Pathophysiology and Management of Placenta Accreta Spectrum

Placenta Accreta Spectrum (PAS) disorders, including placenta accreta, increta, and percreta, are serious obstetric conditions characterized by abnormal placental adherence to the uterine wall. With increasing incidence, PAS poses significant risks, primarily through massive hemorrhage during or after delivery, often necessitating hysterectomy. Key risk factors include prior cesarean sections, uterine surgery, and placenta previa diagnosis. In this review, we will examine the pathophysiology of PAS, with a focus on the mechanisms underlying abnormal trophoblast invasion and defective decidualization. We will highlight the role of uterine scarring, extracellular matrix remodeling, dysregulated signaling pathways, and immune and vascular alterations in disrupting the maternal-fetal interface, ultimately predisposing to morbid placentation and delivery complications. We will also discuss the life-threatening complications of PAS, such as shock and multi-organ failure, which require urgent multidisciplinary intensive care, as well as the optimization of management through preoperative planning and intraoperative blood loss control to reduce maternal morbidity and mortality.