Ovarian transplantation in humans: indications, techniques and the risk of reseeding cancer.

Laboratory research on ovarian cryopreservation and transplantation began in the 1950s leading to clinical studies in the 2000s. The research that was performed during this half century indicated that cryopreserved ovarian tissue has the potential to restore fertility in women who face premature ovarian failure due to chemotherapy, radiotherapy or surgery. To date, ovarian function has been restored in at least four women. Even though no pregnancies have been reported so far from these clinical studies, animal studies indicate that this is a valid prospect for humans. Future clinical trials will determine on a larger number of patients the longevity of ovarian grafts, normality of hormone production and ovarian follicle development, possibility and safety of pregnancy, and the safety of auto-transplantation in cancer patients. However, the major improvement in the efficiency of ovarian transplantation is anticipated to come from research exploring the revascularization process.