Bleeding in pregnancy coitus may be a priori miscarriage, cervicitis, ectopic pregnancy, preterm labor and so on. 1. Pre-eclampsia: violent stimulation during sex in early pregnancy, causing pre-eclampsia, there will be vaginal bleeding, timely bed rest, try to avoid the stimulation of sex again, if necessary, go to the hospital medication to protect the fetus treatment. 2. Cervicitis: Sex during pregnancy may cause cervical inflammation infection, suffering from cervical inflammation, sexual intercourse caused by contact bleeding, bleeding is small, mostly fresh blood. 3. Ectopic pregnancy: Bleeding during coitus in early pregnancy, but also consider bleeding caused by ectopic pregnancy. 4. Preterm labor: If you are in the late stages of pregnancy, you should consider the possibility of preterm labor after intercourse, mostly accompanied by abdominal pain and other symptoms. If you are pregnant and have bleeding after intercourse, pay attention to lie down and rest, and go to the hospital in time for treatment to preserve the fetus.