The effect of surgery for endometrioma on ovarian reserve evaluated by antral follicle count: a systematic review and meta-analysis

STUDY QUESTION: Does surgical treatment of endometriomas impact on the ovarian reserve as evaluated with antral follicle count (AFC)? SUMMARY ANSWER: This meta-analysis of published data shows that surgery for endometrioma does not significantly affect ovarian reserve as evaluated by AFC. WHAT IS KNOWN ALREADY: Surgical excision of an ovarian endometrioma significantly affects ovarian reserve evaluated with anti-Mullerian hormone (AMH) levels. Data for other reliable markers of ovarian reserve, such as AFC, have not been pooled in meta-analyses. STUDY DESIGN, SIZE, DURATION: Asystematic review with electronic searches of PubMed, MEDLINE and Embase up to April 2014 was conducted to identify articles evaluating AFC before and after surgery for ovarian endometriomas, or before or after surgery for the affected versus the contralateral ovary. PARTICIPANTS/MATERIALS, SETTING, METHODS: Of the 24 studies evaluated in detail, 13 were included for data extraction and meta-analysis, including a total of 597 patients. The primary outcome at pooled analysis was AFC (mean and SD) for affected ovaries before and after surgery. Secondary outcomes were AFC for the affected ovary versus the contralateral ovary before surgery, and AFC for the operated versus the contralateral ovary after surgery. The data were pooled using the RevMan software by the Cochrane Collaboration. Heterogeneity between studies was based on the results of the x(2) and I-2 statistics. A random-effect model was used for the meta-analysis because of high heterogeneity between studies. MAIN RESULTS AND THE ROLE OF CHANCE: AFC for the operated ovary did not change significantly after surgery (mean difference 0.10, 95% CI 21.45 to 1.65; P = 0.90). Lower AFC for the diseased ovary compared with the contralateral one was present before surgery, although the difference was not significant (mean difference 22.79, 95% CI 27.10 to 1.51; P = 0.20). After surgery, the operated ovary showed a significantly lower AFC compared with the contralateral ovary (mean difference -1.40, 95% CI -2.27 to -0.52; P = 0.002). LIMITATIONS, REASONS FOR CAUTION: Heterogeneity among the selected studies was high; therefore, limiting the conclusions of the present systematic review. WIDER IMPLICATIONS OF THE FINDINGS: Ovarian reserve evaluated with AFC is not reduced after surgical treatment of an endometrioma. A lower AFC is present for the affected ovary both before and after surgery. Recently, concerns have been raised as to the reliability of AMH as a marker of ovarian reserve. Based on the present findings, surgical treatment of an endometrioma may be considered safer for the ovarian reserve than previously thought. STUDY FUNDING/COMPETING INTERESTS: No external funding was sought or obtained for this study. No conflicts of interest are declared.