Spontaneous antral follicle formation and metaphase II oocyte from a non-stimulated prepubertal ovarian tissue xenotransplant.

[severe combined immunodeficiency]

Current strategies in cancer treatment have markedly increased the rates of remission and survival for cancer patients , but are often associated with subsequent sterility . While there are various options available to an adult female depending on the patient 's particular situation , the only realistic option for preserving fertility in prepubertal females is to cryopreserve ovarian tissue . This is the first report of a morphologically mature oocyte collected from non-stimulated prepubertal ovarian tissue xenotransplants .Ovarian tissue from a 6 Â year old patient suffering from nephroblastoma was removed and cryopreserved for fertility preservation . The frozen-thawed ovarian tissue fragments were xenotransplanted to bilaterally oophorectomized severe combined immunodeficiency (SCID ) mice to assess follicle development .Antral follicle formation occurred post-xenotransplantation in a single ovarian fragment without exogenous hormone stimulation . A morphologically maturing oocyte was harvested from these follicles .Prepubertal human ovarian follicles and oocytes can be matured after xenotransplantation even without exogenous hormone stimulation . These results indicate that tissue collected from prepubertal patients can support fertility in cancer survivors .