Recent advances of the egg's freezing: An overview

It is now more than three decades since the first live birth from oocyte cryopreservation. At present, oocyte cryopreservation has become a major component of Assisted Reproductive technologies (ART). Across the world, there is an increasing demand, especially for so-called ‘social egg freezing’ that allows women to preserve their fertility in anticipation of age-related fertility decline. The purpose of this review article was to investigate the current status of oocyte cryopreservation, common techniques, success rate, clinical applications, the rise of elective oocyte cryopreservation, and future implications. A systematic search was performed using Web of Science and PubMed databases for articles published between January 1980 and December 2015. Keywords used included ‘egg freezing’, ‘oocyte freezing’, ‘oocyte cryopreservation’, ‘oocyte vitrification’, and ‘fertility preservation’. Recently, due to many reasons, including resolving age-related infertility in women the success rate of oocyte cryopreservation by vitrification has risen and IVF pregnancy rates are now similar to those achieved by fresh oocytes, therefore a remarkable increase is seen in oocyte cryopreservation cycles around the world. Oocyte cryopreservation (vitrification), especially social egg freezing is one of the best choices in women and girls with cancer who are at risk of losing fertility due to chemotherapy and radiation therapy, reproductive problems, premature ovaries, and also in women with chronic illnesses.