Placenta previa in a patient with a prior uterine scar raises concern for which abnormal placentation that increases the risk of emergency cesarean hysterectomy?

Placenta previa in a patient with a prior uterine scar raises concern for which abnormal placentation that increases the risk of emergency cesarean hysterectomy?

• A. Placenta Accreta
• B. Placenta Previa
• C. Placental Abruption
• D. Uterine Rupture

Answer: (A)

When a placenta implants over a scarred uterus, abnormal placentation can occur where placental tissue invades into the myometrium. This is the placenta accreta spectrum, with placenta accreta being the classic form. The defective decidual layer in scarred uterine tissue allows the placental villi to attach directly to the myometrium, making separation after delivery very difficult and leading to heavy postpartum hemorrhage. Because this bleeding can be life-threatening, emergency cesarean hysterectomy is a common and often required management step. The combination of placenta previa (placenta over the cervix) and a prior uterine scar especially raises the risk for this invasive placentation. By contrast, placenta previa itself describes placental location without invasion; placental abruption involves premature separation of a normally implanted placenta; and uterine rupture is a full-thickness tear of the uterine wall—serious, but not an invasion of placental tissue into the myometrium.

When a placenta implants over a scarred uterus, abnormal placentation can occur where placental tissue invades into the myometrium. This is the placenta accreta spectrum, with placenta accreta being the classic form. The defective decidual layer in scarred uterine tissue allows the placental villi to attach directly to the myometrium, making separation after delivery very difficult and leading to heavy postpartum hemorrhage. Because this bleeding can be life-threatening, emergency cesarean hysterectomy is a common and often required management step. The combination of placenta previa (placenta over the cervix) and a prior uterine scar especially raises the risk for this invasive placentation. By contrast, placenta previa itself describes placental location without invasion; placental abruption involves premature separation of a normally implanted placenta; and uterine rupture is a full-thickness tear of the uterine wall—serious, but not an invasion of placental tissue into the myometrium.