Vaginal bleeding does not normally occur during pregnancy, so it is important for pregnant women to pay attention to it when it does occur. In general, the effect of vaginal bleeding on the fetus depends on the amount of vaginal bleeding and the duration of vaginal bleeding. If the amount of vaginal bleeding is relatively small and the duration of bleeding is short, then the effect of vaginal bleeding on the fetus is not significant. However, the cause of the vaginal bleeding needs to be identified. The patient is advised to consult the local hospital immediately and take appropriate treatment according to the cause. If the amount of vaginal bleeding is as heavy as menstrual bleeding, then there is a possibility of hemorrhagic shock in a short period of time. In this case, the fetus will experience ischemia and hypoxia in the uterus. In severe cases, intrauterine fetal death can occur. It is also necessary to clarify the effect of vaginal bleeding on the fetus depending on the etiology that caused the vaginal bleeding during pregnancy. For example, if placental abruption causes vaginal bleeding, the fetus will experience ischemia and hypoxia for a short period of time, or even die. If placenta praevia causes vaginal bleeding, then the effect on the fetus is relatively small. Therefore, the effect of bleeding in pregnancy on the fetus depends on the cause of the bleeding and the amount of bleeding.