Long-term outcomes after ovarian tissue cryopreservation and transplantation: more than 20 years of experience in 194 patients.

RESEARCH QUESTION: What are the live birth rate and menstrual recovery rate among women undergoing ovarian tissue cryopreservation (OTC), with or without subsequent ovarian tissue transplantation (OTT), in a large monocentric cohort? DESIGN: This retrospective monocentric cohort study included women who underwent OTC between 1997 and 2024, mainly prior to highly gonadotoxic treatment or, in a few cases, with Turner syndrome, ovarian benign disease leading to bilateral ovariectomy (recurrence of mature teratoma), or borderline tumours. In total, 517 patients underwent OTC and 55 later consulted for potential OTT. All patients were seen in a dedicated fertility preservation clinic. When indicated, OTC was performed. After treatment, outcomes including menstrual resumption and live birth were assessed. RESULTS: At follow-up, 174 patients (34%) were lost and 107 (21%) had died. In the OTC cohort (n = 144, excluding patients who returned for OTT), the mean ± SD age at OTC was 20.6 ± 8.1 years (range 11 months-40 years). Main indications included lymphoma, cerebral cancer, non-haematological and haematological benign disease, haematological cancer, and leukaemia. Among 139 evaluable patients (excluding five patients who underwent bilateral oophorectomy), 92 (66.2%) resumed menstruation. Fifty patients expressed a desire to conceive, and 30 (60%) achieved at least one live birth. Forty-six patients underwent OTT to conceive; 12 conceived naturally within a mean ± SD of 17 ± 8.1 months after transplantation and two following IVF-intracytoplasmic sperm injection. CONCLUSIONS: This experience over >20 years shows that many women recover spontaneous ovarian function and fertility after OTC, while for those who do not, subsequent OTT offers a possibility of restoring both menstruation and fertility, confirming OTC/OTT as an effective long-term strategy for fertility preservation.