Oligoasthenoteratozoospermia is a pathological change in male sperm that often leads to infertility. The sperm changes are also known as OAT syndrome.


What is oligoasthenoteratozoospermia?

There is talk of oligoasthenoteratozoospermia when a man develops pathological changes in his sperm. In medicine, the phenomenon is also referred to as oligo-astheno-teratozoospermia syndrome or OAT syndrome. The term oligoasthenoteratozoospermia is composed of the words “oligo”, “astheno” and “terato”. See acronymmonster for Definition of Hyperplasia in English.

Oligo means “too little”. This means that there are no more than 20 million sperm in one milliliter of ejaculate from a man. The term astheno stands for “immobility”, which means that rapid locomotion is possible with less than 25 percent sperm. Only 50 percent of sperm make targeted movements. Terato is the term for “malformation”. A maximum of three percent of the sperm have a normal shape.

However, oligoasthenoteratozoospermia is only present if the three symptoms mentioned appear at the same time. More detailed investigations are needed to determine the causes of the symptoms. So there is a possibility that the infertility lasts only for a temporary period.


There are a number of possible causes for the presence of oligoasthenoteratozoospermia. So either the formation of the sperm is disturbed or there are difficulties with their transport. One of the most common causes of OAT syndrome is testicular malposition. Normally, these form around the position of the lower pole of the kidneys.

Between birth and the end of the first year of life, they move further into the scrotum. However, if there are problems with the descent of the testicles, it is possible that they settle in the abdomen or other parts of the body. Doctors then speak of a positional anomaly of the testicles. These can be sliding testicles or groin testicles.

Disorders of the testicles are sometimes congenital. These include testicular dystopias such as testicular retention and testicular ectopy, chromosomal defects such as Klinefelter syndrome, testicular hypoplasia and hereditary diseases such as cystic fibrosis. Hormonal disorders for oligoasthenoteratozoospermia such as FSH deficiency, LH deficiency, hyperthyroidism, hypothyroidism or a lack of testosterone are also possible.

Other conceivable causes include varicose veins in the testicles, prostate inflammation, inflamed testicles or epididymis after mumps, feverish infections or disorders of the sex chromosomes. Other possible indications are the consumption of drugs or alcohol, the use of certain medicines.

But venereal diseases such as gonorrhea or syphilis, radiation therapy for cancer, stress, a poor diet and being overweight or underweight can also promote oligoasthenoteratozoospermia. In some cases, however, no specific cause for the OAT syndrome can be found at all. Then there is talk of idiopathic oligoasthenoteratozoospermia.

Symptoms, Ailments & Signs

Oligoasthenoteratozoospermia can cause male infertility. The OAT syndrome can be recognized by the fact that the number of sperm is too low. Their mobility also suffers. It is not uncommon for the sperm to have an extensive malformation.

Oligoasthenoteratozoospermia is divided into three different degrees of severity from OAT I to OAT III. The classification of the degrees of severity depends on the concentration of the sperm:

  • In the case of OAT I, there is only a minor impairment of fertility.
  • In the case of OAT II, ​​on the other hand, there is already a significant limitation in fertility.
  • Doctors speak of OAT III when there is a severely restricted ability to conceive.

Diagnosis & course of disease

In order to find out the cause of the oligoasthenoteratozoospermia, the examining doctor takes care of the medical history of his patient. Of particular interest are possible diseases in the past, which can be considered as an impairment of fertility. These can be sexually transmitted diseases, diseases of the urinary tract or childhood diseases such as mumps.

After the anamnesis, the doctor performs a thorough physical examination. A sonography (ultrasound examination) is also carried out. The next step is to do a semen analysis to examine the semen.

A sugar determination, a penetration test and a membrane stability test are suitable as further diagnostic options. It is also useful to check the hormone levels in the blood. If no concrete causes can be found, it is not uncommon for some tissue to be removed from the testicles in order to examine it in a laboratory.

Oligoasthenoteratozoospermia does not always progress positively despite medical treatment. The affected persons are then still infertile. In such cases, artificial insemination can be useful.


In most cases, those affected suffer from infertility due to oligoasthenoteratozoospermia. This does not have to occur to a full extent, so that the affected person is only restricted in the fathering of children. In the worst case, however, complete infertility occurs, so that the patient cannot father children.

It is not uncommon for oligoasthenoteratozoospermia to have a very negative effect on the patient’s quality of life. Furthermore, tensions with one’s own partner can arise if there is a desire to have children. However, the rest of the patient’s health is not negatively affected or otherwise worsened by this disease. Life expectancy is also not limited or reduced by oligoasthenoteratozoospermia.

Those affected also have various other options for pursuing their desire to have children. Possible depression or other psychological complaints can be treated with the help of a psychologist or a therapist. Usually there are no special complications. Oligoasthenoteratozoospermia can only be treated if the disease is caused by another underlying disease. Possible inflammation can usually be treated well with the help of antibiotics.

When should you go to the doctor?

If sexually mature couples have an unfulfilled desire to have children, a doctor should be consulted. A control visit is advisable as soon as the planning of the offspring remains unsuccessful over a longer period of time despite all efforts. If all known guidelines for the conception of a child are followed and still no pregnancy occurs, a visit to the doctor to clarify the physical possibilities is advisable. Only men can contract oligoasthenoteratozoospermia, but it is advisable for both partners to have their fertility conditions examined by a doctor.

In addition, a comprehensive explanation of the individual state of health should take place so that possible optimizations can take place. This can help to alleviate mental stress and inner stress. If psychological problems arise as a result of the man’s infertility, a doctor is required. In the case of behavioral problems, depressive moods or persistent sadness, a doctor or therapist should be consulted.

If there are disorders of the libido, limitations in sexual function, reduced well-being or reduced zest for life, a doctor should be consulted. In the case of partnership problems or difficulties in coping with everyday life, the person concerned needs support. In many cases, therapeutic treatment can help so that the mental power of the person concerned can be strengthened and a realignment of possible life goals can take place.

Treatment & Therapy

The therapy of the syndrome depends on the cause of the oligoasthenoteratozoospermia. Since several symptoms can often occur simultaneously with this disorder, there is no standard treatment.

For example, if there is an infection, it will be treated first. Once the therapy is complete, another check will take place. If a varicose vein rupture is responsible for the OAT syndrome, a surgical procedure is carried out in which the testicular vein is ligated or sclerosed. In the case of a hormone deficiency, appropriate hormones can be administered to remedy the infertility.

If certain medications or stimulants are the cause of oligoasthenoteratozoospermia, the patient must refrain from consuming them. If the vas deferens is blocked, it is opened during a surgical procedure.

Another treatment option is testicular semen extraction (TESE), in which the patient’s sperm cells are surgically removed and used for artificial insemination.

Outlook & Forecast

Oligoasthenoteratozoospermia – also known as OAT syndrome – refers to a pathological reduction in sperm count. Genetic causes are often found to be the cause of this disorder. These cannot be influenced. The doctors treating you use a spermiogram to determine the extent and cause of the disorder.

In most cases, oligoasthenoteratozoospermia is about an unfulfilled desire to have children. In about half of the men affected by oligoasthenoteratozoospermia, the desire to have children can nevertheless become a reality. For the other half of those affected, the prognosis is rather poor. One of the problems with this is that the genetic malformations on certain chromosomes can be passed on to a male offspring. This would therefore suffer from the same disorder.

It therefore depends on whether the oligoasthenoteratozoospermia is caused by an insufficient number of sperm, or is defined by insufficiently motile or too many pathologically altered sperm. About 20 percent of men with oligoasthenoteratozoospermia have chromosomal or genetic fertility disorders. The chromosomally caused Klinefelter syndrome is often present.

Since genetic preconditions and genetic diseases can also lead to oligoasthenoteratozoospermia, the prognosis is usually no better than 50:50 if you want to have children. There are currently no treatment options for oligoasthenoteratozoospermia. Only in vitro fertilization can be attempted.


Preventing oligoasthenoteratozoospermia is difficult because its causes are not always known. Sometimes it can be useful to change your previous lifestyle and to avoid alcohol and anabolic steroids.


In most cases, those affected with oligoasthenoteratozoospermia have only a few and often limited follow-up measures available, so that a doctor should be consulted very early on in the case of this disease in order to prevent the occurrence of further complications. Self-healing of oligoasthenoteratozoospermia cannot usually occur, so that the patient is always dependent on medical treatment.

Most of those affected are dependent on a quick surgical intervention. There are no particular complications, although the patient should rest after the procedure and take care of his body. Here, exertion or stressful activities should be avoided in order not to unnecessarily burden the body. However, the disease cannot generally be completely cured, so that the affected person may become infertile even after an operation.

The further course of recovery depends very much on the time of diagnosis, so that a general prediction is usually not possible. The life expectancy of the affected person is not reduced by this disease. In some cases, contact with other people affected by the disease can also be useful, as this leads to an exchange of information.

You can do that yourself

Depending on the cause and severity, oligoasthenoteratozoospermia can be treated by those affected themselves. If the fertility disorder is due to causes such as obesity, malnutrition, stress or the consumption of stimulants such as alcohol and nicotine, a change in lifestyle is necessary. If there are hormonal disorders or diseases such as tumors, diabetes mellitus or a varicose vein fracture, these must first be treated. Physical activity is essential for psychological causes such as stress.

The affected men often also need therapeutic support. Couples therapy can also reduce possible conflicts in the relationship and, under certain circumstances, also contribute to an improvement in sperm quality.

In addition, the affected men must go to regular medical check-ups. The doctor will check the quality of the sperm at regular intervals and, if necessary, diagnose infertility. In many cases, however, the problems can be improved by consistently combating the causes. The urologist can answer which measures are useful and necessary in detail. If treatment of the possible triggers improves sperm quality, alternatives such as artificial insemination or adoption should be considered.