The vaginal bleeding of pregnant women at 40 weeks of pregnancy is already at full term, at this time, it may be the precursor of labor, and in a few cases, it may be bleeding due to placental reasons, it is recommended to seek medical attention in time to avoid delaying the condition. 1, the precursor of labor: 40 weeks of pregnancy is already at full term, at this time, the vaginal bleeding of pregnant women, if the bleeding is relatively small, generally do not need special treatment, can be appropriate activities to promote the uterus to start contraction, generally will In 24-48 hours there will be regular contractions, and then enter into labor; 2, placenta bleeding: 40 weeks of pregnancy vaginal bleeding, if the amount of bleeding is very large, even more than the amount of menstruation, even if there is no abdominal pain and other manifestations, you should seek medical attention in a timely manner, it may be placental abruption or placenta praevia bleeding situation. Therefore, if a pregnant woman at 40 weeks of pregnancy has vaginal bleeding, she should seek medical attention in time. The doctor will analyze the situation through ultrasound examination, fetal heart monitoring, combined with the symptoms of the pregnant woman, to determine whether she is about to give birth or other abnormal conditions.