Prospects for oocyte banking and in vitro maturation.

Abstract

There is little debate about the desirability of human oocyte ("egg") banking but plenty of discussion about its prospects. Egg banking is needed by young cancer patients before they undergo potentially sterilizing treatment and is a desirable alternative to in vitro fertilization and embryo cryopreservation. However, egg banking is inefficient-oocytes are sensitive to chilling, often fail to survive freeze-thawing, and are susceptible to cytoskeletal damage and aneuploidy. Currently, even the most optimistic success rates offer patients only a slim chance of pregnancy if few oocytes are available. Ultra-rapid freezing with vitrification may offer advantages over conventional equilibrium cooling protocols and needs to be investigated further. Likewise, freezing immature oocytes followed by in vitro maturation offers practical and theoretical advantages, but this method is still inefficient. Nevertheless, all these technologies are improving, and egg banking will eventually become an option for patients seeking fertility preservation.