Vomiting blood during pregnancy is usually abnormal and may be due to more severe pregnancy reactions, gastrointestinal bleeding, other systemic diseases and other reasons. 1. Severe pregnancy reaction: If a pregnant woman suffers from more severe pregnancy reaction during pregnancy, such as nausea, vomiting, etc., these pregnancy reactions will cause mucous membrane bleeding, which will lead to the symptom of vomiting blood. 2. Gastrointestinal bleeding: if the pregnant woman herself suffers from gastric ulcer, gastritis, enteritis and other diseases, and does not pay attention to personal eating habits, after eating spicy and stimulating food, the symptoms of vomiting blood during pregnancy may occur. 3. Other systemic diseases: If the pregnant woman has abnormal liver and kidney function or stomach cancer or intestinal cancer, it may cause vomiting blood during pregnancy. In conclusion, if a pregnant woman has symptoms of vomiting blood, she should consult a doctor in time. Under the doctor’s guidance, she should complete the relevant examinations, identify the cause of the disease and treat it accordingly.