Redness is defined as a small amount of bloody vaginal discharge. It is not normal to have bloody discharge in early pregnancy. Generally speaking, the causes of bloody discharge in early pregnancy can be divided into the following categories: a. Premature miscarriage In early pregnancy, if the embryo is unstable in bed or if the embryo itself is developing abnormally, spontaneous early pregnancy miscarriage can occur. Before miscarriage, pregnant women will have vaginal blood discharge, so redness is a sign of miscarriage. Second, cervical polyps Cervical polyps can occur during pregnancy with a small amount of bleeding. A small amount of blood combined with vaginal discharge can form a bloody discharge. When this happens, the patient needs to seek medical attention and, if necessary, a cervical polyp removal. Third, low progesterone Insufficient development of the ovarian corpus luteum in early pregnancy can trigger the situation of insufficient progesterone secretion in the body. When the progesterone secretion is insufficient to support the continuation of pregnancy, vaginal redness may occur. In this case, progesterone supplements should be given and the amount of vaginal bleeding should be monitored and, if necessary, hospitalized for fetal preservation. In conclusion, redness in the third trimester can be caused by preterm abortion, low progesterone and cervical polyps.