Placenta accreta spectrum

A 36-year-old with three previous caesareans is booked for her fourth. The sonographer's report says "anterior placenta praevia, some lacunae, clear zone not well seen". That single line is the whole topic: her risk of accreta spectrum is roughly 40%, and whether she leaves theatre with a uterus — or leaves at all — is largely decided in the six weeks before the operating list.^[8][15]

Overview and definition

The normal third stage works because a plane exists. The decidua basalis is a shear layer that lets the placenta peel away, and myometrium then retracts onto the wound. In accreta spectrum that layer is absent, so there is nothing to peel.^[12][7]

• The lesion: loss of the decidua basalis and of the sonographic "clear zone" between placenta and myometrium, almost always over a previous caesarean scar.^[12][13]
• The consequence: the placenta stays attached, the uterus cannot clamp its own vessels, and any attempt at removal tears a hypervascular bed that is fed by expanded collaterals.^[7][5]
• The names: morbidly adherent placenta and abnormally invasive placenta are the historical synonyms. FIGO settled on placenta accreta spectrum to stop three literatures describing one disease.^[6][2]

References20ShowHide

1. [1]Jauniaux E, Bhide A, Hussein AM, et al. Placenta Praevia and Placenta Accreta Spectrum: Diagnosis and Management: Green-Top Guideline No. 27a BJOG, 2026.PMID 42374711
2. [2]Jauniaux E, Chantraine F, Silver RM, et al. FIGO consensus guidelines on placenta accreta spectrum disorders: Epidemiology Int J Gynaecol Obstet, 2018.PMID 29405321
3. [3]Jauniaux E, Bhide A, Kennedy A, et al. FIGO consensus guidelines on placenta accreta spectrum disorders: Prenatal diagnosis and screening Int J Gynaecol Obstet, 2018.PMID 29405319
4. [4]Sentilhes L, Kayem G, Chandraharan E, et al. FIGO consensus guidelines on placenta accreta spectrum disorders: Conservative management Int J Gynaecol Obstet, 2018.PMID 29405320
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10. [10]D'Antonio F, Iacovella C, Bhide A Prenatal identification of invasive placentation using ultrasound: systematic review and meta-analysis Ultrasound Obstet Gynecol, 2013.PMID 23943408
11. [11]D'Antonio F, Iacovella C, Palacios-Jaraquemada J, et al. Prenatal identification of invasive placentation using magnetic resonance imaging: systematic review and meta-analysis Ultrasound Obstet Gynecol, 2014.PMID 24515654
12. [12]Jauniaux E, Jurkovic D Placenta accreta: pathogenesis of a 20th century iatrogenic uterine disease Placenta, 2012.PMID 22284667
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18. [18]Zuckerwise LC, Craig AM, Newton JM, et al. Outcomes following a clinical algorithm allowing for delayed hysterectomy in the management of severe placenta accreta spectrum Am J Obstet Gynecol, 2020.PMID 31469990
19. [19]Holmes VJ, Skinner S, Silagy M, et al. Changes in practice and management of placenta accreta spectrum disorder: A 20-year retrospective cohort study Aust N Z J Obstet Gynaecol, 2023.PMID 37345840
20. [20]Morel O, van Beekhuizen HJ, Braun T, et al. Performance of antenatal imaging to predict placenta accreta spectrum degree of severity Acta Obstet Gynecol Scand, 2021.PMID 33811333