There are a number of reasons to consider sperm cryopreservation (freezing). Some couples find it more convenient to have a sample of the man’s sperm frozen in advance of the ART treatment, particularly if they anticipate collection difficulties. Sperm freezing is also useful for men whose occupations either require them to travel extensively, or exposes them to an environment that potentially affects sperm viability.

Men about to undergo a vasectomy or a medical treatment that is expected to make them sterile (such as some forms of cancer treatment), can freeze their sperm before starting treatment, with the aim of using it to achieve a pregnancy with their partner in the future.

Sperm Cryopreservation FAQ

Can PCRM freeze sperm for donation to someone who isn’t the man’s partner?

No. PCRM is not a licensed donor sperm bank, and as such can only freeze sperm from men who intend to use it to achieve pregnancies in the future with their partner.

Does freezing affect the sperm?

Some sperm in each sample will not survive the freeze/thaw process, but there is no evidence that freezing affects the genetic material of those that survive. Different samples respond differently to cryopreservation and it is not possible to predict this from the fresh sample. The PCRM laboratory performs a "test thaw" on a small portion of each sample that is frozen to give your doctor an indication of how the sperm react to freezing. The length of time a sample is stored does not affect its chance of survival, so your doctor can use this information in the future, when developing your ART treatment plan.

How are the frozen sperm stored?

The semen sample is diluted carefully with a cryoprotectant solution designed to protect the sperm during freezing. Once diluted, the sample is divided up and put into straws for freezing. At PCRM, we use CBS High Security Straws, a cryopreservation system that minimizes any risk of sample cross-contamination in the storage tank. These straws have a separate compartment so that the sample’s identification and sample can be sealed inside the straw. The straws are heat sealed at both ends, and then cooled in controlled-rate freezers. Once the samples have cooled to -150°C, they are transferred into a storage compartment in a liquid nitrogen storage tank, where they are stored at -196°C until needed.

How secure is my frozen sperm sample?

To access the PCRM storage facility, one would need to pass through 4 locked doors, that are only accessible to specific PCRM medical and laboratory staff. Our facility also has an independent security system and a security guard for the building 24 hours a day. The storage tanks are filled with liquid nitrogen, and the levels are checked and recorded weekly. The holding time for these tanks is several weeks, meaning that if for some reason it was not possible to top up the liquid nitrogen, the samples could still stay frozen. Also, because we use liquid nitrogen, and not electricity, samples will remain safely frozen during power outages.