Sperm freezing, or cryopreservation, is the process of preserving sperm cells for future use, which was introduced in the 1950s. It is applied to preserve fertile sperm cells in cases of infertility due to certain diseases and health problems.

There is no recorded time limit for the viability of cryopreserved sperm, as it appears to be less susceptible to deterioration than other cell types due to its low water content. Some studies have reported that cell damage can occur during freezing and thawing of sperm, but there is no known risk for a baby that comes from cryopreserved donor sperm. It is worth mentioning that cases of pregnancy after 20 years of cryopreservation have been documented.