Fertility preservation in women with cancer: in vitro maturation of oocytes

Immature oocytes are an emerging source of gametes in patients with a diagnosis of cancer who have not enough time to undergo stimulation of their ovaries to obtain mature oocytes for fertility preservation. Immature oocytes can be harvested transvaginally from small antral follicles without hormonal pretreatment, mature in vitro and cryopreserved for future use. Oocytes can also be retrieved from extracorporeal ovarian tissue. After in vitro maturation (IVM), these oocytes can be fertilised and result in live births. The combination of fertility preservation methods may raise the hope of delayed childbearing to an increasing population of young cancer patients who undergo gonadotoxic cancer treatment. The lessons learnt from IVM in animal research and in the fertility clinic should soon transpire into improved efficiency of this approach in the context of oncofertility.