Which scenario is most likely to increase the risk of placenta accreta?

• A. Advanced maternal age
• B. Multiparity with 2 or more prior cesarean sections
• C. Placenta previa
• D. Fetal anomalies

Answer: (C)

Abnormal placental invasion into the myometrium happens when the decidual layer that normally supports and limits placental attachment is defective. Placenta previa is the scenario that most strongly creates this situation because the placenta implants low in the uterus, over the cervix, where the decidua is often thin or absent and scar tissue from prior uterine surgeries is common. That combination allows placental villi to attach to or invade into the myometrium more easily, leading to accreta. While advanced maternal age and multiple prior cesarean sections increase risk, placenta previa provides the strongest single scenario for accreta to develop. Fetal anomalies are not typically a risk factor.