Which is the most concerning obstetric complication associated with placenta previa and prior cesarean deliveries?

• A. Placenta accreta
• B. Placenta previa
• C. Placental abruption
• D. Vasa previa

Answer: (A)

When placenta previa coexists with uterine scarring from prior cesarean deliveries, the placenta is more likely to implant into or invade the scarred myometrium, a situation known as placenta accreta spectrum. The scarred area disrupts the normal decidual layer, allowing placental villi to attach directly to the myometrium rather than the normal placental bed. This leads to a placenta that cannot separate properly after delivery, causing massive postpartum hemorrhage. Because this bleeding is often uncontrollable without major intervention, placenta accreta frequently necessitates hysterectomy to save the mother’s life, making it the most concerning complication in this scenario.

Placenta previa itself describes the placenta covering the cervical opening and explains the bleeding risk, but the more dangerous issue here is the abnormal placentation that can follow a prior cesarean. Placental abruption involves premature separation of a normally implanted placenta and is another obstetric emergency, but it’s not as specifically linked to prior cesarean scars as placenta accreta. Vasa previa involves fetal vessels crossing the cervix and is a distinct but less likely concern in this particular combination.