Azoospermia – Can a Man Actually Have Zero Sperm Count?

By BSc, MSc (embryologist), BSc, MSc (embryologist) and BA, MA (fertility counselor).
Last Update: 11/19/2018

Azoospermia, commonly referred to as zero sperm count, is described as the absence of measurable sperm in the ejaculate (semen). Depending on the cause, it can be classified into two types: secretory or non-obstructive azoospermia, and obstructive azoospermia.

The chances of achieving pregnancy with azoospermia are dependent on the type, too. If it is obstructive azoospermia, sperm can be collected with a testicular biopsy to be used for ICSI. However, in cases of secretory azoospermia, retrieving sperm is more complicated, and the man might need to use donor sperm to have a baby.

Definition & diagnosis

A semen analysis or seminogram is the most common test to check fertility in males. To perform this test, a sperm sample is collected and then evaluated in the laboratory in order to check the sperm count and motility.

When the semen analysis report is available, sperm count is compared with the diagnostic reference values provided by the World Health Organization (WHO):

No sperm in the semen.
Less than 100,000 sperm per milliliter of semen.
Less than 15 M/ml.
All sperm parameters are normal.

Considering this classification, azoospermia can be defined as a sperm disorder in which the male lacks sperm cells in the ejaculate. It is estimated that, out of all male infertility problems, azoospermia is present in between 3 and 10 percent of the cases.

Azoospermia is a medical condition that has no noticeable symptoms. This is the reason why, for its diagnosis, it is necessary to perform a semen analysis.

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Determining FSH hormone levels might be useful as well. This hormone is produced by the brain and is responsible for spermatogenesis (production of spermatozoa) in the testes. If FSH levels are too high, it translates into a decreased level or the absence of stem cells in the sperm sample. A testosterone and fructose test is advisable, too.


The fact that the man has no sperm in the semen can be due to two main causes:

Secretory or non-obstructive azoospermia
The testes are incapable of producing sperm.
Obstructive azoospermia
Sperm are produced, but the cannot be expelled with the ejaculate due to an obstruction in the ejaculatory ducts.

Carrying out a testicular biopsy is necessary in order to determine the type of azoospermia. It consists of taking a tissue sample from the each testicle in order to check if it produces sperm (obstructive azoospermia) or not (secreting azoospermia).

Getting your hormones tested might also help to determine the type of azoospermia. If the levels of hormones that play a role in spermatogenesis are altered, the diagnosis will be secretory azoospermia. However, this method is not so accurate as testicular biopsy to determine whether a few sperms could be retrieved and used in a fertility treatment.

Secretory or non-obstructive azoospermia

Secreting or non-obstructive azoospermia is the most severe, frequent type of azoospermia, being present in 70% of cases. It can be congenital (condition existing at birth) or acquired (due to an illness or treatment with toxic medicines). These are the most common causes:

  • Undescended testicles
  • Exposure to toxic substances: drugs, radiotherapy, and chemotherapy.
  • Genetic disorders
  • Hormonal imbalances
  • Testicular diseases: mumps, trauma, inflammations, and severe varicocele.

Sperm retrieval when suffering from non-obstructive azoospermia is complicated, since no sperm is produced. The good news is, pregnancy is possible. In some cases of male infertility, minor concentrations of sperm have been found in the testes. Thus, multiple and small testicular biopsies are performed in order to find sperm. If any sperm is found, it will be frozen and used later in ICSI.

Depending on the cause of azoospermia, it is also possible to recover fertility by means of hormonal treatment, thereby allowing the patient to be able to conceive.

In the most severe cases of secretory azoospermia, the man may have no alternative but to use donor sperm to have a baby.

Obstructive azoospermia

Obstructive azoospermia is due to a problem in the sperm ducts which transport the sperm from the testicles to the urethra, in which the ejaculate occurs. The most common causes of this type of azoospermia are:

  • Absence of vasa deferentia, owing to either congenital reasons or after a surgical procedure.
  • Inflammations or trauma in the testes, epididymis, vasa deferentia, or prostate.

However, obtaining sperm is easier with this sperm disorder. In certain cases, this type of azoospermia can be treated and even reversed. The obstruction can be removed or the separated ducts can be reunited by means of different microsurgery techniques, which will allow sperm to be found in the semen.

If this were not possible, sperm would be collected from the testicles by means of testicular biopsy and used in ICSI. Usually, a single biopsy is enough, since spermatogenesis occurs with normality in males with obstructive azoospermia.

Azoospermia and varicocele

The relationship between azoospermia and varicocele is rather common, since 5% of varicocele cases end up developing azoospermia. However, this only occurs among the most severe cases of varicocele.

Want to learn more about your options of conceiving with varicocele? Read more: Achieving Pregnancy with Varicocele.

Varicocele is defined as an abnormal enlargement of the veins found in the human male spermatic cord, determined by an enlargement of the spermatic veins. It affects spermatogenesis directly.

Patients with secretory azoospermia who undergo surgery for correcting varicocele usually recover 50% of their testicular tissue. In addition, sperm motility after ejaculation is recovered in 55% of cases.

FAQs from users

What is the difference between cryptozoospermia and azoospermia?

By Zaira Salvador BSc, MSc (embryologist).

It is not unusual that, when seeing that the sperm count is zero, sperm samples are diagnosed with azoospermia instead of cryptozoospermia.

The difference between azoospermia and cryptozoospermia is decisive, since a wrong diagnosis may lead to a testicular biopsy or epididymal sperm aspiration to retrieve sperm when there are viable sperms in the ejaculate, but only a few. The difficulty here is being able to find this few sperm in order not to be mistaken.

To avoid errors and provide the patient with the appropriate diagnosis of cryptozoospermia, the most advisable is to repeat the semen analysis. This time, the semen sample should be examined after having gone through a centrifugation process.

Is azoospermia the same as aspermia?

By Rebeca Reus BSc, MSc (embryologist).

No, they are not. Azoospermia equals having no sperm in the semen, but the man does not have issues with ejaculating. Conversely, aspermia refers to absence of ejaculation ability. In other words, aspermia does not affect sperm.

Is pregnancy possible with IUI in cases of azoospermia?

By Rebeca Reus BSc, MSc (embryologist).

No, it is not. The main requirement for IUI to be possible is to have a normal sperm count. Unfortunately, azoospermia patients have no sperm in the ejaculate.

Can a man with zero sperm count get a woman pregnant?

By Rebeca Reus BSc, MSc (embryologist).

The only possible way for males with secretory azoospermia to cause a pregnancy is by means of a hormonal treatment, as long as it leads to the recovery of spermatogenesis. However, this is unlikely in many cases, so the answer to this questions is that it depends on the cause of azoospermia.

If my sperm count is zero but I have obtained few sperms with a testicular biopsy, what are my chances of success with ICSI?

By Zaira Salvador BSc, MSc (embryologist).

As explained earlier, a single sperm per egg retrieved is enough, so there is no need for it to have an excellent quality. This is the reason why obtaining viable embryos is possible by removing the sperms directly from the testis.

Suggested for you

If you wish to learn more about all the types of sperm disorders that may occur in males, my advice is that you visit this comprehensive guide to all of them: Sperm Disorders that Cause Male Infertility – Causes & Treatment.

Throughout this post, we have mentioned that IVF with ICSI is the only treatment option for males with secretory azoospermia wishing to have children. Want to get more info on this technique? Read: What Is ICSI Technique? – Process, Success Rates & Cost.

Our editors have made great efforts to create this content for you. By sharing this post, you are helping us to keep ourselves motivated to work even harder.


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Cooper TG, Noonan E, von Eckardstein S, et al. World Health Organization reference values for human semen characteristics. Hum Reprod Update 2010;16:231-45.

Fogle RH, Steiner AZ, Marshall FE, et al. Etiology of azoospermia in a large nonreferral inner-city population. Fertil Steril 2006;86:197-9.

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Male infertility best practice policy committee of the American Urological Association (AUA). The optimal evaluation of the infertile male. AUA Best Practice Statement. Revised, 2010.

Matsumiya K, Namiki M, Takahara S, et al. Clinical study of azoospermia. Int J Androl 1994;17:140-2.

WHO Manual for standardized investigation and diagnosis and management of the infertile male. Cambridge: Cambridge University Press, 2000.

FAQs from users: 'What is the difference between cryptozoospermia and azoospermia?', 'Is azoospermia the same as aspermia?', 'Is pregnancy possible with IUI in cases of azoospermia?', 'Can a man with zero sperm count get a woman pregnant?' and 'If my sperm count is zero but I have obtained few sperms with a testicular biopsy, what are my chances of success with ICSI?'.

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Authors and contributors

 Rebeca Reus
Rebeca Reus
BSc, MSc
Degree in Human Biology (Biochemistry) from the Pompeu Fabra University (UPF). Official Master's Degree in Clinical Analysis Laboratory from the UPF and Master’s Degree about the Theoretical Basis and Laboratory Procedures in Assisted Reproduction from the University of Valencia (UV). More information about Rebeca Reus
 Zaira Salvador
Zaira Salvador
BSc, MSc
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
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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