Patterns of and risk factors for recurrence in women with ovarian endometriomas

Objective: To identify risk factors for and the patterns of recurrence of endometrioma and of dysmenorrhea in women with ovarian endometrioma. Methods: We evaluated 710 consecutive patients operated on for ovarian endometriomas who were followed up for an average of 22.4 months. Twenty factors were examined to assess their effect on risk of recurrence of endometrioma and of dysmenorrhea using survival analysis. Hazard rate also was estimated to examine recurrence patterns. Results: For recurrence of endometrioma, the revised American Fertility Society (rAFS) score, younger age at surgery, and previous medical treatment of endometriosis were identified to be risk factors. For recurrence of dysmenorrhea, rAFS score was the only risk factor. For both recurrences, there was a constant hazard rate in the first 28-30 months after surgery, indicating that the recurrence in that period is completely random. After that period, the hazard rate increased dramatically. Conclusion: The total rAFS score, but not rAFS stage, is a risk factor for recurrence of both endometrioma and dysmenorrhea, indicating that the rAFS stage has little prognostic value. The existence of a completely random recurrence period may be a universal phenomenon, with its duration and the magnitude of recurrence risk determined by patient characteristics and quality of care. The second phase of much higher recurrence risk may reflect ectopic endometrium. Therefore, the identification of risk factors as well as patterns of recurrence should shed better light on possible causes for recurrence, which is now poorly understood.