Placenta Percreta with Bladder Invasion: MRI Features of a Rare Case at FIGO Stage 3 Placenta Accreta Spectrum

Abstract

Placenta Accreta Spectrum (PAS) encompasses a continuum of abnormal placental attachment disorders, including placenta accreta, increta, and percreta. These conditions arise from a defective decidual interface that allows excessive trophoblastic invasion into the uterine wall. Among them, placenta percreta represents the most severe manifestation, characterized by complete penetration of the myometrium and uterine serosa, often extending into adjacent pelvic organs such as the urinary bladder. The incidence of PAS has markedly increased over recent decades, largely in parallel with the global rise in cesarean delivery rates and prior uterine surgeries. Other recognized risk factors include placenta previa, advanced maternal age, multiparity, and previous uterine instrumentation such as curettage. Clinically, placenta percreta is associated with catastrophic hemorrhage, massive transfusion requirements, adjacent organ injury, and high maternal morbidity and mortality. Early and accurate prenatal diagnosis is therefore crucial for improving maternal outcomes. Advances in ultrasonography and magnetic resonance imaging (MRI) have enabled more reliable detection of abnormal placental invasion and mapping of its extent, facilitating multidisciplinary surgical planning. Despite these improvements, management of placenta percreta remains complex and controversial, balancing maternal safety, fertility preservation, and surgical risks.