Brown vaginal discharge in early pregnancy may be caused by bleeding on implantation, preeclampsia, miscarriage, ectopic pregnancy, scarred pregnancy, cervical polyps and other diseases. 1. Bleeding on implantation: When the embryo is implanted, it can break through the uterine lining, resulting in a small amount of vaginal bleeding, which usually requires no treatment. 2. Aura of miscarriage, abortion: when abdominal pain and vaginal bleeding occur before 28 weeks of pregnancy, it should be recommended to improve ultrasound, human chorionic gonadotropin, progesterone and other tests to understand the development of the embryo, and whether there is aura of miscarriage, abortion. 3. Ectopic pregnancy, scarred pregnancy:Ectopic pregnancy and scarred pregnancy may also present with small amount of vaginal bleeding, and vaginal ultrasound can be perfected to exclude abnormal pregnancy position. 4. Cervical polyps: For repeated fertility preservation treatment is ineffective, still have vaginal bleeding, should check whether there are cervical polyps and other diseases. If you have brown vaginal discharge in early pregnancy, it is recommended to consult a hospital as soon as possible to clarify the cause of the disease and treat the symptoms.