Cryptozoospermia – Definition, Causes, Treatment & Pregnancy

By (embryologist), (embryologist), (gynecologist), (embryologist), (embryologist), (psychologist) and (biochemist).
Last Update: 04/08/2023

Cryptozoospermia or cryptospermia is a severe alteration of sperm concentration and, therefore, a cause of male infertility.

For male sperm to be of good quality, it must have an adequate number of spermatozoa with progressive motility and good morphology. Specifically, the World Health Organisation states that a semen sample should have at least 15 million spermatozoa per mL of ejaculate.

Men with cryptospermia have minimal sperm concentration, which makes natural pregnancy virtually impossible.


Cryptozoospermia is defined as a very low sperm count in the ejaculate. In fact, it is often confused with azoospermia, that is, the total absence of sperm in the ejaculate.

In particular, a man is diagnosed with cryptozoospermia when his sperm count in lower than 100,000 sperm per milliliter.

Although the World Health Organisation (WHO) has published an update of the Laboratory Manual for Semen Testing and Processing in 2021 (the sixth edition), the criteria of the fifth edition (2010) are the most common.

With this in mind, the WHO states that for a male to be considered to have a normal sperm concentration, it must be equal to or greater than 15 million spermatozoa per millilitre.

Cryptozoospermia is a less common type of oligozoospermia, which also refers to low sperm count. A sample is diagnosed with oligozoospermia if the total amount of sperm ranges between 100.000 and 15 million sperm/ml. In other words, cryptozoospermia is a severe type of oligospermia, as the sperm count is seriously compromised.

In addition to the sperm count, sperm motility and morphology should all in normal ranges to acheive a pregnancy naturally. If this is not the case, it would also indicate asthenozoospermia and teratozoospermia, respectively.

One should note that men with cryptozoospermia have only a few sperm in the ejaculate. For this reason, measuring the specific number of sperms that can move progressively or have a normal shape is almost impossible.

How is it diagnosed?

In order to evaluate the quality of a sperm sample, the most important test to carry out is a semen analysis or seminogram, which allows the sample to be examined both macroscopically and microscopically.

If alterations are found in the different sperm parameters, your doctor may require you to do some additional tests, including a hormonal analysis, physical exploration, and/or even an ultrasound scan. The goal is to gather as much information as possible to find the cause of infertility.

Assisted procreation, as any other medical treatment, requires that you rely on the professionalism of the doctors and staff of the clinic you choose. Obviously, each clinic is different. Get now your Fertility Report, which will select several clinics for you out of the pool of clinics that meet our strict quality criteria. Moreover, it will offer you a comparison between the fees and conditions each clinic offers in order for you to make a well informed choice.

Here are the most common tests performed to diagnose cryptozoospermia:

Sperm counting chamber

To determine the sperm count of a sperm sample, your doctor will examine the sample under the microscope aided by a counting chamber. Each chamber has a scored-in counting grid to make the sperm counting process easier.

There exist two types of sperm counting chambers nowadays:

Makler chamber
measures the quantity by millions per ml, however in cases of cryptozoospermia the count does not fit into that scale, so it becomes useless.
Neubauer chamber
It allows the specialist to accurately measure values of 10,000 spermatozoa per ml.

When a sperm specimen has cryptozoospermia, it is likely that no sperms or only a few are found under the microscope.

In these cases, the sample is centrifuged to eliminate seminal plasma and make the few sperms that are present to come into contact with the bottom of the conical centrifuge tube (this is called pellet). Then, the bottom of the tube is observed under the microscope in order to see if a sperm layer has formed.

Thanks to this technique, sperm can be found in the sperm sample in around 30% of cryptozoospermia cases.

Hormonal testing

There are two hormones that play a major role in male fertility. For this reason, monitoring their levels allows us to determine if spermatogenesis (process of sperm production) is taking place normally in the testes, or if there is a prevailing condition preventing it.

These hormones are FSH (follicle-stimulating hormone), released by the pituitary gland to regulate sperm production, and inhibin B, released by the testes once sperm cells are formed.

Here is what FSH and inhibin B levels can tell us about male fertility:

Normal levels of FSH and inhibin B
Spermatogenesis is taking place normally, hence a case of obstructive cryptozoospermia.
High FSH and low inhibin B levels
Testicular failure is compromising the sperm production process. This would be a case of non-obstructive cryptozoospermia.
Low FSH and inhibin B levels
The pituitary gland is not working properly, which affects spermatogenesis directly.  This would also be a case of non-obstructive cryptozoospermia.

Based on the type of cryptozoospermia (obstructive or non-obstructive), the treatment to try to increase the sperm count might vary.

Causes of cryptozoospermia

Discovering the particular causes of cryptozoospermia is a considerably difficult task. In most cases, the man is unaware that he has this sperm disorder until he starts trying to conceive.

However, the potential causes can be classified into the following groups depending on their origin:

Pre-testicular causes
alter the hormonal regulation of spermatogenesis, including conditions such as hypogonadism, or unhealthy habits (tobacco, alcoholic drinks, environmental toxics, etc.).
Testicular causes
affecting the testicles directly, including cryptorchidism, hydrocele, trauma, varicocele...
Post-testicular causes
causing obstructive cryptozoospermia, as they prevent the expulsion of sperm to the exterior. Examples include ejaculatory duct obstruction, absence of ejaculatory ducts, vasectomy, and urethritis (inflammation of the urethra).

The grade of severity of these causes will determine whether the man is suffering from oligozoospermia, cryptozoospermia, or azoospermia.

Is there a treatment for cryptozoospermia?

The potential solutions to cure cryptozoospermia depend on the cause or causes behind it.

On one hand, if it is caused by hormonal imbalances that affect sperm production, a hormone-replacement therapy might work to stimulate sperm production in the testes.

On the other hand, in cases where it is due to a testicular disorder like varicocele, fertility may be recovered through a surgical procedure.

Unfortunately, there are not many natural remedies to improve cryptozoospermia. However, males sperm quality issues should follow healthy lifestyle habits in any case, including a balanced diet, with foods that are rich in antioxidants, etc.

Taking Andean root powder is a common advice amongst men with poor sperm quality due to its multiple benefits for male fertility. However, its effectiveness has not been scientifically proven, and unfortunately it won't make natural conception possible in men with cryptozoospermia.

Cryptozoospermia & pregnancy

Men with cryptozoospermia who have been trying to conceive for a long time find it considerably difficult to achieve a natural pregnancy due to their almost non-existent sperm count. However, it is still possible, even if unlikely, as long as there are a few sperm live in the sperm specimen.

Experts recommend that couples who are trying to have a baby and find themselves in this situation turn to Assisted Reproductive Technology (ART). Particularly, IVF with ICSI (Intracytoplasmic Sperm Injection) is the most appropriate treatment.

With IVF/ICSI, there is only the need for the number of viable sperm to equal the number of oocytes able for fertilization. Nonetheless, the higher the number of sperm the better, to allow selection of the sperm with the best morphology and motility before proceeding with ICSI.

A potential complication with ICSI is that by the time the treatment is performed, the quality of the sperm decreases so much that no viable sperm is present in that moment.

In this case, couples have two possible solutions:

Egg vitrification
In order not to make the woman undergo another cycle of ovarian stimulation, the eggs obtained during the first IVF stimulation cycle are cryopreserved until viable sperm are retrieved.
Testicular biopsy
The doctor tries to retrieve sperm directly from the testis via testicular biopsy, a technique known as Testicular Sperm Extraction (TESE).

To prevent this situation occuring, it is recommended that men with cryptozoospermia store several samples of sperm containing viable spermatozoa before beginning the IVF cycle. In this way, it would be possible to turn to the frozen sample if the semen sample collected on the day of egg retrieval contains zero sperm.

In any case, one should keep in mind that ICSI is the fertility treatment indicated for males with cryptozoospermia.

FAQs from users

Can AI be performed if I have cryptozoospermia?

By Yolanda Galiana Briones B.Sc., M.Sc. (embryologist).

The answer is no. A semen sample diagnosed as cryptozoospermic is not suitable for artificial insemination (AI) treatment. The main reason is that at least 2 million motile spermatozoa are required after sperm capacitation to perform AI.
Read more

Is there a cure for cryptozoospermia?

By Ismael Vilella Amorós B.Sc., M.Sc. (embryologist).

Depending on the individual patient and the causes of cryptozoospermia, the fertility treatment will vary.

If the problem lies in the malfunctioning of some of the hormones and affects the creation of sperm, hormonal treatment may be prescribed to induce the functioning of the testicles.
Surgery may solve physical problems, such as undoing and/or correcting a vasectomy or treating varicoceles.

There is no treatment for poor semen quality. Healthy lifestyle advice can be given to correct bad habits and include dietary changes and antioxidant supplements.

What is the difference between cryptozoospermia and azoospermia?

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

It is not unusual that, when seeing that the sperm count is zero, sperm samples are diagnosed with azoospermia instead of cryptozoospermia.

The difference between azoospermia and cryptozoospermia is decisive, since a wrong diagnosis may lead to a testicular biopsy or epididymal sperm aspiration to retrieve sperm when there are viable sperms in the ejaculate, but only a few. The difficulty here is being able to find this few sperm in order not to be mistaken.

To avoid errors and provide the patient with the appropriate diagnosis of cryptozoospermia, the most advisable is to repeat the semen analysis. This time, the semen sample should be examined after having gone through a centrifugation process.

Is it possible to be a father, somehow, with cryptozoospermia?

By Paula Fabra Roca M.D., M.Sc. (gynecologist).

According to some studies, of the total number of sperm deposited in the vagina, only one in a million manages to reach the fertilization site (fallopian tube). Thus, in the case of ejaculates that have no more than 1-3 million spermatozoa, natural conception is practically impossible.

In cases of cryptozoospermia what is recommended is to perform In Vitro Fertilization (IVF) in which fertilization (union of the egg with the sperm) is performed by ICSI technology.
Read more

Is cryptozoospermia possible after vasectomy?

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

Yes, it is. When a man undergoes vasectomy, sperms do not vanish immediately from his ejaculate. It requires time, between 3 to 6 months or over, until the sperm count diminishes to zero and no sperm are found in the seminal ducts after various ejaculations. Throughout this timeframe, it is possible for the man to have cryptozoospermia.

If you liked this story, you may want to go through this: Post Vasectomy Semen Analysis – How Many Tests to Confirm Sterility?

By Marta Barranquero Gómez B.Sc., M.Sc. (embryologist).

Yes, IVF-ICSI is the best reproductive option for men diagnosed with less than 100,000 sperm per mL of ejaculate, i.e. cryptozoospermia.

This fertility treatment only requires the same number of sperm as eggs to be fertilised, so a large number of sperm is not necessary.

ICSI is the most adequate treatment option for men with cryptozoospermia. For more information about this technique,we recommend reading: What Is ICSI or Intracytoplasmic Sperm Injection?

As explained above, cryptozoospermia is considered a severe type of oligospermia, since the sperm count is significantly affected. To learn more about this you can visit the following page: What Is Oligospermia? – Low Sperm Count Causes & Treatment.

We make a great effort to provide you with the highest quality information.

🙏 Please share this article if you liked it. 💜💜 You help us continue!


F-Y Ku, C-C Wu, Y-W Hsiao, Y-N Kang. Association of sperm source with miscarriage and take-home baby after ICSI in cryptozoospermia: a meta-analysis of testicular and ejaculated sperm. Andrology. 2018 Nov;6(6):882-889. doi: 10.1111/andr.12546. Epub 2018 Sep 11 (View)

Julien Bessonnat, Sophie Brouillet, Sarah Sintzel, Pierre Gillois, Ulrike Bergues, Caroline Boutte-Busquet, Claire Thomas-Cadi, Sylviane Hennebicq. In cryptozoospermia or severe oligozoospermia is sperm freezing useful? Basic Clin Androl. 2014 Oct 2;24:15. doi: 10.1186/2051-4190-24-15. eCollection 2014 (View)

Natali Schachter-Safrai, Gilad Karavani, Eliahu Levitas, Michael Friger, Atif Zeadna, Eitan Lunenfeld, Iris Har-Vardi. Does cryopreservation of sperm affect fertilization in nonobstructive azoospermia or cryptozoospermia? Fertil Steril. 2017 May;107(5):1148-1152 (View)

Seda Karabulut, İlknur Keskin, Pelin Kutlu, Nuri Delikara, Özhan Atvar, Metin I Öztürk. Male infertility, azoozpermia and cryptozoospermia incidence among three infertility clinics in Turkey. Turk J Urol. 2018 Mar;44(2):109-113. doi: 10.5152/tud.2018.59196. Epub 2018 Mar 1 (View)

Tanja Grubić Kezele. Cryptozoospermia after treatment with clomiphene citrate following long-term use of intramuscular testosterone undecanoate depot injection. Horm Mol Biol Clin Investig. 2019 Mar 14;39(2):/j/hmbci.2019.39.issue-2/hmbci-2018-0078/hmbci-2018-0078.xml. doi: 10.1515/hmbci-2018-0078.

Wael Almajed, Mohannad Alharbi, Armand Zini. Use of mini-incision microdissection testicular sperm extraction in men with cryptozoospermia and non-obstructive azoospermia. Andrology. 2020 Sep;8(5):1136-1142. doi: 10.1111/andr.12795. Epub 2020 Apr 22 (View)

FAQs from users: 'Can AI be performed if I have cryptozoospermia?', 'Is there a cure for cryptozoospermia?', 'What is the difference between cryptozoospermia and azoospermia?', 'Is it possible to be a father, somehow, with cryptozoospermia?', 'Is cryptozoospermia possible after vasectomy?' and 'Is ICSI recommended for men with cryptozoospermia?'.

Read more

Authors and contributors

 Ismael  Vilella Amorós
Ismael Vilella Amorós
B.Sc., M.Sc.
Degree in Biotechnology from the Polytechnic University of Valencia. He has a Master's degree in Biotechnology and Reproduction in Mammals from the University of Murcia and has completed the first year of the PhD in Reproductive Health Biology "REPROBIOL" at the University of Murcia. More information about Ismael Vilella Amorós
License: 03194-CV
 Marta Barranquero Gómez
Marta Barranquero Gómez
B.Sc., M.Sc.
Graduated in Biochemistry and Biomedical Sciences by the University of Valencia (UV) and specialized in Assisted Reproduction by the University of Alcalá de Henares (UAH) in collaboration with Ginefiv and in Clinical Genetics by the University of Alcalá de Henares (UAH). More information about Marta Barranquero Gómez
License: 3316-CV
 Paula Fabra Roca
Paula Fabra Roca
M.D., M.Sc.
Dr. Paula Fabra has a degree in Medicine and Surgery and specializes in Obstetrics and Gynecology. She also has a Master's degree in Assisted Human Reproduction. More information about Paula Fabra Roca
collegiate number: 51123
 Yolanda Galiana Briones
Yolanda Galiana Briones
B.Sc., M.Sc.
Yolanda Galiana is the current coordinator of the IVF Spain laboratory. Yolanda holds a degree in Biology from the University of Alicante and, subsequently, a Master's degree in Assisted Human Reproduction from the University of Valencia. In addition, Yolanda is ESHRE certified and ASEBIR certified. More information about Yolanda Galiana Briones
Membership Number: 03102-CV
 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:
 Cristina  Algarra Goosman
Cristina Algarra Goosman
B.Sc., M.Sc.
Graduated in Psychology by the University of Valencia (UV) and specialized in Clinical Psychology by the European University Center and specific training in Infertility: Legal, Medical and Psychosocial Aspects by University of Valencia (UV) and ADEIT.
More information about Cristina Algarra Goosman
Member number: CV16874
 Michelle Lorraine Embleton
Michelle Lorraine Embleton
B.Sc. Ph.D.
PhD in Biochemistry, University of Bristol, UK, specialising in DNA : protein intereactions. BSc honours degree in Molecular Biology, Univerisity of Bristol. Translation and editing of scientific and medical literature.
More information about Michelle Lorraine Embleton

Find the latest news on assisted reproduction in our channels.