The reason for hemorrhage may occur in all stages of pregnancy, but it varies. There are more reasons for hemorrhage in early pregnancy, mostly related to the pregnant woman’s own diseases and physical abnormalities. 1, miscarriage: miscarriage in early pregnancy will be accompanied by uterine contractions, uterine contractions can compress blood vessels and play a hemostatic role, and hemorrhage is likely to occur when uterine contractions are weak. 2, abnormal coagulation function: consider that the patient may have abnormal coagulation function or other medical diseases, resulting in abnormal coagulation factors, causing hemorrhage The patient should check the blood routine, combine with other clinical symptoms, signs and examination to determine the cause, and if necessary, blood transfusion is needed; 3, vaginal and cervical diseases: hemorrhage may be caused by vaginal or cervical lesions, for example, the patient has vaginal polyps or ruptured cervical polyps, cervical neoplastic lesions, etc. If these lesions have mass rupture, hemorrhage can also occur; 4, placenta praevia: the placenta covers the The placenta is one of the main causes of late pregnancy bleeding; 5, placenta abruptio: after 20 weeks of pregnancy or during delivery, the placenta in normal position is partially or completely detached from the uterine wall before the delivery of the fetus, which often causes sudden and persistent abdominal pain, back pain, lumbago and other symptoms in pregnant women, and the degree of pain is related to the amount of blood accumulated in the uterus after placenta abruptio. The degree of pain is related to the amount of accumulated blood in the uterus after placental abruption. During pregnancy, care should be taken to keep the surrounding environment safe and avoid mechanical abdominal injuries that may cause miscarriage or premature delivery. In addition, pregnant women should try to avoid sexual intercourse, maintain a regular lifestyle and a healthy diet, and keep a positive and optimistic attitude. In case of hemorrhage during pregnancy, she should seek medical attention at the first opportunity and call the emergency number if necessary.