Brown discharge at 12 weeks of pregnancy is abnormal and can be caused by pathologies such as pre-miscarriage, cervical polyps, and low lying state of the placenta. At 12 weeks of pregnancy, the placenta has formed and also has a secretory function, and the development of the fetus is relatively stable at this time. It is not normal to have brown vaginal discharge, which may be due to pathological reasons such as pre-miscarriage, cervical polyps and low lying placenta, etc. It is necessary to go to the hospital in time for ultrasonography and gynecological examination to assist in the diagnosis. In addition, after the 12th week of pregnancy, we should pay attention to appropriate rest, and should not carry out heavy physical labor. As the early pregnancy reaction has basically disappeared at this time, you can appropriately increase the dietary nutrition, such as eating more food containing protein, calcium, iron and vitamins and other nutrients, in order to meet the needs of the fast-growing fetal development. Clinically, when there is a vaginal flow of brown discharge need to identify the cause under the guidance of the doctor, and actively deal with.