Clinical limitations of the International Federation of Gynecology and Obstetrics (FIGO) classification of uterine fibroids

Objective: To determine the reproducibility of classifying uterine fibroids using the 2011 International Federation of Gynecology and Obstetrics (FIGO) staging system. Methods: The present retrospective cohort study included patients presenting for the treatment of symptomatic uterine fibroids at the Gynecology Fibroid Clinic at Mayo Clinic, Rochester, USA, between April 1, 2013 and April 1, 2014. Magnetic resonance imaging of fibroid uteri was performed and the images were independently reviewed by two academic gynecologists and two radiologists specializing in fibroid care. Fibroid classifications assigned by each physician were compared and the significance of the variations was graded by whether they would affect surgical planning. Results: There were 42 fibroids from 23 patients; only 6 (14%) fibroids had unanimous classification agreement. The majority (36 [86%]) had at least two unique answers and 4 (10%) fibroids had four unique classifications. Variations in classification were not associated with physician specialty. More than one-third of the classification discrepancies would have impacted surgical planning. Conclusion: FIGO fibroid classification was not consistent among four fibroid specialists. The variation was clinically significant for 36% of the fibroids. Additional validation of the FIGO fibroid classification system is needed.