Fertility preservation in girls and young women.

There is increasing interest and experience in the options available to preserve fertility in those about to undergo potentially gonadotoxic chemotherapy or radiation therapy, usually related to treatment for cancer. Recent years have seen the development of methods for prepubertal girls, female adolescents and adult women, although these remain less established than sperm cryopreservation for men. At present, the options for prepubertal boys remain experimental. Embryo cryopreservation following ovarian stimulation and IVF is a routine procedure technically and its success in the management of infertility is established. However, there are no data on uptake or success rates in the context of fertility preservation in women with cancer. Oocyte cryopreservation is technically challenging and requires ovarian stimulation, thus potentially resulting in a delay in cancer treatment. Oocyte vitrification offers increased success rates in comparison with slow freezing; however, this approach is also limited by the number of oocytes that can be obtained. The third possibility, ovarian tissue cryopreservation, can be performed without significant delay and is the only option for prepubertal girls. Worldwide, a small number of children have been born following reimplantation of frozen/thawed ovarian tissue. It is clear that fertility preservation is important for some girls and young women facing treatments that will compromise their fertility, but the availability of all approaches varies widely. Effective approaches for prepubertal boys are also required.