Bleeding from the placenta in the sixth month of pregnancy may refer to the presence of blood in the vagina, the causes of which include pre-miscarriage, cervical insufficiency, placental abruption, cervical pathology, and placenta hypoplasia. 1. Pre-eclampsia: Bleeding can be a sign of pre-eclampsia for pregnant women in their sixth month of pregnancy. The first symptom is often vaginal bleeding, which is usually small, often dark red, and lasts up to 4-5 days to more than a week. Secondly, pregnant women may sometimes experience bouts of abdominal pain. This situation should be treated under doctor’s guidance for birth control. 2. Cervical Insufficiency: Pregnant women with cervical insufficiency may experience dilatation of the uterine opening at around six months of age as the fetus grows larger, which may cause vaginal bleeding, as well as a sensation of lower abdominal cramping. When this happens, ultrasonography can be used to make a clear diagnosis and treatment can be carried out under the guidance of the doctor to preserve the fetus. 3. Placental abruption: After the sixth month of pregnancy, there is a risk of placental abruption, which mostly manifests as persistent abdominal pain with bleeding, which is mostly bright red and can be the same as the amount of menstruation, and pregnant women with water breakage can manifest bloody amniotic fluid and poor uterine relaxation. Placental abruption is an emergency situation, there is always the risk of acute fetal distress, fetal death in the uterus, the need for immediate medical attention. 4. Cervical lesions: pregnant women suffering from cervical polyps, cervicitis and other diseases may have a small amount of vaginal bleeding around the sixth month of pregnancy, gynecological examination and routine examination of the leukorrhea can be carried out to make a clear diagnosis and then treat the symptoms. 5. Placenta hypoplasia: the placenta is in a low position, reaching or close to the endocervical os, sometimes with the enlargement of the uterus, vaginal bleeding may also occur.