Placenta Accreta Spectrum: A Comprehensive Review of Guidelines.

Importance: Placenta accreta spectrum (PAS) represents a range of disorders characterized by abnormal placental invasion and is associated with severe maternal morbidity and mortality.

Objective: The aim of this study was to review and compare the most recently published major guidelines on the diagnosis and management of this potentially life-threatening obstetric complication.

Evidence acquisition: A descriptive review of guidelines from the American College of Obstetricians and Gynecologists, the Royal Australian and New Zealand College of Obstetricians and Gynecologists, the International Society for Abnormally Invasive Placenta, the Royal College of Obstetricians and Gynecologists, the International Federation of Gynecology and Obstetrics, and the Society of Obstetricians and Gynecologists of Canada on PAS disorders was carried out.

Results: There is a consensus among the reviewed guidelines regarding the definition and the diagnosis of PAS using specific sonographic signs. In addition, they all agree that the use of magnetic resonance imaging should be limited to the evaluation of the extension to pelvic organs in case of placenta percreta. Moreover, American College of Obstetricians and Gynecologists, Royal College of Obstetricians and Gynecologists, International Federation of Gynecology and Obstetrics, and the Society of Obstetricians and Gynecologists of Canada agree that screening for PAS disorders should be based on clinical risk factors along with sonographic findings. Regarding management, they all highlight the importance of a multidisciplinary team approach and recommend delivery by elective cesarean section at a tertiary center with experienced staff and appropriate resources. Routine preoperative ureteric stenting and occlusion of pelvic arteries are universally not recommended. Moreover, hysterectomy following the delivery of the fetus, expectant management with placenta left in situ, and conservative management in case of focal disease and desired fertility are all considered as acceptable treatment options. The reviewed guidelines also suggest some measures for intraoperative and postoperative hemorrhage control and recommend prophylactic administration of antibiotics. Methotrexate after expectant management is unanimously discouraged. On the other hand, there is no common pathway with regard to the optimal timing of delivery, the recommended mode of anesthesia, the preferred skin incision, and the effectiveness of the delayed hysterectomy approach.

Conclusions: PAS disorders are mainly iatrogenic conditions with a constantly rising incidence and potentially devastating consequences for both the mother and the neonate. Thus, the development of uniform international practice protocols for effective screening, diagnosis, and management seems of paramount importance and will hopefully drive favorable pregnancy outcomes.