| One cause of vaginal bleeding is placenta previa. In placenta previa, the placenta is attached in a position that is low in the uterus, near the cervical os. There are varying degrees of placenta previa. With low implantation, the placenta is implanted in the lower uterus but does not infringe on the cervical os until dilation occurs. Partial placenta previa refers to partial coverage of the os by the placenta, and the complete placenta previa refers to the placenta completely covering the os. Risk factors are multiparity, increased maternal age, a previous pregnancy with placenta previa, prior caesarean section, uterine fibroids, a history of smoking, and multiple gestations. Painless vaginal bleeding is the hallmark of placenta previa. If a patient has placenta previa, manual and speculum vaginal examinations are contraindicated, to prevent inducing a large hemorrhage. | | | | |