Teratospermia, also known as teratozoospermia, is an alteration affecting male sterility when more than 95 per cent of his sperm presents an strange or abnormal morphology.

The WHO considers that men with 4% of normal-looking sperm (at the very least) do not have any fertility problem. Conversely, a lower rate may indicate male infertility because of teratospermia. This reference value, which had been previously established at 14%, has changed in 2010. Thus, you may find other sites which say that it is considered that a man is suffering from teratospermia when he presents more than 85% of sperm with an abnormal morphology.

According to the Kruger strict criteria, if the amount of normal-looking sperm is equal to or greater than 15%, it is considered as normal. This criterion is always stricter than the one from the WHO, although the latter is the one taken as a reference worldwide. Unless otherwise stated, it is usually assumed that the values taken as a reference are those from the OMS and not those established by the Kruger strict criteria.

A morphological sperm analysis with a seminogram is used to identify this disease. A seminogram, a.k.a. spermiogram, consists of a test through which sperm morphology can be examined —either microscopic or macroscopic parameters— in order to determine a man’s sperm quality.

Sperm morphology is one of the many microscopic parameters analyzed by means of a seminogram. Generally, sperm are examined by counting a 100 sperms one after another. The fundamental sperm parts analyzed within this test are:

  • Head
  • Middle piece
  • Tail

Out of the 100 sperm selected randomly for examination, every abnormality found in any of the above mentioned parts of each one is written down. In case over 96 sperm present some sort of abnormality in one or various parts, the semen sample will be classified as teratospermic. If 4 or more than 4 normal sperm (i.e. no abnormality is detected in any of their parts) are found in the sample, the result of the sperm morphology assessment will be classified as normal.

Teratospermia and infertility

Having a poor sperm morphology may be a problem leading to male infertility since it can prevent the sperm not only from being able to fertilize the egg but also hinder embryo development in case the egg-sperm union takes place.

For problems related to sperm morphology, if there is a good concentration of sperm and no other problem exists, artificial insemination would be advisable. Conversely, if there were further problems or a poor concentration of sperm, IVF would be the best option. Finally, ICSI or IMSI are recommended for the most complicated cases of teratospermia.

IMSI is highly advisable en cases of severe teratospermia, since sperm with good morphology can be chosen previously to sperm microinjection thanks to image magnification. It is a conventional ICSI in which sperm are observed microscopically before being selected, but the difference is that the microscope has a lens amplifier that makes it easier to identify any morphological abnormality found on each spermatozoon.

If you are interested in getting further information about this male infertility cause, we recommend you to visit the following webpage: www.teratozoospermia.net


  1. usuario

    Is there any solution to sterility due to teratozospermia? I’m 36 and my wife and I have been trying to conceive for 2 years but no pregnancy yet… I did a seminogram and there was no sperm, I mean, my sperm count was zero. I couldn’t believe it so I did it twice, and still nothing. The thing is I had a problem on one of my testicles when I was a child and I underwent surgery, maybe is it linked to my infertility? I only beg you to clear my doubts, please.

    • avatar
      Sandra F.Fertility Counselor

      Dear Mark,

      The complete lack of sperm in the ejaculate is known as “azoospermia”. My recommendation is that you visit a fertility clinic so that an specialist determines whether it is a case of secretory or obstructive azoospermia. In the meanwhile, I invite you to visit http://www.azoospermia.info/ to delve deeper into it.

      Good luck

  2. usuario

    I just want to know the severity of this morphology
    Head: 89%
    Neck: 7%
    Tail: 2%
    The Dr. said it’s a minor case and not that serious since we just married and TTC 7months only. She just give a multivitamins.
    But since we knew this diagnosis we never read a successful rate of conceiving. We are anxious and really worried but the Dr. says just keep trying and don’t feel stress. How should we acknowledge this condition?
    Thank You

    • avatar
      Sandra F.Fertility Counselor

      Dear hope,

      I’m afraid I cannot read it properly, as you didn’t post the percentage of total malformation. Do you have it written on your semen analysis report? I need it to know for sure whether it’s teratospermia or not.

      I’m sorry!

      Best regards

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