Sperm Freezing | The Turek Clinic

Sperm Freezing

Preserve Fertility by Freezing Sperm

Name a 100-year old medical technique that is the purest form of preventative medicine, yet vastly underutilized? That’s right, it’s Sperm Freezing, also known as Sperm Banking

Reasons to Bank Sperm

Successful freezing of sperm is a tried and true technology. Here are reasons to consider banking sperm:

  • You have a medical or other condition (e.g. Diabetes), or are facing medical treatment for a condition (e.g. Cancer), that may threaten your future fertility.
  • Freezing sperm before a vasectomy to keep your childbearing options open.
  • You have a low sperm count or the quality of your sperm is deteriorating and you want to preserve your fertility.
  • You have difficulty producing a semen sample on the day of fertility treatments and need a backup source of sperm.
  • You are at risk of injury or death (e.g. You’re a member of the Armed Forces).
  • You are about to undergo a sex change operation.
  • You are getting older and would like children in the future, but are worried about the issues in offspring that occur with advanced paternal age.

For many patients, Sperm Freezing offers the opportunity to keep a precious resource tucked away as they forge ahead on life’s unpredictable path.

Things to Know About Freezing Sperm

Reasons to Bank Sperm

The first step is to select a sperm bank with which to freeze. There are several throughout the US and many female fertility programs will also do this for men. Importantly, as a whole, the industry is very tightly regulated by the Food and Drug Administration (FDA) to ensure the security, confidentiality, safety and quality of the process.

The sperm bank you choose will then require an array of blood, urine and other tests from you to ensure that the semen specimens that you freeze are free of sexually transmitted diseases and can be safely used in another person after thawing.

You will then need to decide what kind of sperm banking “account” you would like to have: short term (typically 1 year) or longer term (typically 3-5 years) sperm storage. Costs vary between centers and states, but are generally in the same ballpark.

The next decision is how many semen samples do you bank? Since there is no guarantee that the sperm that you bank will actually lead to a pregnancy, it’s best to think of this process as an insurance policy. To guide your decision, realize that there are two levels of assisted reproductive technologies available to use the sperm after it has been thawed:

  • Intrauterine Insemination (IUI). Timed to ovulation, IUI is a quick office procedure that is similar in complexity to a women’s PAP smear. At the fertile time of a women’s monthly, cycle, sperm is thawed, washed and then inseminated (or placed) within the uterus, well beyond the cervix. Normal activity is then resumed. Typically, each “normal” semen sample that is banked will allow for 2-3 IUI procedures after thawing. For each desired child, you should plan for 6 IUI procedures, which means freezing two to three ejaculates.
  • IVF or in vitro fertilization. Although requiring far fewer sperm for pregnancy success, IVF (which may include intracytoplasmic sperm injection or ICSI), is much more expensive (by 10 fold) and longer (several week) process by which women are given injectable medicine to “ovulate” as many eggs as possible, instead of the normal single egg per cycle. Just prior to “ovulation,” all of the eggs are collected from the ovary through a 30 minute procedure generally performed under sedation. Eggs and sperm are mixed in a laboratory dish and fertilized eggs, termed embryos, are grown for 3-6 days and then put back into the female uterus in a procedure similar to IUI. Assuming normal semen quality, each banked ejaculate should provide enough sperm for many IVF cycles.

Sperm Freezing Process

Ejaculates are frozen in a sperm-friendly solution, termed a cryoprotectant. Commonly, cryoprotectants contain glycerol along with sugars such as sucrose and are supplemented with either egg yolk or soy lecithin. Sperm are frozen in sterile vials or “straws” by either a controlled-rate, slow-cooling method or using a flash-freezing process known as vitrification until –196 degrees Celsius (-320 degrees F). In general, as with egg freezing, vitrification leads to better sperm survival after thawing than slow cooling.

Sperm Freezing Process
Figure 1. As sperm freezes or thaws, major changes in temperature lead to major changes in cell volume and affect the survival of sperm. While the sperm is frozen at a constant temperature, there is very little threat to its livelihood.

When needed, frozen vials of sperm are thawed at room temperature for use. Typically, all of the sperm that is frozen is recovered, but the proportion of sperm that is alive and moving after thaw is reduced by 50% compared to before freezing. Importantly, what drives sperm recoverability the most after freezing and thawing is not the time that sperm is frozen (months to years) but rapid temperature shifts during the freezing and also during the thawing process. Interestingly, sperm freezing and thawing can also affect sperm “function” by causing a mild degree of sperm DNA fragmentation, which can affect the ability of sperm to produce a pregnancy. The use of antioxidant-rich cryoprotectants and improved freezing protocols can minimize this risk, however.

Finally, it is important to remember that there is no evidence of an increase in birth defect rates or chromosomal abnormalities in children conceived from frozen sperm compared with “fresh” sperm in fertile couples.