O-225 Endometrioma and fertility preservation: how can we save the oocytes?

Abstract Endometriosis is a benign estrogen-dependent disease In the ovary, endometrioma formation may cause local inflammation, giving rise to structural alterations to the ovarian cortexwhich manifest as massive fibrosis and loss of cortex-specific stroma that maintains follicular nests. Subsequent dysregulation of folliculogenesis results in “burn out” of the stockpile of dormant follicles. Moreover, endometriomas contain much higher concentrations of free iron, reactive oxygen species (ROS) and proteolytic enzymzes which could reach adjacent ovarian tissue and lead to follicular loss and intraovarian vascular injury. Fertility preservation is a major challenge when therapeutic approaches of ovarian endometrioma are contemplated. Surgery is often proposed in cases of endometrioma more than 3 cm in size but there are two main risks associated with the surgical treatmant of endometrioma : 1. the risk of excessive surgery (removal or destruction of normal ovarian cortex together with the endometrioma pseudocapsula).Close the ovarian hilus, ovarian tissue removed with the endometrioma wall contained follicles in more than 60% of cases in a study of Muzii and some meta-analyses have revealed significant decreases in AMH after excision. 2. The risk of incomplete surgery with subsequent early recurrence. A correct surgical approach is therefore the first step to preserve oocytes and several techniques are discussed. How to preserve fertility in women at risk of premature ovatian insufficiency (POI) due to severe and/or recurrent ovarian endometriosis? Two main options are currently available : 1. COS,ovum pick-up and vitrification of oocytes is an important fertility preservation approach. Cobo et all published several series and reported high cumulative live birth rates in women less than 35 years, suggesting that patients with endometrioma should be encouraged to freeze oocytes at a younger age. 2. In some circonstances, orthotopic autotransplantation of cryopreserved ovarian cortex (which has led to more than 200 live births ) could be proposed to maintain the follicular pool.