What Is Oligoasthenoteratospermia (OAT)?

By (senior embryologist), (embryologist) and (invitra staff).
Last Update: 06/25/2021

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

What reproductive options are available for oligoasthenozoospermia?

By Gustavo Daniel Carti M.D. (gynecologist).

The clinical picture of oligoasthenozoospermia refers to a combination of several factors. Specifically, it refers to a decrease in the quantity, motility and morphological alterations of spermatozoa.

For this reason, the best option for treatment and achieving pregnancy would be in vitro fertilisation with optimal sperm selection, i.e. IVF-ICSI.

Can oligoastenoteratozoospermia be cured?

By Emilio Gómez Sánchez B.Sc., Ph.D. (senior embryologist).

Oligoastenothermalospermia may be cured depending on its cause. For example, varicocele can be treated with surgery or hypogonadotropic hypogonadism with hormonal drugs.

In cases where the exact cause of oligoastenatozoospermia is not known, empirical treatment with antioxidants or antiestrogens may be used. These treatments must last at least three months and their effectiveness has not been proven.

Therefore, there are only a few patients with oligoastenothermia who can benefit from a specific treatment, the rest of patients could use empirical treatments and try to lead a healthy lifestyle. In most cases, assisted reproduction is the only treatment for them.
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Can you do IUI with oligoasthenoteratospermia?

By Zaira Salvador B.Sc., M.Sc. (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 B.Sc., M.Sc. (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.

Can oligoasthenoteraozoospermia cause miscarriages?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

Oligoastenothermalospermia is not directly related to abortion. However, it is possible that the sperm of these infertile males also possess genetic or chromosomal alterations that impede embryonic development once the embryo has already implanted.

How is oligoasthenoteratozoospermia diagnosed?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

Oligoastenothermospermia does not have any symptoms in men that might make them suspect that they suffer from male infertility. In order to make a diagnosis, it is necessary for the man to have a seminogram and to evaluate the parameters of concentration, mobility and morphology. Oligoastenatozoospermia is considered to exist when there are less than 15 million spermatozoa per millilitre, a mobility of less than 40% and a percentage of normal spermatozoa of less than 4%.

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

Cavallini G. Male idiopathic oligoasthenoteratozoospermia. Asian J Androl. 2006 Mar;8(2):143-57. doi: 10.1111/j.1745-7262.2006.00123.x.

Colpi G M , Francavilla S, Haidl G , Link K, Behre H M, Goulis D G , Krausz C, Giwercman A. European Academy of Andrology guideline Management of oligo-astheno-teratozoospermia. Andrology. 2018 Jul;6(4):513-524. doi: 10.1111/andr.12502.

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

De Braekeleer M, Nguyen MH, Morel F, Perrin A. Genetic aspects of monomorphic teratozoospermia: a review. J Assist Reprod Genet. 2015;32(4):615-23.

Francavilla S, Gabriele A, Oliveri M, Cordeschi G, Properzi G. Pharmacologic treatment of idiopathic oligoasthenoteratozoospermia. Acta Eur Fertil. Nov-Dec 1993;24(6):261-5.

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.

Góngora, A, Cortés-Algara, A, Cortés-Vásquez, A, Parra, LY. Infertilidad masculina causada por discinecia ciliar primaria. Síndrome de Kartagener.

Heidary, Z, Saliminejad, K, Zaki-Dizaji, M, Khorram Khorshid, HR. Genetic aspects of idiopathic asthenozoospermia as a cause of male infertility. Hum Fertil (Camb). 2018 Sep 9:1-10. doi: 10.1080/14647273.2018.1504325.

Nsota Mbango, JF, Coutton, C, Arnoult, C, Ray, PF, Touré A. Genetic causes of male infertility: snapshot on morphological abnormalities of the sperm flagellum. Basic Clin Androl. 2019 Mar 4;29:2. doi: 10.1186/s12610-019-0083-9.

Sermondade N, Faure C, Fezeu L, Lévy R, Czernichow S; Obesity-Fertility Collaborative Group. Obesity and increased risk for oligozoospermia and azoospermia. Arch Intern Med. 2012;172(5):440-442.

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

FAQs from users: 'What reproductive options are available for oligoasthenozoospermia?', 'Can oligoastenoteratozoospermia be cured?', 'Can you do IUI with oligoasthenoteratospermia?', 'What is the miscarriage rate with oligoasthenoteratospermia?', 'Can oligoasthenoteraozoospermia cause miscarriages?' and 'How is oligoasthenoteratozoospermia diagnosed?'.

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Authors and contributors

 Emilio Gómez Sánchez
Emilio Gómez Sánchez
B.Sc., Ph.D.
Senior Embryologist
Bachelor's Degree in Biology from the University of Seville. PhD in Biology from the University of Valencia. Large experience as an Embryologist Specialized in Assisted Reproduction. Currently, he is the IVF Lab Director of Tahe Fertilidad. More information about Emilio Gómez Sánchez
License: 14075-MU
 Zaira Salvador
Zaira Salvador
B.Sc., M.Sc.
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:
 Romina Packan
Romina Packan
inviTRA Staff
Editor and translator for the English and German edition of inviTRA. More information about Romina Packan

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