Androprotect und Perspektiven der Fertilitätstherapie.

<bold>Background: </bold>Fertility protection is essential for men undergoing potentially gonadotoxic treatment. It is usually offered to adolescents and men in reproductive age by semen cryopreservation. In case of azoospermia, testicular sperm cryopreservation is an additional option. In prepubertal boys no sperm cryopreservation is possible. A purely experimental option is cryopreservation of spermatogonial stem cells in immature testis tissue.<bold>Method: </bold>Transplantation of either immature testis tissue or testicular stem cells or spermatogonia generated in vitro from stem cells are possible options for fertility preservation in boys.<bold>Objectives: </bold>In this article, the rationale for cryopreservation of gonadal stem cells and the experimental methods for refertilization are summarized. The current research, national and international clinical and research activities and possible perspectives of further development of fertility preservation are explained. [ABSTRACT FROM AUTHOR]