By Zaira Salvador BSc, MSc (embryologist).
Last Update: 11/28/2018

Teratozoospermia or teratospermia is a sperm disorder that indicates the presence of a high percentage of abnormal or defective sperm.

It is a cause of infertility in males, and the level of severity varies depending on the number of amorphous sperm in the semen.

Based on a set of criteria to determinate the severity of teratospermia, it can be classified into 3 different degrees: mild, moderate, and severe.

Classification of teratozoospermia

When a man is referred to a semen analysis to determine his fertility levels, the report will indicate the results of multiple seminal parameters, including sperm morphology.

A sample is classified as teratozoospermic when the percent of sperm with normal morphology is below 4%, according to the guidelines published by the World Health Organization (WHO) back in 2010.

Also, some laboratories use Kruger’s strict criteria to diagnose teratozoospermia. According to Kruger’s, a man is teratozoospermic when fewer than 15% of sperm has an abnormal shape.

Since the reference value established by the WHO is so low, determining the types of teratozoospermia based on the amount of normal sperm is senseless. Thus, in order to classify abnormal sperm into mild, moderate or abnormal, the Kruger’s criteria are more accurate than the WHO’s.

Mild teratozoospermia

A man has mild teratozoospermia when the number of normal sperm present in his semen ranges between 14% and 10%.

The remainder of the sperm sample has some kind of abnormality in the head, neck, or tail. In spite of this, the prognosis of men with mild teratozoospermia is still a positive one.

Should Assisted Reproductive Technology (ART) be needed to have a baby, both Intrauterine Insemination (IUI) and In Vitro Fertilization (IVF) would be possible, depending on the sperm count and motility.

The shape of sperm is crucial for fertilization to be possible. However, the good news is that men with mild teratozoospermia can still achieve a natural pregnancy.

Furthermore, there exist vitamin supplements containing vitamins and antioxidants that can promote sperm maturation, thereby improving sperm morphology.

See also: Treatment of Choice for Teratozoospermia.

Moderate teratozoospermia

Moderate teratozoospermia is diagnosed when the semen analysis report shows than just 9 to 5% of sperm have a normal morphology.

Unfortunately, conceiving with moderate teratozoospermia is unlikely. Men with this type of teratozoospermia may need to turn to IVF/ICSI to have children.

ICSI (Intracytoplasmic Sperm Injection) involves selecting the sperm under the microscope in order to inject it directly into the egg to cause fertilization.

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.

Severe teratozoospermia

When the test to determine sperm morphology reveals that less than 5% of sperm have a normal shape, the sample is diagnosed with severe or serious teratozoospermia.

Sperm with good morphology are so few that the chances of achieving pregnancy naturally are considerably low.

The rationale for this is that sperm with such a poor morphology have trouble moving forward, which translates into trouble reaching the egg and penetrating the zona pellucida (egg coat) in order for the male and female nuclei to fuse together. As a result, fertilization failure occurs.

The treatment of choice when a man has severe teratozoospermia is ICSI or its improved version: IMSI.

The IMSI procedure is the same as the ICSI one, but the difference is that it uses a special lens for the microscope, which enables an increase greater than 6300-fold of spermatozoa. Thus, sperm morphology can be observed in detail, which allows the selection process to be improved.

FAQs from users

Can severe teratozoospermia be cured?

By Zaira Salvador BSc, MSc (embryologist).

If the amount of normal sperm is fewer than 5%, the truth is that the chances for a natural pregnancy to occur are considerably low, and improving this situation with a natural remedy or medications is unlikely, too. Nonetheless, following healthier habits could improve it eventually.

On the other hand, if teratozoospermia is linked to other pathologies, such as varicocele, it is possible that the semen analysis report shows improved results after undergoing surgery to treat the varicocele.

What is isolated teratozoospermia?

By Zaira Salvador BSc, MSc (embryologist).

Isolated teratozoospermia is defined as having less than 10% of normal forms, based on Kruger’s strict criteria. A study published in 2003 showed that this type of teratozoospermia results in a lower cumulative birth rate compared to men with normozoospermia. (Spiessens C1, Vanderschueren D, Meuleman C, D’Hooghe T. Isolated teratozoospermia and intrauterine insemination, Fertil Steril. 2003 Nov;80(5):1185-9.)

Suggested for you

Depending on the type of teratozoospermia, that is, the degree of severity, a man may need to undergo fertility treatment to have children or not. To learn more, read: Achieving Pregnancy with Teratozoospermia.

The causes of teratozoospermia are varied and, more often than not, detecting them is a complicated process. If you are interested in delving deeper into this, do not miss this: What Are the Causes of Teratozoospermia?

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Auger J, Jouannet P, Eustache F. Another look at human sperm morphology. Hum Reprod. 2016;31(1):10-23.

French DB, Sabanegh ES Jr, Goldfarb J, Desai N. Does severe teratozoospermia affect blastocyst formation, live birth rate, and other clinical outcome parameters in ICSI cycles? Fertil Steril. 2010;93(4):1097-103.

Marchini M, Ruspa M, Baglioni A, Piffaretti-Yanez A, Campana A, Balerna M. Poor reproductive prognosis in severe teratozoospermia with a predominant sperm anomaly. Andrologia. 1989;21(5):468-75.

Perrin A, Louanjli N, Ziane Y, Louanjli T, Le Roy C, Gueganic N, Amice V, De Braekeleer M, Morel F. Study of aneuploidy and DNA fragmentation in gametes of patients with severe teratozoospermia. Reprod Biomed Online. 2011;22(2):148-54.

World Health Organization (WHO) (2010). WHO laboratory Manual for the examination of human semen and sperm-cervical mucus interaction. Cambridge Academic Press.

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Authors and contributors

 Zaira Salvador
BSc, MSc
Bachelor's Degree in Biotechnology from the Polytechnic University of Valencia (UPV). Embryologist specializing in Assisted Procreation, with a Master's Degree in Biotechnology of Human Assisted Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI). More information
License: 3185-CV
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  1. Featured


    I would like to understand 3 points from my seminogram:

    2-normal sperm @10% according to Kruger criteria

    The rest is OK.

    Is this an fertility issue?

    Appreciate your answer.

    • Sandra FernándezBA, MA

      Hello François,

      – Even though your pH levels are a little bit above the normal values, there is no evidence that it may have a negative impact on male fertility.
      – 10% of normal sperm is considered a normal value according to the WHO (in other words, that you are fertile).
      – A leukocyte concentration above 1mill/ml is considered a sperm pathology and may lead to trouble conceiving.

      In the majority of the case, an increased leukocyte concentration is due to some kind of infection and can be easily eliminated with antibiotic treatment.

      Best regards

  1. Aimen

    My husband has been diagnosed with severe oligoasthenoteratozoospermic sample. What treatment options can ensure pregnancy?

  2. santosh


    I got married 2 years ago. After few intercourses I am not able to father, so I went to a doctor and he suggested a semen analysis. I’ve got azoospermia and in pellet test I got oligoasthenotetrazoospermia with 100 % immotile. I got blood tests and my LH and FSH values are good. Please suggest me and mail me what to do. My wife’s got PCOS. Severe oligoasthenotetrazoospermia I think so. Please tell me what to do.

  3. John

    Hi, on my sperm analysis, I only have 1% normal but the volume is 132M. Vitality is 95%. Is the probablity of getting my wife pregnant in the natural way less likely or very low? Hence we have to resort to IVF? I hope you give me an opinion. Thank you.

  4. Sawsan

    There are a couple of things you can do to increase your chances. Have sex first thing in the morning, as that’s when his sperm count will be highest. Have him wear boxer shorts rather than briefs. You can try having him ejaculate into a cup and then use a syringe to shoot the sperm up against the cervix (it’s a bit of a nuisance but it may increase your chances). You can also try using a 1% vinegar douche just after sex as this will decrease the pH level and help push the sperm up to the cervix.