The 12 weeks of pregnancy is a sensitive time in pregnancy, the hormone level and fetal development are relatively unstable, at this time if the brown discharge does not need to worry too much, most of them are caused by unstable hormone level or gynecological inflammation, you can go to the regular hospital obstetrics and gynecology consultation, after reasonable intervention and treatment can be normal pregnancy. A few cases may be related to ectopic pregnancy, placenta position is too low, pre-eclampsia and other reasons, need to be checked to clarify the causes after intervention treatment. 1, unstable hormone levels: early pregnancy hormone levels change a lot, there may be bleeding similar to menstruation, also called pregnancy menstruation, but the amount of bleeding is very small, manifested as brown discharge, and the time duration is relatively short, usually two or three days will disappear, as long as there is no As long as there is no abdominal pain, fever and other discomfort, there is generally no need to worry; 2. Gynecological inflammation: If you suffer from gynecological inflammation such as vaginitis and cervicitis before pregnancy, or if the pathogenic microbial infection causes gynecological inflammation because of the decrease in resistance after pregnancy, there may be a small amount of vaginal bleeding, which is manifested as brown discharge and may be accompanied by slight abdominal pain, you can go to the hospital for examination and apply anti-inflammatory medication under the guidance of the doctor; 3. Ectopic pregnancy: if there is obvious abdominal pain, lumbago, weakness and other discomforts besides brown discharge, you can go to the hospital for gynecological ultrasound examination to determine whether there is ectopic pregnancy, and if it is determined to be ectopic pregnancy, the doctor should determine whether to carry out conservative treatment or surgical termination of pregnancy; 4. It usually does not cause abdominal pain, and the placenta position can be determined by applying ultrasound examination. Generally, the symptoms can be reduced by appropriate bed rest and avoiding strenuous activities, and termination of pregnancy can be considered in case of heavy bleeding; 5. If clinical symptoms worsen, ultrasound examination reveals that the embryo is poorly developed, and blood HCG continues not to rise or fall, it indicates that miscarriage is inevitable and the pregnancy should be terminated; 6. Cervical causes: diseases such as cervical polyps, cervical erosion or cervical cancer can also cause bleeding, which need to be clearly diagnosed through gynecological examination at the hospital and treated symptomatically by applying drugs or surgery under the guidance of doctors. If brown discharge appears during pregnancy can be relieved on its own after proper rest, it usually does not need to be treated. If the bleeding symptoms gradually worsen and are accompanied by other discomfort, you need to seek medical treatment in time. In the early stages of pregnancy, you should pay attention to regular maternity checkups, take folic acid supplements as prescribed by your doctor, pay attention to rest and avoid overexertion, refrain from intercourse in the first three months of pregnancy, and avoid contact with toxic and harmful physical and chemical substances as much as possible to prevent pre-miscarriage.