Factors Influencing the Timing of Ovarian Tissue Cryopreservation in Young Girls.

The aim of this study was to identify pitfalls in ovarian tissue cryopreservation protocol from referral to surgical procedure and to analyze factors associated with chemotherapy exposure of the cryopreserved tissue and decreased ovarian function in a cohort of young girls at high risk of infertility. The study population comprised 200 girls eligible for ovarian tissue cryopreservation between 2002 and 2020 at the Children's Hospital of the University Central Hospital of Helsinki (Finland). Analyses included evaluation of the proportion of patients who underwent ovarian tissue cryopreservation, factors associated with patient selection and timing of ovarian tissue cryopreservation, and ovarian function during long-term follow-up in relation to oncological treatments. Lack of counselling was identified as the major reason for not receiving ovarian tissue cryopreservation. A longer interval from scheduling gonadotoxic therapy to cryopreservation correlated with a higher exposure to alkylating agents of the ovarian tissue. The long-term ovarian function was mainly influenced by age at the time of gonadotoxic treatment. Current selection criteria for ovarian tissue cryopreservation should be implemented in order to stratify patients at risk of infertility and timely identify those at higher risk, especially in relation to age and pubertal stage. Efforts to increase healthcare providers' awareness and facilitate guided timing in relation to the treatment protocols are needed to guarantee early access to ovarian tissue cryopreservation for all patients at high risk of infertility.