Placenta Accreta Spectrum Disorders: Current Perspectives on Epidemiology, Diagnosis, and Management
Keywords:
Placenta accreta spectrum, abnormally invasive placenta, placenta previa, cesarean delivery, prenatal ultrasound diagnosis, magnetic resonance imaging, maternal hemorrhage, cesarean hysterectomy, conservative management, maternal morbidity, trophoblast invasion, FIGO classificationAbstract
Placenta accreta spectrum (PAS) disorders represent life-threatening obstetric complications characterized by abnormal placental adherence to or invasion through the uterine myometrium and adjacent structures. First systematically described by Irving and Hertig in 1937, PAS has transformed from an exceptionally rare condition occurring in approximately 1 in 30,000 deliveries to a major public health concern with current incidence rates of 1 in 300-500 deliveries. This dramatic 10-fold increase over the past four decades directly correlates with rising global cesarean delivery rates, establishing PAS as a predominantly iatrogenic complication of modern obstetric practice. The condition encompasses a spectrum of severity: placenta accreta (Grade 1), where chorionic villi attach directly to myometrium without intervening decidua; placenta increta (Grade 2), involving invasion into myometrial depth; and placenta percreta (Grade 3), characterized by penetration through the uterine serosa with potential invasion of bladder or other pelvic organs. PAS is associated with severe maternal morbidity including massive hemorrhage requiring extensive blood transfusion, emergency hysterectomy resulting in fertility loss, urologic and bowel injuries, intensive care unit admission, and maternal mortality rates reaching 7% in some series. The combination of placenta previa with prior cesarean delivery constitutes the highest risk profile, with PAS occurrence escalating from 3% after one cesarean to 67% after five or more procedures. Despite advances in prenatal imaging and multidisciplinary management, population-based studies reveal that approximately 50% of cases remain undiagnosed before delivery, contributing to preventable maternal morbidity and mortality. This review synthesizes current evidence on PAS pathophysiology, epidemiology, standardized classification systems, prenatal diagnostic strategies, and evidence-based management approaches to optimize maternal and neonatal outcomes.