Chemotherapy and fertility.

The overall increase in cancer prevalence and the significant increase in long-term survival have generated worldwide interest in preserving fertility in young women exposed to gonadotoxic chemo- and radiotherapy. Infertility represents one of the main long-term consequences of combination chemotherapy given for lymphoma, leukaemia and other malignancies in young women. The gonadotoxic effect of various chemotherapeutic agents is diverse, may involve a variety of pathophysiologic mechanisms, and is not unequivocally understood. Proliferating cells, such as in tissues with high turnover (i.e. bone marrow, gastrointestinal tract and growing ovarian follicles) are more vulnerable to the toxic effect of alkylating agents. These agents may also be cytotoxic to cells at rest, as they are not cell-cycle specific. Alkylating agents, the most gonadotoxic chemotherapeutic medications, cause dose-dependent, direct destruction of oocytes and follicular depletion, and may bring about cortical fibrosis and ovarian blood-vessel damage. The reported rate of premature ovarian failure after various diseases and chemotherapeutic protocols differ enormously, and depend mainly on the chemotherapeutic protocol used and age range of the woman. Several options have been proposed for preserving female fertility, despite gonadotoxic chemotherapy: ovarian transposition, cryopreservation of embryos, unfertilised metaphase-II oocytes and ovarian tissue, and administration of gonadotropin-releasing hormone agonistic analogs in an attempt to decrease the gonadotoxic effects of chemotherapy by simulating a prepubertal hormonal milieu. None of these methods is ideal and none guarantees future fertility in all survivors; therefore, a combination of methods is recommended for maximising women's chances of future fertility.