Cryopreservation of Oocytes and Embryos in Human Assisted Reproduction

Cryopreservation has become an integral component of assisted reproductive technology. The ability to cryopreserve, thaw, and establish pregnancies with supernumerary preimplantation embryos has become an important tool in fertility treatment. Human oocyte cryopreservation has practical application in preserving fertility for individuals prior to cancer treatments. While the efficiency of oocyte and embryo freezing technology has increased over time, there is still room for improvement, since even under ideal circumstances the clinical pregnancy rate from frozen embryo transfer is approximately two-thirds of that from the fresh transfer of embryos. Thus, studies connected with cryopreservation of human oocytes and embryos are very important to the expansion of effective clinical services. This review gives a summary of the theoretical and technical aspects of oocyte and embryo cryopreservation.