, which indicates that the uterus is relatively sensitive and will not have any effect on the fetus. However, frequent contractions can cause intrauterine oxygen deprivation in the fetus. Therefore, once frequent contractions occur, it is necessary to go to the hospital for examination. If the contractions are more serious, you need to have a tranquilizing treatment. For example, some smooth muscle relaxation drugs are used to ease the frequent contractions of the uterus, to tranquilize the fetus, and at the same time, oxygen is given to ensure the safety of the fetus in the uterus.