Sperm freezing

A process that enables the scientists to store sperm for future use in fertility treatment.

Sperm freezing is a method of fertility preservation that is designed to allow patients to have a family, or to help someone else to have a family, at a later date. The process will involve a patient producing a semen sample, this sample being frozen and stored, and then having the sample retrieved and thawed whenever it is ready to be used in a fertility treatment procedure.

For male patients, or for non-binary or transgender patients who were born male, sperm freezing is the most successful method of fertility preservation. This may be so that they are able to have a family of their own one day, but often it is carried out to donate their sperm to someone else’s fertility treatment. 

  • You may wish to consider freezing your sperm to preserve your fertility if:
  • You have a medical condition, or are facing treatment for a medical condition, which may affect your fertility
  • You have a low sperm count or the quality of your sperm has been found to be deteriorating
  • You have difficulty producing a sperm sample on the day of a fertility treatment
  • You are about to have a vasectomy and want sperm available in case you change your mind about having (more) children
  • You are currently male but transitioning to female and wish to preserve your ability to have children before you start hormone therapy or have reconstructive surgery
  • You are at risk of injury or death (for example, if you are a member of the Armed Forces and being deployed)

There is a particular process that must be carried out before your sperm can be frozen. First, it must be tested and screened for any infectious diseases, such as HIV or Hepatitis. Under the regulations set out by the HFEA, the results should not affect your ability to freeze your sperm, though it must be noted that not every unit will be able to store virology-positive samples. As such, many will not offer this as a service.

After these tests have been carried out, you will need to give written, informed consent that specifies:

  • How long you want your sperm to be stored (the standard length of time is 10 years)
  • Whether the sperm are only to be used for your treatment, can be donated to someone else’s, or can be used for research or training
  • What should happen to your sperm in the event of your death, or in the event that you are unable to make decisions for yourself
  • Any other conditions you may have regarding the use of your sperm

Once these steps are complete, you should be invited to your chosen clinic to produce your sample. This will be a fresh sample produced via masturbation, if you are able to do this. Any sample you provide will then be mixed with a cryoprotectant fluid to keep the sperm from becoming damaged during freezing.

Before the freezing itself, the sperm will normally be divided between a number of containers known as “straws”. This ensures that not all of the sperm is thawed and used at once, and can therefore be used in multiple treatments. All the samples will then be slowly cooled and plunged into liquid nitrogen.

When the time comes for the sperm to be used, it will be thawed and utilised as part of a fertility treatment process. This will normally be in-vitro fertilisation (IVF) or intrauterine insemination (IUI). If the sperm is not of optimum quality, then intracytoplasmic sperm injection (ICSI) may also be considered.

Frozen sperm will be used in fertility treatments in the exact same way as fresh sperm would be. Treatments with frozen sperm have been found to be just as successful, and there are currently no known risks to patients or children born from using a frozen sample.