13 weeks pregnant suddenly bleeding bright red check are normal to find out the cause, if the cervical polyps need to be removed if necessary, if the placenta hypoplasia caused by the need for bed rest and medication to protect the fetus. 1. cervical polyps: 13 weeks pregnant can be appropriate coitus, at this time may cause sudden vaginal bleeding, not accompanied by abdominal pain, to go to the hospital in a timely manner, vaginal speculum examination can assist in the diagnosis, and to give pressure to stop bleeding. However, when bleeding is repeated, polyp removal is needed, and the removed tissue should be sent for pathological examination. 2. Placenta hypoplasia: it can also cause sudden vaginal bleeding, not accompanied by abdominal pain, there can be ultrasonography suggesting that the lower edge of the placenta reaches or covers the cervical opening, absolute bed rest, prohibit coitus, and follow the doctor’s instructions to give progesterone, dydrogesterone and other medications to protect the fetus, and follow the doctor’s instructions to give penicillin and other antibiotic prophylaxis for infection treatment. Clinical when 13 weeks pregnant suddenly bleeding bright red check are normal need to go to the hospital in time to find out the cause, and actively symptomatic treatment.