Most children treated for cancer can now expect to be cured and to be fertile. However, in a significant minority, future fertility may be compromised by their disease or its treatment.1Although the primary objective of treating cancer is cure, this should be seen in the context of promoting and protecting the child's overall wellbeing. Infertility may have significant psychological consequences in adulthood, and strategies aimed at ameliorating this “cost of cure” provide new challenges to professionals in many different disciplines.

Cryopreservation of semen is well established for sexually mature boys,2 but there are currently few options for peri- or prepubertal children. The use of donated gametes, sperm or eggs, has recently become a realistic possibility in many centres and provides an option if treatment has provoked premature ovarian failure or azoospermia. Finally, gametes, germ cells, and tissues can be collected and stored with the ultimate aim of enabling an individual to become a parent of a child that is genetically theirs. Possibilities for safeguarding future fertility vary from no medical intervention to invasive procedures carrying more than negligible risk in order to harvest gonadal tissue. It is also important to recognise that although young cancer survivors are less likely to have children, this is not solely a result of infertility. Many are unable to form long standing peer relationships, others fear relapse of their disease, and some fear the prospect of leaving their child parentless.3 ,4

Rapid developments in assisted reproduction techniques (ART) now raise the possibility of cryopreserving gonadal tissue to conserve the fertility of young cancer patients. These advances raise major practical, scientific, and ethical issues which are addressed in this and a subsequent article.