Brown discharge in more than six months may be caused by preeclampsia, low placenta and other reasons, which need to be analyzed specifically. 1. Pre-eclampsia: When the embryo is underdeveloped or subjected to external stimuli, the patient may have a small amount of brown vaginal discharge, accompanied by slight pain in the abdomen, after rest, the symptoms can be relieved, if not, it may develop into an inevitable miscarriage. 2. Low placenta: If the placenta is in a low position, and the lower part of the uterus elongates with the increase of pregnancy weeks, there may be painless recurrent vaginal brown discharge without obvious causes. More than six months pregnant with brown discharge may also be due to other reasons, if the patient has the above symptoms, it is recommended to consult a doctor in a timely manner, under the guidance of the doctor, improve the relevant examination, clarify the cause of the disease, symptomatic treatment.