Cryopreservation is a freezing technique by which sperm can be stored and used for future fertility. The procedure that can be done using the thawed sperm will depend on how much sperm was originally frozen, and how well the sperm responded to the freezing. Whole ejaculates that were frozen and thaw well may be used for IUI (In Utero Insemination), while other specimens that are not as good may need to be used with the IVF (In Vitro Fertilization) process. In addition to the ejaculated sperm, testicular tissue can be frozen for future use as well. Frozen testicular specimens and epididymal aspirates do not produce the sperm quantities necessary for anything other than the IVF process.

The better the quality of the sperm sample frozen, the more likely it will survive the thawing process. As a rule of thumb, half of the sperm that was good prior to freezing will survive the thaw. There are instances when sperm that appears viable prior to freezing will not be viable after the thaw process. We typically freeze smaller quantities of sperm, called test vials, to thaw before sperm is needed so that we are not caught off guard when we do need the sperm. In addition, in circumstances where sperm retrieval is performed, the sperm that is extracted may either not be good enough to freeze, or may be so abnormally shaped that it is not worth freezing.

If you have any questions about these issues, please don’t hesitate to ask.