What Is Asthenozoospermia? – Causes & Treatment

By BSc, MSc (embryologist), BSc, MSc (embryologist), BSc, MSc (embryologist) and BA, MA (fertility counselor).
Last Update: 12/05/2018

Asthenozoospermia, also known as asthenospermia, is an alteration that affects sperm motility. It is commonly known as slow moving sperm or lazy sperm.

Throughout this article, we will explain the causes of poor sperm motility, as well as the methods used to detect it, and the best treatment options.

Diagnosis

seminogram is the diagnostic test used for its detection. During sperm analysis, a drop of semen is introduced into the sperm-counting chamber (Makler or Neubauer chamber) under the microscope, and 100 spermatozoids are counted.  

The percentage of these that exhibit progressive motility,  the percentage of non-progressive motile sperm (those who have movement but do not move) and finally the percentage of immotile sperm are determined.

According to criteria established by the WHO, a man does not suffer from asthenozoospermia, that is to say, their sperm has normal motility when it presents:

  • Values equal to or above 40% of motile sperm (progressive and non-progressive).
  • Values above 32% of sperm with progressive motility, that is to say, capable of moving forward.

Lower levels are considered abnormal or precursors of asthenozoospermia.

Repeated semen analyses

According to embryologist Laura Mifsud, it is crucial to repeat the semen analysis before rendering a definitive diagnosis of asthenozoospermia to a patient. Diagnosing asthenozoospermia or any other sperm diagnosis with a single sperm analysis is a mistake, since it might be due to a external or environmental factor, or a temporary circumstance of the patient.

For this reason, repeating the sperm test is essential to confirm the diagnosis. Moreover, the time period between semen analyses should be a reasonable one in order to make sure the external factor influencing it has disappeared.

Types or grades of asthenozoospermia

Depending on the specific percent of immotile sperm that are present on the sample examined, we can distinguish several types of asthenozoospermia.

As one shall see below, the different grades of asthenozoospermia are not clearly defined. The final diagnosis can be more or less severe based on the type and speed of motion, as well as on the number of immotile sperm.

Broadly speaking, there exist two grades of severity:

Mild-to-moderate

This level is diagnosed when the percent of immotile sperm, or sperm with poor motility, ranges between 60 to 75%.

As in the previous case, the type of motion should be classified. The rationale for this is as follows: if only a few are able to swim but they more progressively and forward, it can be qualified as mild asthenozoospermia.

Severe

Severe oligospermia is diagnosed when the percent of sperm with poor or absent motility is very high.

Although there exists no specific value, we could determine that it is a severe case of asthenozoospermia if the percent of immotile sperm is close to 75-80% or even higher.

One should pay special attention not only to total motility, but also the type of motion. If the number of sperm with progressive, fast motility is too low, it would be qualified as severe asthenozoospermia as well.

Causes

The causes of asthenozoospermia are not precisely defined.  However, it is known that sperm motility may be influenced by the following factors:

  • Presence of antisperm antibodies
  • Excessive consumption of alcohol or other drugs (snuff, marijuana, etc)
  • Advanced age: there’s a significant decrease in mobility after 45 years
  • Fever
  • Exposure to toxic agents (fertilizers, chemical solvents)
  • Infections that affect the sperm
  • Poor nutrition
  • Prolonged exposure to heat
  • Testicular problems.
  • Teratozoospermia, which refers to alterations in the form of the sperm
  • Cancer treatments such as chemotherapy and radiotherapy
  • Varicocele

The presence of other sperm disorders such as teratozoospermia or oligospermia can cause asthenozoospermia. All in all, they all refer to poor sperm quality.

The term teratozoospermia refers to abnormalities that affect sperm morphology. On the other hand, oligospermia is used to refer to the presence of a low sperm count in the semen.

Treatment for “lazy sperm”

As for possible treatment options, there exist two possible ways one can improve sperm morphology or even restore normal morphology:

Natural treatment
It is important to lead a healthy lifestyle, quitting toxic habits that may damage the overall quality of sperm, including sperm quality. This can help restore fertility in some cases of mild or moderate asthenozoospermia.
Pharmacological treatment
There exist some medications that could be used to boost sperm quality and reduce sperm morphology issues. Nonetheless, this only works in mild cases of male infertility due to a sperm disorder.

In cases of severe asthenozoospermia, restoring fertility with any of these treatment options is complicated. The only option left to become a father would be Assisted Reproductive Technology (ART).

Asthenozoospermia & infertility

Asthenozoospermia is a cause of male infertility. The ultimate goal of sperm cells is to fertilize the egg and create a new being. In order to do this, they have to overcome several obstacles until they can reach the Fallopian tubes, where the oocyte is waiting. Since sperm motility is affected with asthenozoospermia, achieving this goal is complicated. For this reason, Intrauterine Insemination (IUI) is not recommended in these cases.

Throughout the female reproductive tract, sperm encounter multiple barriers: only the most agile and quickest will overcome all of them, reaching the final goal, that is to say, meeting the egg cell. For this reason, progressive movement and speed motion are key aspects to keep in mind when it comes to achieving a natural pregnancy.

When sperm are unable to move forward, or they do so but inadequately, getting pregnant naturally becomes very hard. In these cases, ART is the only option left to become parents.

Options to achieve pregnancy

When a man is asthenozoospermic and therefore is unable to get his wife or partner pregnant, the most recommendable treatment option is In Vitro Fertilization (IVF), either conventional or using ICSI (Intracytoplasmic Sperm Injection). Artificial insemination is contraindicated in cases of poor sperm motility. In short, these are the potential assisted reproduction treatment options available:

Conventional IVF
In cases of mild asthenozoospermia, this technique is possible, which is the simplest, most physiological version of IVF. With this technique, the sperm meets the egg by itself.
ICSI
In the most severe cases of asthenozoospermia, this is the first option. Contrary to the conventional version, in this case it is the embryologist who injects the sperm into the egg, so motility is not required.
Sperm donation
If pregnancy is not achieved with any of the two techniques already mentioned, using donor sperm would be the only option to father a child.

If you need to undergo IVF to become a mother, we recommend that you generate your Fertility Report now. In 3 simple steps, it will show you a list of clinics that fit your preferences and meet our strict quality criteria. Moreover, you will receive a report via email with useful tips to visit a fertility clinic for the first time.

FAQs from users

Can I conceive naturally with asthenozoospermia?

By Andrea Rodrigo BSc, MSc (embryologist).

There are still chances of achieving a natural pregnancy with asthenozoospermia if it is a mild-to-moderate case. However, if sperm motility is severely affected, the only option to become parents would be using a fertility treatment like IVF with ICSI.

What are the symptoms of asthenozoospermia?

By Andrea Rodrigo BSc, MSc (embryologist).

Unfortunately, there are no symptoms associated with asthenozoospermia. The only possible way for a patient to suspect that he has this sperm disorder is by doing a semen analysis.

Are teratozoospermia and asthenozoospermia caused by the same factors?

By Zaira Salvador BSc, MSc (embryologist).

In most of the cases, asthenozoospermia and teratozoospermia have the same causes. Both sperm parameters appear altered in the semen analysis, which is known as asthenoteratozoospermia. Nonetheless, they do not go hand in hand in all cases.

Suggested for you

Throughout this post, we have explained all about asthenozoospermia, which is a sperm disorder that affects sperm motility. But what do you know about this sperm parameter? Do you want to learn more about the way sperm swim? Find it out: How Is Sperm Motility Examined?

Also, several references to the semen analysis test have been made through this article, as it is the only test that allows us to diagnose not only asthenozoospermia, but also other sperm disorders. To learn more about this diagnostic test, read: What Is a Semen Analysis Report? – Purpose, Preparation & Cost.

Last but not least, if you are interested or need to undergo ICSI, the fertility treatment typically used to achieve pregnancy with asthenozoospermia, click here: 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.

References

Aitken RJ, Buckingham DW, Brindle, J, Gomez E, Baker HWG, Irvine DS (1995): Analysis of sperm movement in relation to the oxidative stress created by leukocytes in washed sperm preparations and seminal plasma. Hum Reprod 10:2061–2070.

Blanco AM (1992): El laboratorio en el estudio del factor masculino en infertilidad. In: Guitelman A, Aszpiz SM (Eds). Exploracion Funcional Endocrina. Buenos Aires: Ed. Akadia, 1992.

Bruno Dahlberg (1990) Asthenozoospermia/Teratozoospermia and Infertility, Archives of Andrology, 25:1, 85-87.

Dahlberg B (1988): Sperm motility in fertile men and males in infertile units: In vitro test. Arch Androl 20:31-34.

Reproducción Asistida ORG. Video: Astenozoospermia (Asthenozoospermia), by Laura Mifsud Elena, BSc, MSc, Jul 8, 2015. [See original video in Spanish].

S. M. Curi, J. I. Ariagno, P. H. Chenlo, G. R. Mendeluk, M. N. Pugliese, L. M. Sardi Segovia, H. E. H. Repetto & A. M. Blanco (2003) Asthenozoospermia: analysis of a large population, Archives Of Andrology, 49:5, 343-349.

World Health Organization (1992): WHO Laboratory Manual for the Examination of Human Semen and Sperm–Cervical Mucus Interaction, ed 3. Cambridge,UK: Cambridge University Press.

FAQs from users: 'Can I conceive naturally with asthenozoospermia?', 'What are the symptoms of asthenozoospermia?' and 'Are teratozoospermia and asthenozoospermia caused by the same factors?'.

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Authors and contributors

 Andrea Rodrigo
Andrea Rodrigo
BSc, MSc
Embryologist
Bachelor's Degree in Biotechnology from the Polytechnic University of Valencia. Master's Degree in Biotechnology of Human Assisted Reproduction from the University of Valencia along with the Valencian Infertility Institute (IVI). Postgraduate course in Medical Genetics. More information about Andrea Rodrigo
 Laura Mifsud Elena
Laura Mifsud Elena
BSc, MSc
Embryologist
Bachelor's Degree in Biology from the University of Valencia (UV). Master's Degree in Biomedical Research from the University of Valencia, and another Master's Degree in Medicine and Reproductive Genetics from the Miguel Hernández University of Elche. Large experience working as an embryologist and head of laboratory at the Quirónsalud Hospital of Valencia, Spain. More information about Laura Mifsud Elena
 Zaira Salvador
Zaira Salvador
BSc, MSc
Embryologist
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
BA, MA
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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