Post-vasectomy semen analysis: Why is it important?

Procedure | Results | Summary

The post-vasectomy sperm count is a crucial part of the vasectomy process. A semen analysis is the only way to be 100% sure that a man is sterile after his procedure. There are many reports of unwanted pregnancy resulting from premature sexual intercourse after a vasectomy, assuming they are sterile before they get the final confirmation. The fact is, the only way to be sure is to provide samples, which are read under a microscope.

The process can be inconvenient – even embarrassing. But the awkwardness can be reduced if you ask the right questions ahead of time.

How soon after the vasectomy can you start bringing the samples in?

The number of samples and timing of samples before you are declared sterile varies depending who you talk to, but most doctors recommend waiting several months and having 20-25 ejaculations before the first sperm test.1Griffin T, Tooher R, Nowakowski K, Lloyd M, Maddern G. How little is enough? The evidence for post-vasectomy testing. Journal of Urology. Published online July 2005:29-36. doi:10.1097/01.ju.0000161595.82642.fc Some doctors will require a second test at a later time before clearing a man for unprotected intercourse.

The number of ejaculations is an important factor for sperm clearance after a vasectomy, which means it’s possible to be cleared after a very short time once these ejaculations have flushed the man’s system clean of all sperm. Simply waiting for the sperm to be reabsorbed will take much longer than completing the required number of ejaculations.

However, most doctors still include an element of time along with an ejaculation requirement since a high percentage of men do not return for a second test.2Christensen RE, Maples DC. Postvasectomy Semen Analysis: Are Men Following Up? The Journal of the American Board of Family Medicine. Published online January 1, 2005:44-47. doi:10.3122/jabfm.18.1.44 By waiting a bit longer than may be strictly necessary, the odds are increased that an “all clear” will be provided after the first semen analysis.

The extended waiting period can also help detect early failure due to recanalization, a natural reversal process that occurs in less than 1% of vasectomies.3Trussell J. Contraceptive failure in the United States. Contraception. May 2011:397-404. doi:10.1016/j.contraception.2011.01.021

Suggested reading

How to provide the semen sample?

Masturbation is the preferred way of getting a clean sample, as there is a smaller risk of contamination. Also, the first part of the ejaculate contains most of the sperm, which might be lost when using other methods.4Post Vasectomy Semen Analysis. Cambridge IVF. https://www.cambridge-ivf.org.uk/patients/andrology-services/post-vasectomy-semen-analysis-pvsa

One technique recommended by sperm banks is to masturbate while lying on your back, having re-positioned the jar slightly to the side of your erect penis. That way, when you ejaculate, you will not have to force your penis downward to hit the pot or funnel, but just turn it slightly to the side. Sperm banks, which should know, claim using this more natural angle makes for better and more powerful ejaculations–that is, ejaculations that produce more “product’ and less spillage, which are their major concerns.

However, if you have specific preferences on how to provide the sample, ask your doctor. In some cases, the presence of lube and saliva might be allowed. There is also a way to produce the sample during intercourse by using a special condom.

Where do you need to take the samples?

It’s a good idea to ask your doctor where exactly you should bring the sample. To a lab? To a nurse’s station? Some other designated area? Think about it: No one wants to be standing around a crowded waiting room, late to work, with a jar of semen in his hand, wondering where to put it. Hopefully, the sample can be collected in the clinic and given to ancillary staff for processing.

Can I provide the test at home?

Since semen analysis is a time-critical procedure, the specimens usually need to be produced at the clinic. However, some doctors allow producing the sample at home if you are able to deliver the sample within a reasonable time. If you arrange to give at home, ask for containers to bring the samples in.

There are also home sperm tests available, which give you the opportunity to check your sperm count and get the results almost instantly at home. However, they don’t analyze sperm motility. To be 100% certain that your vasectomy has been successful, it’s best to get the test performed by a lab.

Results and getting the “all clear”

Usually, in order to be granted clearance to stop using other methods of contraception you need to provide at least one sample where no sperm is present in the ejaculate (azoospermia) or if the repeat sample contains non-motile sperm at a count of <100,000 per ml.5Semen post vasectomy check (PVS). Gloucestershire Hospitals NHS Foundation Trust. https://www.gloshospitals.nhs.uk/our-services/services-we-offer/pathology/tests-and-investigations/semen-post-vasectomy-check/

It’s also worth mentioning that sometimes, upon hearing their vasectomy has been successful, and there’s no more sperm present in their semen, some men experience a temporary depression or a negative emotion. No matter how sure you were about having a vasectomy, and no matter how long you considered it, having been told you are infertile can still be upsetting. It doesn’t happen to all men and is usually quite short-lived if it does.

Non-motile sperm

Non-motile sperm are sperm cells which do not move on their own. The presence of a few non-motile sperm after a vasectomy does not represent a vasectomy failure, and these men will generally become completely azoospermic in time. However, most doctors are unwilling to clear a man for unprotected intercourse until there are no sperm in the ejaculate.

The presence of persistent rare non-motile sperm after a vasectomy has been debated extensively by fertility specialists. The possibility of these rare non-motile sperm causing a pregnancy is approaching 0%. However, the consequences of even a minuscule percentage of men causing a pregnancy due to non-motile sperm mean that the majority of physicians won’t allow unprotected intercourse until all sperm are absent in the ejaculate.

Summary

After a vasectomy, live sperm may still be present in a man’s semen for a number of months. This means that there is still a chance of a woman becoming pregnant long after the vasectomy, even if the procedure was technically successful. Until a man has reached a lab-verified state of azoospermia (no sperm in the ejaculate), he and his partner must use alternate forms of contraception to guarantee pregnancy avoidance with sex.

References and further reading Vasectomy-Information.com has a strict sourcing policy. We rely on evidence-based medicine, peer-reviewed studies, reputable clinical journals, and medical associations. Learn more about how we ensure our content is accurate and up-to-date by reading our editorial policy.
  1. Griffin T, Tooher R, Nowakowski K, Lloyd M, Maddern G. How little is enough? The evidence for post-vasectomy testing. Journal of Urology. Published online July 2005:29-36. doi:10.1097/01.ju.0000161595.82642.fc
  2. Christensen RE, Maples DC. Postvasectomy Semen Analysis: Are Men Following Up? The Journal of the American Board of Family Medicine. Published online January 1, 2005:44-47. doi:10.3122/jabfm.18.1.44
  3. Trussell J. Contraceptive failure in the United States. Contraception. May 2011:397-404. doi:10.1016/j.contraception.2011.01.021
  4. Post Vasectomy Semen Analysis. Cambridge IVF. https://www.cambridge-ivf.org.uk/patients/andrology-services/post-vasectomy-semen-analysis-pvsa
  5. Semen post vasectomy check (PVS). Gloucestershire Hospitals NHS Foundation Trust. https://www.gloshospitals.nhs.uk/our-services/services-we-offer/pathology/tests-and-investigations/semen-post-vasectomy-check/

Medically reviewed by

Dr. Aaron Wiegmann, MD

Review date

May 27, 2021

Authored by

Vasectomy-Information.com editorial team

Last updated

June 20, 2020

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