Placenta previa

Placenta previa refers to the placenta attaching to the lower uterine segment or covering the internal cervical os (blocking the normal exit for fetal delivery) after 28 weeks of gestation, with its position lower than the presenting part of the fetus. Its danger lies not only in obstructing normal fetal delivery but also in being one of the main causes of late pregnancy bleeding. It is a severe complication of pregnancy, characterized by sudden onset and rapid progression, and improper management can endanger the lives of both mother and fetus. The main symptom is recurrent, painless vaginal bleeding without an apparent cause.