In the early stages of pregnancy, the gestational sac will grow and develop in the uterine cavity, although it is not strong. However, constipation and prolonged defecation may cause contraction of the uterus due to increased abdominal pressure, accompanied by lower abdominal pain, small amount of vaginal bleeding and other cases of preterm abortion, but usually the sac will not be expelled. Unless the gestational sac itself is present with preterm or inevitable miscarriage, in the case of constipation, the uterus undergoes strong contractions due to prolonged use of abdominal pressure, which can cause the gestational sac to fall out, which is less likely. Although this chance is small, women with constipation after pregnancy should pay attention to eating more fresh vegetables and fruits as well as coarse fiber food to keep the stool as smooth as possible to prevent the occurrence of preterm miscarriage.