Fertility 32

what is sperm freezing?

15 min read

Simon Körösi

Reviewed by: Joanna Elmes

Sperm freezing, also known as sperm cryopreservation, is the procedure of freezing one or more sperm samples by using liquid nitrogen.


Why should you freeze your sperm?


Sperm freezing is the most successful method of preserving a man’s fertility. This allows for the possibility of having children later on as well as becoming treatment for someone else. 

There are many reasons to freeze sperm. The most common reason is if you need treatment for cancer. There might namely not be any sperm left in the ejaculate after chemotherapy or radiation therapy. The same goes for the surgery of removing the testicles due to a testicular cancer, since sperm cannot thereafter be produced. 

Other reasons for sperm banking include:



Sperm quality decreases with age, especially after the age of 35. After 35, studies show that there is a significant increase in time to conception, increased risk of miscarriage and a decrease in pregnancy rate. Freezing your swimmers early can help provide assurance for having children later on.


Medical procedures or treatments


Men who choose to have a vasectomy may want the option of having children in the future. Also, medical treatment such as radiation treatment and chemotherapy that may negatively affect fertility can be a reason to freeze in sperm.




If you work with a high-risk job such as painting, herbicides or plastic production (due to chemical solvents), welding (due to intense heat and toxic gases), driving (due to vibration, heat exposure and sedentary lifestyle) or if you are in the military (risk of injury and exposure to toxins) you might consider freezing sperm to preserve your fertility.




Men who wish to get sterilized will sometimes want to freeze their sperm before sterilization, in case they later in life would want to father a biological child. 

Do I really need to freeze my sperm if I am young and healthy?


Many experts on the matter think that any person between 18 and 25 should freeze their sperm. This is because you never know what kind of environmental exposures or health conditions you might come across the years before you wish to have children. To do this kind of freeze, is sometimes referred to as “social freezing”. This is much more common amongst women, where social freezing is a well-known and socially acceptable preventative measure. 


Since it is as common with fertility issues among men and women, and sperm tends to be healthier the younger you are, we believe that you should see social sperm freezing as an optimization of your fertility chances for your future self.


How does sperm freezing work?




Before sperm freezing, there are a few preparations needed in order to make sure you and your sperms are healthy and suitable for freezing and later use. The preparations include:

Screening for sexual transmitted diseases (STIs) and other infections that may transmit to other sperm samples or partners during insemination (such as HIV and hepatitis)


Sperm analysis to ensure that your sperm is in good health.

If any of the two turn out to be deviating from what is optimal or medically recommended, your doctor or fertility clinic may recommend interventions such as treatments or lifestyle changes before freezing your sperm. 


Produce a sample


The next step is to produce a semen sample by masturbation or manual stimulation. This can either be done at a fertility clinic. You will need to give your written, informed consent to your sperm being stored.

In some cases, retrieving sperm cannot be done through masturbation, and a surgical procedure may be necessary. This may be the case in men who have undergone cancer treatment, a vasectomy or suffer from a mobility impairment. 


Important note: The specimen must go into a cup that is approved by the lab and after leaving the sample remain as close as possible to body temperature. The sample mustn’t contain any lubricant or moisturizers.




Once the lab has received the sample, they analyze the sample on several parameters to fully understand the quality of your sperm:

Semen volume


Sperm count


Sperm concentration


Sperm motility (how the sperm is moving)


Sperm morphology (if the sperm is properly shaped)

Post-thaw analysis


Quality testing is a very important part in the process of freezing and storing sperm. The post-thaw analysis involves thawing a small portion of the sample that has been freezed. After thawing, the sperm is re-analyzed for evaluation of its viability. The idea is to expose sperm to the very process that will take place in the future when you want the sperm to be used. 


It is normal for sperm motility to be decreased shortly after being thawed, and a giant study of more than 100.000 samples showed that approximately 80% of sperm will survive the thaw.


How successful is sperm freezing?


Treatment with frozen sperm is just as successful as treatment with fresh sperm.


How long can my sperm be stored after freezing?




What happens if I do not pay for storage?


If you for some reason do not pay your quarterly fee, we will contact you to remind you of payment. 


What happens when I want to use my sperm?


When you decide you wish to use your sperm, you need to contact and book an appointment with Nordic IVF where the sperm is frozen.

From thereon, they will help you through the entire process.

How is sperm analyzed?


Sperm is analyzed in several steps. First, the volume is measured, being the first parameter to analyze. The sample is then washed with sterile media, before being centrifuged (spun) to separate the sperm from other components such as seminal fluid and testicular tissue. Once this is done, the sample is ready to be scrutinized under the microscope. 


The first thing to look for, is whether or not there is sperm in the sample. If sperm is absent or low, the patient will need to undergo further testing. 

Second, the lab evaluates the sperm’s concentration, morphology (shape) and motility (movement). By doing this, they make sure that the sperm is healthy. These parameters are also needed to determine whether or not there is enough sperm to freeze.


How is sperm frozen and thawed?


Embryologists place prepared sperm into a special freezing solution in small vials. But before they do so, they need to make sure that the sperm is not damaged during the freezing process. Sperm is therefore mixed with a substance that draws water out of the sperm before freezing.   The same vials then go into storage freezers that contain liquid nitrogen. This allows for sperm to be stored indefinitely. Generally, the sample is divided into several vials, kept in multiple storage tanks. This is a safety precaution in case a freezer would fail.


When a patient later on decides to use the frozen sperm, it is carefully thawed until it reaches room temperature. Once thawed, it is yet again analyzed to make sure the quality of the sperm is high enough to result in a possible pregnancy. 

Did you know: Sperm stay frozen at a constant temperature of minus 196 degrees centigrade.


Can I freeze my sperm at home?


No, it is not possible to freeze your sperm at home. Sperm freezing needs to be done by and handled by professionals in a laboratory with proper instruments and proper quality controls. Sn™703 Legacy™Vault will result in a sperm test at a fertility clinic before freezing.


How do I freeze my sperm if I have a cancer diagnosis?


If you have a cancer diagnosis and wish to freeze and store sperm, we recommend you talk to your oncologist and your fertility clinic.