Brown discharge at 34 weeks of pregnancy, usually a small amount of vaginal bleeding, may be associated with preterm labor, placental abruption, placenta praevia and other causes. 1. Preterm labor: refers to the pregnancy reaches 28 weeks but less than 37 weeks of delivery, its main clinical manifestations for irregular contractions, there may be a small amount of vaginal bleeding or bloody secretion, when the secretion in the vagina after the accumulation of brown. 2. Placenta previa: the placenta in normal position can be partially detached from the uterine wall before the delivery of the fetus, which can be considered to be related to vascular lesions such as hypertensive disorders of pregnancy, blunt trauma to the abdomen, and advanced age of multiparous pregnant women, etc. There may be a small amount of bleeding, which will stay inside the vagina and become brown secretion to be discharged out of the body. 3. Placenta praevia: the most common cause of vaginal bleeding in late pregnancy, after 28 weeks of gestation, the placenta position is lower than the fetal preluteal part, its attachment to the lower uterine segment, the lower edge can reach or cover the cervical opening, in the cervical dilatation, the placenta can be part of the anterior portion of the separation of the attachment, the rupture of blood sinus bleeding, the general amount of first-time bleeding is less, the blood oxidizes to form a brown secretion in the vagina. 34 weeks pregnant women found brown or bloody discharge, it is recommended to promptly go to the hospital specialist consultation, follow the doctor’s instructions for treatment.