Cryopreservation of Spermatozoa

Abstract

Cryopreservation is a technique that keeps the cells and tissues in a vital state, using cryogenic temperatures (−196 °C). Despite the first experiments of sperm preservation with snow dating back to the eighteenth century, it was only the discovery of the protective role of glycerol against freezing damage in the twentieth century and the use of liquid nitrogen that started the era of modern cryobiology. The use of cryoprotectants and adequate cryopreservation methods (rapid or slow freezing procedures) allow to prevent freezing damage and maintain the cells in a state of “suspended animation” which will preserve for a long time. Sperm Bank is a medical facility characterized by two purposes: to preserve the patient’s fertility and to access to assisted reproduction techniques (ART). There are many indications (neoplasms, autoimmune diseases, urological pathologies) but, as a general rule, semen or testicular tissue cryopreservation must always be executed before any therapy, which may interfere with either spermatogenesis and genome integrity or ejaculation mechanisms. Also, it is possible to cryopreserve a patient’s semen to facilitate access to ART. The activities of a Sperm Bank are strictly regulated by the current EU legislation. This involves quality standards, structural and personnel requirements, archive, traceability, storage, and distribution of human tissues and cells. These rules consist in the adoption by the various Member States of Directive 2004/23/EC and following (2006/17/EC and 2006/86/EC) issued by the European Parliament.