Patients concerned about their future fertility usually use fertility preservation. Fertility preservation is the cryopreservation (freezing) of human reproductive tissue to be used later for IVF therapies or intra uterine insemination (IUI). With the use of liquid nitrogen, human tissues such as semen, eggs, and embryos are frozen at temperatures exceeding 350 degrees below freezing and stored in specially designed tanks. When the patient is ready to begin a family, the tissues will be shipped to CFI, thawed, and used in a procedure to impregnate the woman. Regardless of the causes of infertility, cryopreservation and cryostorage are advances in the medical field that allow patients another attempt at having a family.