Ovarian endometriosis and fertility preservation: a challenge in 2018.

Endometriosis is a benign, estrogen-dependent gynecological disorder. It is now well established that three different forms of endometriosis can occur in the pelvic cavity, namely peritoneal endometriosis, ovarian endometriosis and deep endometriotic nodules of the rectovaginal septum. Treatment of endometriosis-associated infertility has been investigated using both medical and surgical modalities. Surgery for ovarian endometriosis can lead to premature ovarian insufficiency (POI) and further infertility, so one of the most important goals of therapy should be preserving fertility. Procedures combining stripping and ablation should be considered the first-line approach for ovarian endometrioma-related infertility, in order to protect the ovarian reserve, which may already be depleted even before surgery. Autotransplantation of ovarian tissue should be considered in case of mandatory radical treatment (oophorectomy), or if conservative treatment poses a risk. For patients at risk of POI, particularly those undergoing gonadotoxic treatment, two main fertility preservation options exist: oocyte vitrification or reimplantation of fresh or frozen ovarian tissue. Both have advantages and disadvantages.