can be performed via traditional slow-freezing or a rapid freezing method referred to as vitrification.
Oocyte cryopreservation can therefore be offered as a standard of care, not only to patients wishing to delay fertility because of imminent cancer therapy but also to couples who refuse embryo cryopreservation
or in countries where there are limits on fresh oocyte fertilisation and where embryo freezing is prohibited.
is an established technique; however, the success rate in terms of live births from frozen embryos is still only around 20% .
Evaluation of the clinical efficacy of embryo cryopreservation
Wallach, "The Social Implications of Embryo Cryopreservation
," (2005) 84 Fertility and Sterility 823; supra note 45; Kimberly Elford, Carol Lawrence & Arthur Leader, "Research Implications of Embryo Cryopreservation
Choices Made by Patients Undergoing in Vitro Fertilization," (2004) 81 Fertility and Sterility 1154.
For women, embryo cryopreservation
is the most effective method, although it entails delaying cancer therapy for 2-6 weeks.
also offers a way to safeguard against unwelcome mutations and inadvertent selection.
With a goal of preventing multiple gestations while maintaining pregnancy rates, the American Society for Reproductive Medicine (ASRM) in conjunction with the Society for Assisted Reproductive Technology (SART) issued voluntary guidelines nearly 7 years ago that recommend maximal numbers of embryos for transfer based on a woman's age, embryo quality, and the opportunity for embryo cryopreservation
During the Rios affair, the Australian Waller Committee "warmly encouraged" the development of freezing techniques for human ova, adding that if the research is successful, the "whole subject" of embryo cryopreservation
should be reviewed.
Self-recrimination, which is already underway during IVF when women evaluate themselves on the basis of the number of follicles or eggs they produce, can be extended and broadened by embryo cryopreservation
In the last few years, advances in cryopreservation methodologies have dramatically improved the efficiency of oocyte cryopreservation, leading to the birth of over a thousand babies and challenging the supremacy of embryo cryopreservation
as the preferred form of fertility preservation.
sup],,,,, Vitrification is superior to slow-freezing in human embryo cryopreservation