This technology is very useful for some patients where they will either be unavailable or absent at the time when their partner needs treatment, or they are concerned they may have issues with sperm production on the day of the egg collection procedure when his sperm is collected. In more complex cases like surgical sperm recovery where surgery has been used to obtain sperm, freezing of the sperm allows the patients to proceed with ICSI treatment knowing they will have sperm to utilise on the egg collection day.