Introduction: Male fertility preservation: innovations and questions.

It is now well established that many benign or malignant diseases may by themselves or as result of treatment, impair male fertility. Therefore, preserving the potential of becoming a genetic father represents a major issue. Besides sperm cryopreservation, which is the most reliable method for male fertility preservation, other strategies have more recently emerged, especially in prepubertal boys. Prepubertal germ cell storage from testicular sperm extraction and derivation of male gametes from stem cells may represent a future hope, although raising many ethical issues.