Brown discharge from the vagina at 39 weeks of pregnancy may be related to preterm labor, placenta praevia, placental abruption, and so on. 1. Pre-eclampsia: Because the fetal membranes near the endocervical os and the uterine wall at that place are peeled off, there is a small amount of bleeding from the capillary rupture and mixed with the mucus plug in the cervical canal, which is discharged through the vagina, there may be a situation of brown secretion. This is generally a normal phenomenon and does not require special treatment. 2. Placenta praevia: the lower part of the uterus gradually extends in late pregnancy, pulling the cervical os, and the placenta praevia attached to the uterus or cervical os is unable to extend, which may easily cause blood vessel rupture and bleeding. Usually in late pregnancy or near labor, painless vaginal bleeding occurs, and brown vaginal discharge may appear. 3. Placental abruption: It may be due to hypertensive disorders of pregnancy, chronic kidney disease, abdominal impact and other reasons, causing the placenta to appear 1 degree of premature abruption, the vagina may appear brown discharge of the situation. If you have brown vaginal discharge at 39 weeks of pregnancy, it is recommended that you consult a doctor, follow the doctor’s instructions to choose the appropriate examination method, clarify the cause with the help of the doctor, and carry out targeted treatment or therapy.