When to cryopreserve ovarian tissue: Determining the effects of chemotherapy on the ovarian reserve by studying follicular density and apoptosis

Objectives: Patients scheduled to receive chemotherapy should be counselled on fertility preservation. Known gonadotoxic chemotherapies such as alkylating agents have a high risk of altering ovarian reserve. In some cases, the urgency of treatment requires the use of chemotherapy before fertility preservation, which will be carried out at a later stage. Usually the ovarian tissue is cryopreserved. The aim of our study is to investigate the impact of chemotherapies on follicular density and the apoptosis of reserve follicles. Methods: We included 140 patients: 63 patients, mean age 18.8 years, were included in the group "no chemotherapy " (group A) and 77 patients, mean age 17.1 years, in the group "received chemotherapy before ovarian conservation " (group B). None of the patients had had pelvic radiotherapy prior to ovarian cryopreservation. The histological parameters studied were follicular density and the presence of malignant cells. We selected 12 patients from group A and 15 patients from group B, comparable in age and pathology, for whom we evaluated follicle apoptosis by immunostaining cleaved caspase-3. Results: We demonstrated an inverse relationship between follicular density and age (p < 0.0001), as well as a lack of effect of chemotherapy on follicular density (p = 0.87). We showed the impact of various chemotherapies, especially with alkylating agents, on the apoptosis of ovarian follicles (p < 0.0001). Three patients had ovarian tissue infiltration, two of which were malignant. Conclusion: This work underlines the fact that conservation of ovarian tissue after chemotherapy remains possible.