Improving placenta accreta spectrum diagnosis: impact of structured imaging protocols and multidisciplinary review in a tertiary service evaluation and re-audit

Thomas Chadwick; Saloma Gomez; Bode Williams

doi:10.51496/jogm.v5.331

Authors

Thomas Chadwick Liverpool Women’s Hospital, NHS University Hospitals of Liverpool Group, Liverpool, UK
Saloma Gomez Liverpool Women’s Hospital, NHS University Hospitals of Liverpool Group, Liverpool, UK
Bode Williams Liverpool Women’s Hospital, NHS University Hospitals of Liverpool Group, Liverpool, UK

DOI:

https://doi.org/10.51496/jogm.v5.331

Keywords:

placenta accreta spectrum, placenta, diagnostic accuracy, ultrasound, mri, multidisciplinary team, obstetric imaging, maternal outcomes, service evaluation

Abstract

Objective: The study aims to assess the impact of targeted diagnostic and organisational interventions on placenta accreta spectrum (PAS) screening performance in a tertiary referral centre.

Design: Retrospective comparative audit.

Setting: Liverpool Women’s Hospital, UK.

Methods: PAS screening outcomes from two periods (2017–2020 vs. 2022–2024) were compared. Interventions included standardised ultrasound reporting using the ISUOG proforma, dedicated placental imaging protocols, regional multidisciplinary team (MDT) review, enhanced sonographer training, and selective magnetic resonance imaging (MRI) in indeterminate cases. Screening sensitivity, specificity, predictive values, and diagnostic accuracy were calculated. Ultrasound features associated with true and false positive diagnoses were analysed, and the role of serial scans was assessed.

Results: A total of 60 and 146 patients were screened in the first and second audit periods, respectively. Sensitivity improved from 60.0 to 92.3%, with a modest decrease in specificity from 100.0 to 94.0%. High-yield sonographic signs included bladder line disruption and bladder bulge (positive predictive value [PPV] 100%). Subplacental hypervascularity and lacunae had lower specificity (PPV 53–56%). Serial scanning improved sensitivity (from 69.2 to 92.3%) and accuracy (from 90.4 to 93.8%). False positives were more common with high- or low-lying placentas compared to placenta previa.

Conclusions: Structured imaging protocols, serial scan review, and regional MDT collaboration significantly enhanced PAS detection, supporting safer delivery planning and improved maternal–neonatal outcomes. Future priorities include expanding specialist capacity, formalising care coordination, and implementing real-time data collection to sustain diagnostic gains and progress toward Level 3 PAS surgical centre capability.

Metrics

Metrics Loading ...

References

Jauniaux E, Ayres-de-Campos D, Langhoff-Roos J, Fox KA, Collins S. FIGO classification for the clinical diagnosis of placenta accreta spectrum disorders. Int J Gynecol Obstetr 2019; 146(1): 20–4. doi: 10.1002/ijgo.12761 DOI: https://doi.org/10.1002/ijgo.12761

Jauniaux ERM, Alfirevic Z, Bhide AG, Belfort MA, Burton GJ, Collins SL, et al. Placenta praevia and placenta accreta: diagnosis and management. BJOG 2019; 126(1): 10–11, 22–36. doi: 10.1111/1471-0528.15306 DOI: https://doi.org/10.1111/1471-0528.15306

Di Mascio D, Calì G, D’antonio F. Updates on the management of placenta accreta spectrum. Minerva Ginecol 2019; 71(2): 113–20. doi: 10.23736/S0026-4784.18.04333-2 DOI: https://doi.org/10.23736/S0026-4784.18.04333-2

Hull AD, Moore TR. Multiple repeat cesareans and the threat of placenta accreta: incidence, diagnosis, management. Clin Perinatol 2011; 38(2): 285–96. doi: 10.1016/j.clp.2011.03.010 DOI: https://doi.org/10.1016/j.clp.2011.03.010

Jauniaux E, Jurkovic D. Placenta accreta: pathogenesis of a 20th century iatrogenic uterine disease. Placenta 2012; 33(4): 244–51. doi: 10.1016/j.placenta.2011.11.010 DOI: https://doi.org/10.1016/j.placenta.2011.11.010

Self A, Cavallaro A, Collins SL. Placenta accreta spectrum: imaging and diagnosis. Obstetr Gynaecol 2025; 27(1): 15–28. doi: 10.1111/tog.12956 DOI: https://doi.org/10.1111/tog.12956

Jauniaux E, Bhide A. Prenatal ultrasound diagnosis and outcome of placenta previa accreta after cesarean delivery: a systematic review and meta-analysis. Am J Obstet Gynecol 2017; 217(1): 27–36. doi: 10.1016/j.ajog.2017.02.050 DOI: https://doi.org/10.1016/j.ajog.2017.02.050

Finazzo F, D’antonio F, Masselli G, Forlani F, Palacios-Jaraquemada J, Minneci G, et al. Interobserver agreement in MRI assessment of severity of placenta accreta spectrum disorders. Ultrasound Obstetr Gynecol 2020; 55(4): 467–73. doi: 10.1002/uog.20381 DOI: https://doi.org/10.1002/uog.20381

Kapoor H, Hanaoka M, Dawkins A, Khurana A. Review of MRI imaging for placenta accreta spectrum: pathophysiologic insights, imaging signs, and recent developments. Placenta 2021; 104: 31–9. doi: 10.1016/j.placenta.2020.11.004 DOI: https://doi.org/10.1016/j.placenta.2020.11.004

Shamshirsaz AA, et al. Outcomes of planned compared with urgent deliveries using a multidisciplinary team approach for morbidly adherent placenta. Obstetr Gynecol 2018; 131(2): 234–41. doi: 10.1097/AOG.0000000000002442 DOI: https://doi.org/10.1097/AOG.0000000000002666

Pinto PV, Freitas G, Vieira RJ, Aryananda RA, Nieto-Calvache AJ, Palacios-Jaraquemada JM. Placenta accreta spectrum disorder: a systematic review and meta-analysis on conservative surgery. Int J Gynecol Obstetr 2025. doi: 10.1002/ijgo.70322 DOI: https://doi.org/10.1002/ijgo.70322

Silver RM, et al. Centre of excellence for placenta accreta. Am J Obstet Gynecol 2015; 212(5): 561–8. doi: 10.1016/j.ajog.2014.11.018 DOI: https://doi.org/10.1016/j.ajog.2014.11.018

Collins SL, et al. Proposal for standardized ultrasound descriptors of abnormally invasive placenta (AIP). Ultrasound Obstetr Gynecol 2016; 47(3): 271–5. doi: 10.1002/uog.14952 DOI: https://doi.org/10.1002/uog.14952

Adu-Bredu TK, et al. A simple guide to ultrasound screening for placenta accreta spectrum for improving detection and optimizing management in resource limited settings. Int J Gynecol Obstetr 2023; 160(3): 732–41. doi: 10.1002/ijgo.14376 DOI: https://doi.org/10.1002/ijgo.14376

Alfirevic Z, Tang A-W, Collins SL, Robson SC, Palacios-Jaraquemada J. Pro forma for ultrasound reporting in suspected abnormally invasive placenta (AIP): an international consensus. Ultrasound Obstetr Gynecol 2016; 47(3): 276–8. doi: 10.1002/uog.15810 DOI: https://doi.org/10.1002/uog.15810