What Is Oligospermia? – Low Sperm Count Causes & Treatment

By BSc, MSc (embryologist) and BA, MA (fertility counselor).
Last Update: 02/05/2018

Oligozoospermia or oligospermia is a sperm pathology that leads to male infertility. It affects the sperm count, which appears diminished on a semen analysis report in comparison with the results of males with normal sperm count.

Oligospermia can be mild, moderate, or severe depending on the sperm count, that is, the number of sperms present in the ejaculate.

A semen sample is considered poor in terms of quality when the sperm count is too low or there are other pathologies such as poor sperm motility (asthenozoospermia), or sperm morphology defects (teratospermia).


Oligospermia, also called oligozoospermia, is defined as having a low sperm count in the ejaculate.

Oligospermic semen samples are considered of poor quality, and males diagnosed with oligospermia are likely to experience trouble conceiving due to the low amount of sperms able to reach the egg. A poor sperm count reduces the chances for spermatozoa to meet the egg cell inside the female reproductive tract and fertilize it.

According to the World Health Organization (WHO), oligospermia is diagnosed when the total sperm count is lower than 15 million spermatozoa per milliliter of ejaculate.

To learn more about the different ways to evaluate the quality of a semen sample at the laboratory and the reference values taken into consideration, we recommend that you visit the following guide: Measurement of Sperm Quality.

Diagnosis & symptoms

Oligospermia has no physical signs or symptoms associated. Oligospermic men are able to have intimate relations as any other man, with full, normal ejaculations.

Typically, they realize that they have oligospermia when they start trying to conceive and pregnancy doesn't happen. It is at this point when they consider visiting a fertility specialist and take a fertility evaluation.

To examine the quality of a semen sample, fertility specialists use a test called seminogram or just semen analysis. Thanks to this diagnostic test, the different sperm parameters can be analyzed under the microscope. Particularly, the sperm count should be above 15 mill./ml for the sample to be considered normal.

A seminogram is typically done after 3 to 5 days of sexual abstinence, including any form of ejaculation aside from sexual intercourse. Semen samples are provided by masturbation.


The causes of oligospermia are varied, and can be classified into pre-testicular, testicular, and post-testicular factors depending on what leads to this disorder.

Oftentimes, finding the exact cause behind low sperm count is considerably complicated, since oligospermia can occur as a temporary alteration.

Pre-testicular causes

They include a series of factors that compromise sperm production (spermatogenesis) and can be related to the hormones that regulate sperm production or to external factors that have an impact on the body. Bad eating habits, tobacco consumption, alcoholic drinks, exposure to toxic environmental agents, or stress are some of the most common factors leading to low sperm count.

Testicular causes

They are caused by testicular diseases, including cryptorchidism, hydrocele, trauma in the genitalia, varicocele... Also, some genetic abnormalities, such as Y chromosome microdeletions (YCM), can have a negative impact on the testicular function.

Post-testicular causes

It refers to ejaculation problems, which is to say, the sperm production function works properly, but the problem appears when it is time for the man to ejaculate. Some examples include obstruction of the vasa deferentia, zero sperm count, or inflamed urethra (urethritis), as well as any other pathology leading to ejaculation issues.


There exist three classes of oligospermia: mild, moderate, and severe. The male patient will be diagnosed with any of them depending on how low his sperm count is.

Mild oligospermia
When the number of spermatozoa found in the semen sample ranges between 14 and 5 million sperm per milliliter.
Moderate oligospermia
The sample contains between 5 and 1 million sperm/ml. Great improvements can be achieved in these cases following the proper treatment and a healthy lifestyle for a few months. The semen analysis would be repeated after this timeframe.
Severe oligospermia
Less than 1 million sperm/ml are found. Pregnancy could be achieved only by means of Assisted Reproductive Technology (ART).

For the diagnosis to be accurate, the specialist needs to evaluate several semen analyses done in different weeks. This helps to dismiss the possibility that low sperm count is associated with long abstinence periods.


When the cause of oligospermia is unknown, leading a healthy lifestyle is the most appropriate treatment. This includes following a balanced diet, reducing or quitting toxic habits (alcohol or street drug consumption), and avoiding exposure to toxic environment agents or toxic workplace habits.

There are certain natural remedies that may help to deal with oligospermia, including certain herbs to consume as herbal infusions like damiana, tribulus terrestris, Asian ginseng capsules, or maca root powder. Given that they are just home remedies, their effectiveness has not been scientifically proved.

As for the medications to treat oligospermia, there exist vitamin supplements or hormone doses that can help improve sperm production. Their accuracy, however, has not been proved yet. Vitamins E, C and B6 have a great amount of antioxidants that protect the sperms from DNA fragmentation. Hormonal supplements are useful in patients with hormonal imbalances that affect the production of sperm, such as testosterone.

If no significant improvements are made, or if the causes of oligospermia are testicular or post-testicular, the best option to achieve a pregnancy would be to seek the most adequate infertility treatment.

How to get pregnant

Although oligospermia is a major cause of male infertility, men with low sperm count are still able to produce sperms and expel them with ejaculation. In other words, natural conception is still possible. The chances, however, diminish eventually as the sperm count becomes lower.

For this reason, a fertility treatment could be the best option for those couples who find themselves in this situation. Learn more about it in the following section.

Assisted Reproduction Techniques (ART)

The chances of achieving a successful pregnancy with ART depend on the severity of oligospermia. Moreover, if it is accompanied by another sperm disease, the odds will be even lower.

In cases of mild oligozoospermia, pregnancy could be achieved with intrauterine insemination (IUI), a simple, cost-effective technique that usually offers good outcomes. To be able to undergo IUI, it is required that the sample contains at least 2-3 million motile sperm after being processed via sperm capacitation. It is required that the woman is 35 or less years of age, without female infertility issues.

If IUI is unsuccessful or in case you have been diagnosed with moderate or severe oligospermia, the treatment of choice would be in vitro fertilization (IVF), either the classical type or IVF/ICSI.

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.

The steps to follow in a process of classical IVF or IVF/ICSI are quite similar—the woman receives ovarian stimulation treatment to produce multiple eggs, which are harvested from her ovaries by means of follicle puncture. Afterwards, fertilization is done in the laboratory.

In cases of severe oligospermia, ICSI is more effective than classical IVF, as only a single sperm cell would be necessary for fertilization to occur successfully.

FAQs from users

How often should you have intercourse with low sperm count?

By Zaira Salvador BSc, MSc (embryologist).

Many couples opt for having sex more often during peak fertility times in order to increase their chances of achieving pregnancy naturally. However, this may be an option only in cases of mild oligospermia. Moderate and severe cases should be treated through Assisted Reproductive Technology (ART).

Is having low sperm count hereditary?

By Zaira Salvador BSc, MSc (embryologist).

Yes, oligospermia is a male infertility cause that is commonly associated with genetic causes.

Can oligospermia be treated?

By Zaira Salvador BSc, MSc (embryologist).

Yes, as explained above, men with a diagnosis of oligospermia can still have genetic children. If it's a case of mild oligospermia, they can conceive naturally or by means of IUI. In moderate and severe cases, pregnancy could be achieved with IVF or IVF/ICSI.

Read: What Is In Vitro Fertilization (IVF)? – Process, Cost & Success Rates.

Can low sperm count lead to miscarriage?

By Zaira Salvador BSc, MSc (embryologist).

In principle, there's no reason why, although it is true that miscarriage can be caused by the sperm, too. A significant factor leading to recurrent miscarriage is low sperm quality as well as sperm DNA damage.

When does sperm count decrease with age?

By Zaira Salvador BSc, MSc (embryologist).

According to experts, it becomes noticeable after the age of 40 due to a decline in testosterone production. This loss of testosterone can lead to a decreased ability of the body for producing sperm cells and obtaining and/or maintaining an erection. All this makes the conception process longer and, when pregnancy is achieved, there's an increased risk of miscarriage.

How long would it take to get pregnant with low sperm count?

By Zaira Salvador BSc, MSc (embryologist).

It varies on a case-by-case basis, but chances are that it takes longer due to the presence of a lower amount of sperm in the ejaculate.

Can low sperm count cause quick ejaculation?

By Zaira Salvador BSc, MSc (embryologist).

No, there is no link between them. Low sperm count does not cause quick ejaculation, not vice versa.

Can low sperm count cause erectile dysfunction?

By Zaira Salvador BSc, MSc (embryologist).

Yes, it is somehow associated. Low testosterone levels go hand in hand with erectile dysfunction and low sperm count, as the hormones involved are the same.

Suggested for you

The only accurate test available today to evaluate whether a man is fertile or not is the semen analysis or seminogram. The WHO has established a series of reference values for parameters such as concentration, motility, and morphology in order to evaluate the quality of a semen sample. Want to learn more about this crucial test? Check this out: What is a Semen Analysis Report?

To learn more about male infertility testing, visit the following guide: Male Fertility Testing – How Do You Know if a Man’s Sperm Is Fertile?

Oligospermia is a sperm disorder that is defined as low sperm count. But there exist other sperm disorders depending on the parameter that is affected. Find them out here: Sperm Disorders that Cause Male Infertility.

Also, the following is a complete guide to fertility treatment options where you will find everything you need to know about IVF and other treatments. Read: What Are Infertility Treatments? – Definition, Types & Costs.

Our editors have made great efforts to create this content for you. By sharing this post, you are helping us to keep ourselves motivated to work even harder.


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Guzick DS, Overstreet JW, Factor-Litvak P, Brazil CK, Nakajima ST, Coutifaris C, et al. (2001). Sperm morphology, motility, and concentration in fertile and infertile men. N Engl J Med 2001; 345: 1388-1393.

Kirby EW, Wiener LE, Rajanahally S, Crowell K, Coward RM. Undergoing varicocele repair before assisted reproduction improves pregnancy rate and live birth rate in azoospermic and oligospermic men with a varicocele: a systematic review and meta-analysis. Fertil Steril. 2016;106(6):1338-1343.

McLachlan RI. Approach to the patient with oligozoospermia. J Clin Endocrinol Metab. 2013;98(3):873-80.

Meistrich ML. Effects of chemotherapy and radiotherapy on spermatogenesis in humans. Fertil Steril. 2013;100(5):1180-6.

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: 'How often should you have intercourse with low sperm count?', 'Is having low sperm count hereditary?', 'Can oligospermia be treated?', 'Can low sperm count lead to miscarriage?', 'When does sperm count decrease with age?', 'How long would it take to get pregnant with low sperm count?', 'Can low sperm count cause quick ejaculation?' and 'Can low sperm count cause erectile dysfunction?'.

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 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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