this is the technique of deep freezing and storing embryos, acolytes and/or sperm cells, and takes place in liquid nitrogen at -196 degrees Celsius.
To avoid the risk of multiple pregnancies good clinics recommend the transfer of one or two well developed embryos. Usually, with a high degree of probability, this yields to a pregnancy. If several blast cysts have been developed, each carrying a high likelihood of success, then the surplus embryos can be cryopreserved. These then can be transferred, at a later date, without preceding stimulation and punctuation into the ovaries.
Under the restrictions of the Fertility Medicine Act of 1992, Cryo-consesved embryos can be stored to 10 years. Ovarian cells and sperm cells that have not been impregnated can be stored lifelong.