Ovarian reserve, endometriomas, and surgery: research must go on - Fertility and Sterility

In this issue of Fertility and Sterility, Muzii et al. (1x1Muzii, L., Di Tucci, C., Di Feliciantonio, M., Galati, G., Di Donato, V., Musella, A. et al. Anti-mullerian hormone is reduced in the presence of ovarian endometriomas: a systematic review and meta-analysis. Fertil Steril. 2018; 110: 932–940 Google ScholarSee all References)(1) present results of a meta-analysis on the peripheral levels of antimüllerian hormone (AMH) in women carrying ovarian endometriomas. They show that these levels are lower compared to controls thus indirectly suggesting that the reported damage to the ovarian reserve observed after surgery for endometriomas may, at least in part, precedes the intervention (2x2Hamdan, M., Dunselman, G., Li, T.C., and Cheong, Y. The impact of endometrioma on IVF/ICSI outcomes: a systematic review and meta-analysis. Hum Reprod Update. 2015; 21: 809–825 Google ScholarSee all References)(2). These results are of great interest and solve a long-standing controversy, but they must be interpreted cautiously and within a more comprehensive vision of the argument. Most relevant is the need to keep these findings within the boundaries of research without inferring undue and simplistic clinical recommendations. This study shows that serum AMH is lower in women with endometriomas. It does not demonstrate that ovarian reserve is injured in women with ovarian endometriomas. Indeed, one may speculate that the presence of these cysts may not be directly detrimental to the ovarian reserve but, conversely, may only perturb the physiology of the ovary causing a transient derangement of the complex and unknown mechanisms regulating AMH production. Moreover, one should also consider the important effects on local vascularization caused by the presence of large endometriomas. AMH could be normally produced in affected ovaries but may encounter more difficulties to reach the peripheral circulation. To note, AMH is a paracrine factor and not a hormone (to date there is no convincing evidence of a systemic role of AMH): an impairment of the processes leading to AMH secretion into the peripheral circulation is not compensated by feedback mechanisms. In other words, to date, we do not have sufficient evidence to speculate that the reduced serum AMH in women with endometriomas reflects a real and definitive damage to the ovarian reserve rather than only a transient and potentially reversible interference with ovarian physiology. In this context, it would be also of utmost interest obtaining data on the role of time, i.e. on the role of the age of the endometriomas on