Human oocyte cryopreservation (egg freezing) is a procedure to preserve a woman's eggs (oocytes). The eggs are extracted, frozen and stored. The intention of the procedure is that, in the future, the woman may choose to have the eggs thawed, fertilized, and transferred to the uterus as embryos to facilitate a pregnancy.
Egg and ovarian tissue freezing has the potential to help women with cancer, as chemotherapy and radiation treatment can often have a harmful effect on fertility, rendering many of these women menopausal.
Women who are at risk of early menopause, have a genetic disorder that could limit fertility or wish to have children at a later date can also have eggs or ovarian tissue collected and stored.
Some patients taking part in an IVF program have moral or ethical beliefs against freezing supernumerary or excess embryos and may prefer to store unfertilised eggs instead. The ability to cryopreserve eggs before fertilisation means that if they are surplus to requirements in the future, their disposal would not raise some of the moral or ethical dilemmas that the discarding of embryos may.