The process of freezing one or more embryos to save them for future use. Embryo freezing involves in vitro fertilization, a procedure in which eggs are removed from a woman’s ovary and combined with sperm in the laboratory to form embryos. … Also called embryo banking and embryo cryopreservation/ Semen cryopreservation (commonly called sperm banking or sperm freezing) is a procedure to preserve sperm cells. Semen can be used successfully indefinitely after cryopreservation. For human sperm, the longest reported successful storage is 24 years.