Semen specimens are usually produced by masturbation into a small sterile container. During the standard course of infertility treatment, hormones are used to stimulate the development of multiple eggs. After these eggs are retrieved and fertilized in the laboratory, there may be more embryos created than can reasonably be transferred to the woman’s uterus. When these “extra” embryos are of sufficient quality, they may be cryopreserved (frozen) so they may be transferred at some future date. Embryo cryopreservation, which is possible in approximately 60% of IVF cycles at IRMS, provides the opportunity to have an additional embryo transfer without the inconvenience and expense of an additional IVF cycle.