Reproductive outcomes following fertility preservation in women with endometriosis

RESEARCH QUESTION: What are the fertility outcomes in women with endometriosis who attempt to conceive at least 2 years after undergoing fertility preservation. DESIGN: This retrospective, observational, bicentric cohort study included women diagnosed with endometriosis confirmed by imaging (pelvic magnetic resonance imaging or ultrasonography) who underwent at least one controlled ovarian stimulation cycle for fertility preservation between 1 July 2013 and 31 December 2019. RESULTS: Among 200 participants, follow-up data were available for 184, of whom 76 (41.3%) had attempted to conceive by the end-point (15 February 2023). The median number of oocytes and/or embryos vitrified per patient was 14 (interquartile range [IQR] 8-20). Being in a relationship at the initial consultation was significantly associated with later conception attempts (70.7% versus 25.7%, P < 0.0001). Overall, 48 (63.2%) achieved a pregnancy: 50% naturally, 37.5% using frozen material, and 12.5% via a new IVF attempt with fresh oocytes. Live birth occurred in 31 (40.8%). Among those who had attempted conception, the 4-year cumulative pregnancy incidence following fertility preservation was estimated at 55% (95% CI 45-68%). The cryopreserved material utilization rate was estimated at 48% (95% CI 37-63%) 5 years after fertility preservation. Nulliparity (hazard ratio [HR] 1.43, 95% CI [1.00-2.06] ) and having frozen embryos (HR 2.34, 95% CI [1.65-3.33]) were significant predictors of material use over the follow-up period. CONCLUSIONS: Despite the known detrimental effects of endometriosis on fertility, a majority of women who attempted to conceive following fertility preservation achieved pregnancy, with a substantial proportion conceiving naturally. Half of these used their cryopreserved material, supporting fertility preservation as part of comprehensive reproductive counselling in endometriosis care.