Placenta Accreta Spectrum: Correlation between FIGO Clinical Classification and Histopathologic Findings

Soroush Aalipour, Bahram Salmanian, Karin A. Fox, Steven Leigh Clark, Amir A. Shamshirsaz, Nazlisadat Meshinchi Asl, Eumenia C. Castro, Hadi Erfani, Jimmy Spinoza, Ahmed Nassr, Michael A. Belfort, Alireza A. Shamshirsaz

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Objective: Placenta accreta spectrum (PAS) covers a wide spectrum of placental adherence/invasion with varied clinical significance. Histopathologic examination is considered the confirmatory gold standard, but is only obtained sometime after definitive treatment. The International Federation of Gynecology and Obstetrics (FIGO) has published a new clinical classification that can be assigned at delivery, and we aimed to investigate the association between this new FIGO classification and histopathology and also to assess its correlation with maternal outcomes. Study Design: We studied a retrospective cohort of 185 patients with histopathologically proven PAS managed at our referral center between September 2012 and January 2019. Two experienced surgeons retrospectively reviewed charts and assigned the FIGO grading based on findings reported at delivery. A third experienced reviewer adjudicated to determine the classification used for final analysis. Categorical outcomes were compared with the use of chi-squared and the Fisher exact test, as appropriate. A multivariate model was designed to adjust outcomes in different FIGO groups for the involvement of a formal multidisciplinary management team. Results: Among 185 patients, there were 41 (22%) placenta accreta, 44 (24%) placenta increta, and 100 (54%) placenta percreta on histopathology. The inter-rater reliability was found to be substantial with Kappa=0.661 (p<0.001), and 95% confidence interval (CI): 0.449-0.872. There was a significant association between all histopathology groupings and the FIGO clinical classification (p<0.001). However, we found no association between FIGO classifications and maternal complications. Conclusion: The new FIGO clinical classification is strongly associated with histopathologic findings. A better understanding of the depth and extent of invasion as afforded by the clinical classification system will help standardize reporting and future research.

Original languageEnglish (US)
Pages (from-to)149-154
Number of pages6
JournalAmerican Journal of Perinatology
Issue number2
StatePublished - Jan 1 2023
Externally publishedYes


  • FIGO classification
  • abnormally invasive placenta
  • antenatal diagnosis
  • depth of invasion
  • morbidly adherent placenta
  • multidisciplinary management
  • placenta accreta
  • placenta accreta spectrum disorder

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Obstetrics and Gynecology


Dive into the research topics of 'Placenta Accreta Spectrum: Correlation between FIGO Clinical Classification and Histopathologic Findings'. Together they form a unique fingerprint.

Cite this