Cryopreservation of unfertilized oocytes and ovarian tissue

Abstract

Due to modern cancer therapy, long term survival rates for some childhood cancers and for cancers in young women have become remarkably high. Sadly, this necessary cancer therapy often leaves the survivors infertile.

Men have an option to cryopreserve sperm for later use to regain fertility, while the choices for women and young girls have been limited. After IVF treatment became available, cryopreservation of fertilized oocytes for later use became an option. Many women however, do not have the time to complete an IVF-cycle before starting cancer therapy, some of those who do, do not have a partner to fertilize their oocytes before cryopreservation. In case of young girls, it is ethically challenging to perform hormone stimulation to induce super ovulation. The result is a group of cancer survivors with no true option for fertility preservation.

Although presently considered as an experimental procedure, this emerging technology in cryopreservation of unfertilized mature- and immature oocytes and ovarian tissue, might in the future be the option for fertility preservation these patients have been waiting for.

This paper describes the progress in the field of cryopreservation of unfertilized oocytes and ovarian tissue by presenting some of the work done on animals and humans. It also describes some of the methods used in the processes necessary for cryopreservation and assisted fertilization.

Finally, the paper contains a discussion of some of the benefits and problems that might arise as these future options for fertility preservation become wide-spread.