The bleeding at 31 weeks of pregnancy is considered to be cervical erosion, placenta praevia, heavy placenta abruptio or preterm delivery, which should be promptly examined by a doctor and treated differently according to individual conditions. 1. cervical erosion: cervical erosion, also known as cervical columnar epithelial ectopic, has mild symptoms and common vaginal discharge with blood. If there is no other symptom, there is no need to be overly nervous, usually pay attention to hygiene, can be regularly reviewed to avoid cervicitis and other diseases; 2, placenta praevia: 31 weeks of pregnancy, no cause, painless, recurrent vaginal bleeding, first of all, consider placenta praevia, at this time should promptly seek medical attention, suppress contractions, correct anemia, etc., while paying attention to a reasonable diet, more rest; 3, heavy placenta Premature abruptio: heavy placenta abruptio is internal bleeding, so it shows no vaginal bleeding, or a small amount of bleeding, accompanied by sudden and continuous abdominal pain or lumbar pain, at this time, you should seek medical attention, if necessary, give oxygen, blood transfusion, etc.; 4, preterm labor: pregnant women in preterm labor will have a small amount of vaginal bleeding or symptoms of bloody discharge, accompanied by irregular contractions, and then develop into regular contractions, at this time, you should seek medical attention as soon as possible, try to If you can’t avoid preterm delivery, you should seek medical attention as soon as possible and try to preserve the fetus. In conclusion, if there is no other symptom when there is a small amount of bleeding at 31 weeks, there is no need to be nervous, so you can seek medical attention and make good health care. If it is accompanied by other symptoms such as abdominal pain and contractions, you should seek medical attention as soon as possible to avoid the situation becoming more serious and pay attention to rest at the same time.