What is the most likely cause of postpartum hemorrhage in a woman with a history of cesarean delivery?

The most likely cause of postpartum hemorrhage in a woman with a history of cesarean delivery is placenta accreta. This condition occurs when the placenta implants too deeply into the uterine wall, often invading surrounding tissues. The risk of placenta accreta increases in women who have had previous cesarean deliveries due to potential scarring of the uterine lining, which can disrupt normal placental implantation.

In cases of placenta accreta, during delivery or postpartum, the placenta may not detach properly from the uterine wall, leading to significant blood loss. The presence of scar tissue from a cesarean section may create a pathological environment for the placenta, making it more likely to adhere abnormally. Consequently, this can result in retained placental tissue and considerable bleeding after birth, which characterizes postpartum hemorrhage.

Other conditions listed, such as abruptio placentae and ectopic pregnancy, are less relevant to the scenario of postpartum hemorrhage following cesarean delivery. Abruptio placentae typically occurs antepartum and is related to placental separation prior to delivery. Ectopic pregnancies occur when the embryo implants outside the uterus and would not be a direct cause of postpartum hemorrhage. Endometriosis involves endometrial tissue growing outside the uterus and