PRENATAL DIAGNOSIS: Edited by Jane ChuehPrenatal diagnosis of placenta accreta spectrumConturie, Charlotte L.; Lyell, Deirdre J. Author Information The Department of Obstetrics and Gynecology and the Division of Maternal-Fetal Medicine, Stanford University School of Medicine, Stanford, California, USA Correspondence to Charlotte L. Conturie, MD, Center for Academic Medicine, Obstetrics & Gynecology | MC 5317, Stanford University School of Medicine, 453 Quarry Road, Palo Alto, CA 94304, USA. Tel: +1 650 709 3424; e-mail: [email protected] Current Opinion in Obstetrics and Gynecology: April 2022 - Volume 34 - Issue 2 - p 90-99 doi: 10.1097/GCO.0000000000000773 Buy Metrics Abstract Purpose of review Placenta accreta spectrum (PAS) is a major cause of severe maternal morbidity. Perinatal outcomes are significantly improved when PAS is diagnosed prenatally. However, a large proportion of cases of PAS remain undiagnosed until delivery. Recent findings The prenatal diagnosis of PAS requires a high index of suspicion. The first step is identifying maternal risk factors. The most significant risk factor for PAS is the combination of a prior caesarean delivery and a placenta previa. Other major risk factors include a prior history of PAS, caesarean scar pregnancy (CSP), uterine artery embolization (UAE), intrauterine adhesions (Asherman syndrome) and endometrial ablation. Ultrasound is the preferred imaging modality for the prenatal diagnosis of PAS and can be highly accurate when performed by a provider with expertise. PAS can be diagnosed on ultrasound as early as the first trimester. MRI may be considered as an adjunct to ultrasound imaging but is not routinely recommended. Recent consensus guidelines outline the ultrasound and MRI markers of PAS. Summary Patients with major risk factors for PAS warrant dedicated ultrasound imaging with a provider experienced in the prenatal diagnosis of PAS. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.