Blood discharge in mid-pregnancy may be caused by pre-eclampsia, cervical polyps and so on. 1. Pre-eclampsia: can be manifested as a small amount of vaginal bleeding, can also be accompanied by paroxysmal pain in the lower abdomen, ultrasound suggests that the fetal development is normal, the placenta is in a normal position, combined with the clinical manifestations can assist in the diagnosis, you need to pay attention to the appropriate activities, prohibit coitus, and give medication to protect the fetus treatment. 2. Cervical polyps: can also cause a small amount of vaginal bleeding, can be manifested as the flow of discharge with blood, not accompanied by abdominal pain, ultrasound, gynecological examination to assist in the diagnosis of the symptoms are not obvious may not need special treatment, but when repeated bleeding needs to be carried out in the cervical polyp removal surgery, the removal of tissue sent to the pathology, and local compression to stop bleeding. When there is blood discharge in mid-pregnancy, you need to go to the hospital in time to find out the cause and actively treat it.