Cryopreservation-Vitrification

Cyropreservation is a process where egg, embryos or sperm are preserved by cooling to sub-zero temperatures, typically in liquid nitrogen (-196°C), for whatever period of time is designated by the patients. Cryopreservation is used in infertility programs to freeze and store sperm, eggs or to freeze "leftover" embryos from an in vitro fertilization cycle. The Vitrification of embryos is utilized when the number of embryos produced during any IVF cycle exceeds the number of embryos that are transferred into the uterus. Embryos can be subsequently thawed and placed into the uterine cavity after many years of being frozen. By doing so, one can avoid repeating the entire stimulation and egg retrieval process for future attempts.