By Neus Ferrando Gilabert BSc, MSc (embryologist).
Last Update: 04/15/2014

Asthenozoospermia, also known as asthenospermia, is an alteration produced in the motility of the man’s sperm. It is colloquially known as slow moving sperm or lazy sperm.

seminogram is the diagnostic test used for its detection. During sperm analysis, a drop of semen is introduced into the sperm-counting chamber under the microscope, and 100 spermatozoids are counted.  The percentage of these that exhibit progressive motility,  the percentage of non-progressive motile sperm 8those who have movement but do not move) and finally the percentage of immobile sperm are determined.

A trained eye, able to assess this diversity of fast-moving shifting, is required since spermatozoids lose mobility as time passes.

Considered values

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

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

Lower levels indicate fertility problems.


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

  • Presence of sperm 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

Astenozoospermia as a cause of infertility

Spermatozoids ultimate goal 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.  Only one spermatozoid will have the ability and speed needed to reach the goal. For this reason, speed is so important.

Asthenozoospermia is one of the many male sterility problems. Without progressive movement the spermatozoids are not able to reach the egg and a pregnancy is not achieved.


To increase sperm velocity is important to have a healthy lifestyle, don’t’ use drugs and prevent long exposures to the heat. This can help restore fertility in some cases of mild or moderate astenozoospermia.

In cases of severe astenozoospermia, restoring fertility is complicated.

In order to have descendants, men with this alteration are advised to visit an assisted reproduction centre. Depending on the degree of asthenozoospermia and after having every factor analysed, experts may recommend the most appropriate treatment, IVF or ICSI. Injection is not advisable in cases of slow motility sperm.

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Authors and contributors

 Neus Ferrando Gilabert
BSc, MSc
Bachelor's Degree in Biology from the University of Valencia (UV). Postgraduate Course in Biotechnology of Human Assisted Reproduction from the Miguel Hernández University of Elche (UMH). Experience managing Embryology and Andrology Labs at Centro Médico Manzanera (Logroño, Spain). More information
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  1. Featured
    Debasish Roy

    Hi Doctor,

    I am a 39-year-old male having married last year 2015. I have high blood pressure (BP) and there I’m taking medicine, 5 mg amlodipine daily for the last 7 years. We are trying for a baby for the last 9 months. But no positive results. I have gone through Semen Analysis test on 05-04-16. The result is asthenozoospermia. Sperm concentration 37 M/ml, total sperm count 55.5M/ejaculate, Motile count 09 M/ml, Progressive 3%. What to do?

    • Sandra FernándezBA, MA

      Hello Debasish,

      according to the results of your semen analysis, your sperm concentration is good. However, I’m afraid with only 3% of sperm with progressive motility achieving a natural pregnancy is not possible, since immotile sperm or with a reduced motility are unable to reach the egg and fertilize it. Even though we should take into account the remaining percentages of your semen analysis as well as the reproductive health of your wife, in principle the treatment of choice would be in vitro fertilization (IVF).

      I hope I have been able to help,


  2. Featured
    Senthil Kumar


    We are Married and TTC for 3 Years. Semen Analysis Results are as Follows:

    1. Sperm Count: 54Mil/ml
    2. Sperm Motility: 42%
    3. Sperm Morphology: 5%

    Would like to understand the Chances of Natural Conception and should i need to take any suitable medication to improve the parameters?

    • Andrea AbbadBSc, MSc

      Dear Senthil,
      Usually it is needed a more extended semen analysis to evaluate it properly. There are several important parameters that would be helpful, like volume, vitality and an analysis of the motility that allows to differentiate between the different types (progressive, non-progressive…).

      Even so, the sperm count and the motility are normal and would allow a natural conception. In the case of morphology, it can be analysed with different methodologies that have different reference values. For example, if the morphology has been assessed by the WHO method the cut point is 4% of normal forms or more. In this case, the morphology of your semen analysis would be normal. If it has been assessed by the Kruger method the cut point is at 14%, which would mean that, in your case, that parameter is altered. In order to solve this doubt, you should check the semen analysis report and look for the morphology reference values.

      Since the rest of parameters are normal, the morphology is the one that will indicate in your case if natural conception is possible. Since you have been 3 years trying to conceive if morphology is normal you should run other tests in order to determine the infertility causes. If it is altered it might be the cause of the infertility and it is advisable to contact a fertility specialist to extend the fertility study and be assessed about which treatment is the most suitable in your case.

      Best wishes.

  3. Featured

    I am 31 years old married male and we are attempting for baby from past 3 years with no success. My problem is with Sperm quality which is as follows;
    Sperm Count – 20million per cc
    Morphology – Normal -90%
    Forward Movement – 60%
    Non Linear – 40%
    No. of Motile Sperms – 3million per cc
    Non Motile-85%
    Motile – 15% (Active 10%, Weak-5%)

    What I should do for above such condition.

    • Andrea AbbadBSc, MSc

      Dear Herald,
      Motility problems can have several causes. Your doctor will tell you if you can take some vitamins or complements in order to enhance the sperm quality. If he thinks that those kind of treatments cannot improve quality the only alternative is to go to a fertility specialist in order to undergo a fertility treatment such as artificial insemination or in vitro fertilisation. Depending on your partner’s fertility and age the specialist will recommend one treatment or the other.
      I hope I have been able to help.

  4. Featured

    Hi Doctor,

    I am 44 years old. Here is my semen analysis:
    Appearance Grey
    Liquefaction Time 30mins
    Viscosity Viscous
    Volume 0.5ml
    Fructose Positive
    Ph 8.0
    Sperm Concentration 56
    Total Motility(PR+NP) 35
    Progressive Motility(PR) 25
    Non Progressive Motility(NP) 10
    Immotility(IM) 65
    Strict Morphology(normal forms,%) 40
    PUS Cells 2-3 /hpf
    RBC Nil /hpf
    Round Cells 3-4

    What is the chance of having a baby naturally? Can ICSI / PGD help?


    • Andrea AbbadBSc, MSc

      Dear Sandeep,
      Your semen analysis shows lower volume and motility than what is expected in a normal sample. This might lead into having some trouble to conceive naturally. Having a baby naturally is not impossible but, since it can be complicated to achieve, I recommend that you visit a fertility specialist.

      With your analysis result it is possible to perform FIV or ICSI, and PGD might not be necessary. Therefore, a fertility specialist would recommend some more tests, specially to you your wife, and then decide with all the result which is the technique that suits your case the best.

      I hope I have been able to help.
      Best of lucks.