The brown discharge in the fourth month of pregnancy can be considered as a pre-eclampsia, low placenta, gynecological diseases, etc., respectively, you need to protect the fetus, pay attention to life care, for disease treatment and other measures. 1. aura miscarriage: four months pregnant with brown discharge may be aura miscarriage, pregnant women will also be accompanied by abdominal pain, abdominal distension and other symptoms, you can bed rest, timely use of progesterone and other drugs to protect the fetus. 2. low placenta: more than four months pregnant with brown discharge may be low placenta, it is recommended that pregnant women more bed rest, prohibit coitus, avoid strenuous exercise, regular observation. 3. Gynecological diseases: pregnancy four months more brown discharge may cervical inflammation, vaginal inflammation, cervical polyps and other gynecological diseases, need to be targeted treatment, such as pregnant women cervical inflammation can be used locally nitrofurantoin mycobacteria vaginal suppositories and other medications, pay attention to the vulva hygiene and so on. Pregnant more than four months with brown discharge, should go to the regular hospital in a timely manner, by the doctor to guide the use of medication.