Post Vasectomy Semen Analysis – How Many Tests to Confirm Sterility?

By (embryologist) and (fertility counselor).
Last Update: 03/06/2018

When a man decides to undergo vasectomy in order to have unprotected intercourse without risk of conceiving, one should make sure that it has been 100% successful, that is, there is no risk of unintended pregnancy.

For this reason, doing several vasectomy rechecks is necessary during a few months post vasectomy in order to confirm whether the sperm count is zero. In other words, if the treatment has been successful.

Advantages of vasectomy

A vasectomy is a type of permanent sterilization for males that involves the resection and ligation of the vasa deferentia of the male reproductive system. As a result, the man is expected to have obstructive azoospermia, that is, zero sperm count due to a blockage in the vasa deferentia.

This birth control method is permanent in almost all cases. For this reason, men who regret having had a vasectomy and wish to conceive in the future, will have no alternative but to undergo a vasectomy reversal.

On the other hand, the following are the potential advantages of vasectomy:

  • A vasectomy is a painless procedure that is very convenient for those males who don't want more children
  • It doesn't lead to unpleasant intercourse, inhibit the capacity for the man to ejaculate, or lower sex drive
  • The man will continue to have orgasms as always
  • Unprotected intercourse can be resumen about one week after the surgical procedure, provided that everything goes as expected

It should be noted that this technique does not protect against STDs (Sexually Transmitted Diseases), a major disadvantage if compared to the condom.

Post vasectomy sperm tests

A semen analysis, also known as seminogram or semenogram, is a diagnostic test used for male fertility testing. It allows the specialist to evaluate the different sperm parameters, including sperm concentration, sperm motility, and sperm morphology.

This is the reason why a semen analysis is so useful when it comes to evaluate under the microscope whether there is presence of spermatozoa or not after a vasectomy.

The effectiveness of vasectomy is 99%, but the effects are not immediate. The male has to ejaculate a few times after the procedure in order to release all the sperms that are still present on the seminal ducts, which could cause a pregnancy.

So, in order to prevent an unwanted pregnancy after the first months, couples are strongly advised to continue using other birth control methods.

Prior to giving sperm clearance, a series of post vasectomy sperm tests are required until no sperms are found on the semen sample. This would mean that the treatment has been successful.

The first semen analysis can be done 3 months after vasectomy, when the man is expected to having ejaculated an average of 20 times.

About 80 percent of men with a vasectomy will have no sperms in the 3-month recheck. In these cases, sperm clearance is given after this sperm test. If the sperm test was positive after vasectomy, further rechecks would be necessary until the sperm count is zero.

In spite of this, some specialists recommend these men to undergo annual rechecks in order to make sure that recanalization of the vasa deferentia doesn't occur, which would lead to vasectomy failure.

Sperm clearance after vasectomy

To determine if the results of a vasectomy have been successful or not, clearance can only be given based on the absence of motile sperm. Particularly, the sperm count should be below 100,000 motile sperm per sample or ideally zero.

However, sometimes it takes longer than expected to reach zero sperm count. In this case, the semen analysis would be repeated 6 months after the procedure. If the sample still contains sperms, the vasectomy procedure should be done again.

Giving sperm clearance to these patients is not possible if motile spermatozoa are still present on the ejaculate, as this would mean that pregnancy is still possible. Whenever motile sperm are present, the man could get a woman pregnant.

To determine if a vasectomy has been successful, azoospermia must be diagnosed after one or two post vasectomy sperm tests.

FAQs from users

Do you shoot blanks after a vasectomy?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

No, this is a common misconception about vasectomies. As a matter of fact, there's no noticeable change in the volume of sperm the man ejaculates. Neither do the smell and the color change. It should be kept in mind that less than 3 percent of the sperm volume is made up of sperm.

How long does it take for a man to become sterile after a vasectomy?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

Actually, it takes some time for sperm to disappear fully from the vasa deferentia. It is estimated that, by 10 weeks, 85% of men will have no sperm in the ejaculate.

Why two sperm tests after vasectomy?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

It is not required in all cases. If the sperm count is zero after 3 months, no further rechecks would be necessary. However, for some men it takes longer and need a second recheck after 6 months.

Suggested for you

Men who want to have children after vasectomy have no choice but to consider undergoing vasectomy reversal or IVF with Testicular sperm extraction (TESE). Check out this for information: Can You Get Pregnant After a Vasectomy? – Your Realistic Possibility.

The semen analysis is the most important test to evaluate male fertility. Get more info by clicking the following link: What Is a Semen Analysis Report? – Purpose, Preparation & Cost.

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 Zaira Salvador
Zaira Salvador
B.Sc., M.Sc.
Bachelor's Degree in Biotechnology from the Technical University of Valencia (UPV). Biotechnology Degree from the National University of Ireland en Galway (NUIG) and embryologist specializing in Assisted Reproduction, with a Master's Degree in Biotechnology of Human Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI) More information about Zaira Salvador
License: 3185-CV
Adapted into english by:
 Sandra Fernández
Sandra Fernández
B.A., M.A.
Fertility Counselor
Bachelor of Arts in Translation and Interpreting (English, Spanish, Catalan, German) from the University of Valencia (UV) and Heriot-Watt University, Riccarton Campus (Edinburgh, UK). Postgraduate Course in Legal Translation from the University of Valencia. Specialist in Medical Translation, with several years of experience in the field of Assisted Reproduction. More information about Sandra Fernández

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