What Is Oligoasthenoteratospermia (OAT)?

By BSc, MSc (embryologist) and BA, MA (fertility counselor).
Last Update: 03/01/2018

Oligoasthenoteratospermia (OAT) is the name of a sperm disorder in which three different sperm parameters are affected at the same time: sperm count, sperm motility, and sperm morphology. It is also known as oligoasthenoteratozoospermia.

The causes of OAT are varied, but in most cases they are linked to defects in the process of spermatogenesis (sperm production) or disorders in the male reproductive system, like varicocele or certain infections. As a consequence, achieving a natural pregnancy is considerably complicated for these men, and it is likely that fertility treatments like IVF are required.


The meaning of the term oligoasthenozoospermia is result of combining three different sperm disorders:

Low sperm concentration, less than 15 million/ml.
Poor sperm motility, more than 60 percent are immotile.
Abnormal sperm morphology, over 96 percent have an abnormal shape.

The reference values used to diagnose a semen sample with oligoasthenoteratospermia are the ones established by the World Health Organization (WHO).

Oligoasthenoteratozoospermia is, therefore, a cause of male infertility, as the poor quality of the sperms prevents them from being able to meet the egg and fertilize it.

Natural conception is not impossible if the results of the semen analysis are slightly below the reference values. However, the chances of achieving pregnancy diminish dramatically in men with OAT.


Determining the specific causes leading to oligoasthenoteratospermia is hard, mainly because it can be the result of a combination between different factors. Defects in the sperm production process (spermatogenesis), or disorders in the male reproductive system can diminish the sperm quality and cause male infertility.

It takes about 3 months for the process of spermatogenesis to complete fully. The process involves the division of the stem cells located close to the basement of the seminiferous tubules. Throughout the process, sperm go through different changes until they become sperm cells.

The following are some of the most common causes associated with oligoasthenoteratospermia in males:

  • Hormonal alterations affecting spermatogenesis
  • Consumption of certain medications, including anabolic steroids, antidepressants, and chemotherapy
  • Testicular birth defects
  • Testicular disorders, such as varicocele
  • Infections in the seminal ducts, like prostatitis
  • Genetic problems that affect sperm production

OAT can be treated differently depending on the cause. If it is caused by hormonal imbalances, certain medications can help the man recover his fertility again. In more serious cases, surgery may be needed.

However, the vast majority of patients with severe oligoasthenoteratozoospermia has no alternative but to turn to Assisted Reproductive Technology (ART) to become parents, as sperm disorders cannot be cured in most of the cases.


The treatment of OAT will be determined according to the factor or factors causing it. If it is caused by a serious disorder like varicocele, your physician may consider surgery as the best treatment option.

If the cause was a blockage due to an infection, treatment of antibiotics would be required. A medical treatment based on hormonal medications would be used should the cause be related to hormonal imbalances.

When OAT is due to idiopathic causes, that is, the etiology of the pathology is unknown, the most appropriate option would be a fertility treatment. Some patients, however, prefer to give a natural remedy a chance before moving on to ART.

Natural remedies

The first thing one should do right after obtaining an OAT diagnosis is to consider changing his lifestyle habits for a better health, including a balanced diet and moderate exercise. Quitting unhealthy habits is also crucial for improving the quality of your sperm in a few months.

Some vitamin supplements and natural remedies can be helpful as well. For example, maca root is a common natural remedy among men who suffer from OAT, although it might not work in certain cases.

Also, oxidative stress can have a highly negative impact on sperms due to the influence of reactive oxygen species (ROS), which compromise their functionality. For this reason, adding antioxidants such as vitamin E, vitamin C, and glutathione to your diet can help reduce the impact of oxidative stress.

Assisted Reproductive Technology (ART)

If pregnancy is not achieved after one year trying to conceive, or in cases of severe oligoasthenoteratospermia, fertility treatment may be required in order to become parents.

In cases of severe OAT, the technique of choice is IVF with ICSI (Intracytoplasmic Sperm Injection). Once the semen sample is collected, it is possible for embryologists to visualize the sample under the microscope and select the sperms with the best motility and morphology to inject them directly into the egg cell.

The main advantage of ICSI is that it allows for embryologists to make sure that egg fertilization has taken place and resulted in viable embryos. The resulting embryos that are considered viable will be transferred to the uterus of the prospective mother.

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.

Learn more: What Is ICSI or Intracytoplasmic Sperm Injection?

FAQs from users

Can you do IUI with oligoasthenoteratospermia?

By Zaira Salvador BSc, MSc (embryologist).

The pregnancy success rates of IUI in patients with OAT is too low. For this reason, these patients are directly referred to ICSI treatment, given that the chances of achieving pregnancy with other techniques are considerably low.

What is the miscarriage rate with oligoasthenoteratospermia?

By Zaira Salvador BSc, MSc (embryologist).

In principle, OAT is not associated with miscarriages. However, males with OAT can produce sperms with genetic or chromosomal diseases that prevent embryo development, that is, that cause the woman to miscarry.

Suggested for you

The male fertility test that is able to detect OAT is called semen analysis or seminogram. Read this post to learn how to interpret the results and the different aspects evaluated: What Is a Semen Analysis Report? – Purpose, Preparation & Cost.

To get an overall idea of the different sperm disorders that can be detected with a semen analysis, we recommend that you visit the following guide: Sperm Disorders that Cause Male Infertility.

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Authors and contributors

 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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