Oocyte cryopreservation entails important potential advantages for human
IVF, offering a less ethically disputable alternative to embryo cryopreservation,
simplifying and making safer oocyte donation, and giving an opportunity for
fertility preservation to women at risk of premature ovarian failure as an effect
of genetic factors or chemo- or radiotherapies. Oocyte cryopreservation could
also meet the expectations of women wishing to preserve their fertility for
social reasons. 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. This text has been conceived with the aim of offering a comprehensive view of the state of the art of oocyte cryopreservation. It covers fundamental concepts of low temperature storage (controlled rate slow cooling and
vitrification), aspects of oocyte physiology relevant to the process of
cryopreservation, essential biological and clinical evidence, and ethical
implications of oocyte cryopreservation, thereby providing a complete
overview of progress in this strategy in assisted reproduction.

Oocyte cryopreservation entails important potential advantages for human
IVF, offering a less ethically disputable alternative to embryo cryopreservation,
simplifying and making safer oocyte donation, and giving an opportunity for
fertility preservation to women at risk of premature ovarian failure as an effect
of genetic factors or chemo- or radiotherapies. Oocyte cryopreservation could
also meet the expectations of women wishing to preserve their fertility for
social reasons. 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. This text has been conceived with the aim of offering a comprehensive view of the state of the art of oocyte cryopreservation. It covers fundamental concepts of low temperature storage (controlled rate slow cooling and
vitrification), aspects of oocyte physiology relevant to the process of
cryopreservation, essential biological and clinical evidence, and ethical
implications of oocyte cryopreservation, thereby providing a complete
overview of progress in this strategy in assisted reproduction.