Painless repeated vaginal bleeding during late pregnancy or at labor

The main symptom of placenta previa is the occurrence of painless repeated vaginal bleeding without inducement during the third trimester or at the time of labor. The normal placenta attaches to the posterior, anterior, or lateral walls of the uterine body. If the placenta is attached to the lower part of the uterus, or even the lower edge of the placenta reaches or covers the cervix, the position is lower than the exposed part of the fetus. Placenta previa is one of the main causes of bleeding in late pregnancy. It is a serious complication of pregnancy. Improper management can endanger the life of mothers and children. The incidence rate is 0.24% to 1.57% reported in China and 1.0% reported abroad. 85% to 90% of patients with placenta previa are menopausal, especially those with multiple births, and the incidence can be as high as 5%.