The brown discharge from the vagina during pregnancy is very likely to be blood, which may be due to preeclampsia, ectopic pregnancy, cervicitis and other reasons. 1. Pre-eclampsia: Pregnant women with luteal insufficiency, poor endometrial tolerance, or poor sperm and egg quality can experience pre-eclampsia, which usually results in brown discharge. 2. Ectopic pregnancy: In the case of ectopic pregnancy, the gestational sac is not active, so pregnant women are prone to miscarriage, resulting in abnormal vaginal discharge, usually accompanied by abdominal pain and other symptoms. 3. Cervicitis: pregnant women with cervicitis, the local mucous membrane is weak, this situation is often accompanied by increased vaginal discharge, local redness, swelling and discomfort, which leads to the emergence of brown discharge. During pregnancy, if there is a slight bleeding, through appropriate rest can not be relieved, showing a persistent aggravation of the trend, and accompanied by abdominal pain manifestation, should be early to consult a doctor, a clear diagnosis of the causative factors, under the guidance of the doctor for symptomatic treatment and conditioning. At the same time, you should relax and avoid tension and anxiety.