After undergoing a vasectomy, semen testing is typically performed to confirm the success of the procedure and ensure that the sperm count is low enough to stop using other forms of contraception. Let’s explore the why, how, and when of semen testing after a vasectomy.

Why is semen testing necessary after a vasectomy?

Semen testing is necessary to confirm that the vasectomy procedure has effectively blocked the vas deferens, the tubes that carry sperm from the testicles to the urethra. A low count, or absence, of sperm in the ejaculate confirms that the man is no longer able to get a woman pregnant.  Until this testing is successful, it is necessary to use other forms of contraception.  

How is semen testing performed?

Testing is looking for either an absence of sperm or a very low count of sperm.  A low count of sperm can be used instead of complete absence, because it is known that under a certain level, studies have shown that it is impossible to impregnate a woman.  

At Go Vasectomy we recommend a home test.  It is reliable (see this study) and super convenient.   Home tests  look for the presence of a protein that is associated only with sperm.  SpermCheck Vasectomy is a popular test of this type.  It is a home test, similar to a home pregnancy test.  The man makes a semen sample, usually by masturbation, and applies it to a card using specific instructions.  The card displays a “low count” or “high count” result.  Men often ask if “low count” is good enough for this important protection.  When there is a “low count” result, it means that the number of sperm is below the level at which the American Urologic Association says it is impossible to get a woman pregnant.  The tests come as a set of two.  We recommend 2 days of abstinence before doing each test.  You should get two “low count” results separated by at least 2 days at which time it is OK to stop other forms of birth control. 

If you receive a “high count” result at 2 months, then it is recommended you purchase another home test kit and repeat it around 3 months after the vasectomy.  If you still have a “high count” result at 3 months, then a sample must be checked at a lab or doctor’s office. Your vasectomy may not have worked, or you may have a “false positive” test in which the test is indicating there is sperm present, when in fact, there is not sperm present.

The second  method for testing is to look at a semen sample under a microscope. The patient brings a sample to a doctor’s office or lab. The presence, absence or count of sperm is assessed under the microscope. There are mail-in labs that provide an easy way of having this done.  One is https://malefromhome.com/ and another is https://www.pvsa.org/.

In either case, a low count or absence of sperm indicates a successful vasectomy.

When should semen testing be conducted after a vasectomy?

We recommend doing the initial testing around 8 weeks after vasectomy.  This waiting period allows for any residual sperm to be cleared from the reproductive system. Doing the test earlier increases the risk of having residual sperm still in the system, and needing to repeat the test.  Doing the test later means that the benefits of the vasectomy aren’t enjoyed as soon as possible. 

The initial semen test is often performed about 8 to 16 weeks (2 to 4 months) after the vasectomy. This time frame ensures that any remaining sperm have been flushed out or absorbed by the body. Sperm are hardy and can remain living in the vas deferens or prostate for several months.

Many men ask if frequent ejaculation will clear sperm from the vas deferens, rather than waiting the 8-16 weeks.  Many doctors recommend a minimum of 15-20 ejaculations prior to testing. This will help, and it will ensure a successful test, but testing before 8 weeks is not generally recommended. 

It is important to note that until the semen analysis confirms the absence of sperm, alternative contraception methods should be used to avoid unwanted pregnancies. It is not safe to rely solely on the vasectomy for contraception until the semen testing  has confirmed a count under a certain threshold. 

In summary, semen testing after a vasectomy is crucial to confirm the success of the procedure and determine when it is safe to rely on the vasectomy as a form of contraception. It is easiest to do the home test, and it has proven to be very reliable.