After seeing red in the second trimester, if there are no other abnormal effects on the pregnant woman most of them go into labor within 24-48 hours, and a few within a week. Redness is one of the symptoms of labor with premonitory signs. As the fetal membranes near the opening of the cervix peel away from the uterine wall there, a small amount of bleeding occurs after the capillaries rupture, and after mixing with the mucus plug in the cervical canal, it will be discharged through the vagina. The beginning of labor is signaled when the woman experiences regular and gradually increasing contractions. There are two more stages of labor between the onset of redness and delivery. Usually, the cervix is looser and the opening of the uterus dilates more quickly, so the first stage of labor takes 6-8 hours from the beginning of labor to the opening of the uterus, and the second stage of labor takes a few minutes from the opening of the uterus to the delivery of the baby. In addition, if the amount of vaginal bleeding of pregnant women is more than the amount of daily menstruation, we should be more vigilant, and need to promptly rule out placenta previa and other factors caused by bleeding in late pregnancy.