ftentimes, couples have excess embryos after an In Vitro Fertilization (IVF) cycle that have been cryopreserved for future use. Embryo cryopreservation has become a routine practice within advanced reproductive technology (ART) clinics. The newer technology for embryo cryopreservation, called vitrification, has significantly improved the pregnancy outcomes achieved with frozen embryos compared to the older freezing methods. In fact, success rates with frozen embryo transfer cycles are now equal in success rates compared to fresh embryo transfer cycles.