Obstructive Azoospermia – Causes & Treatment Options

By (embryologist), (embryologist) and (fertility counselor).
Last Update: 12/13/2018

Obstructive azoospermia (OA), also called post-testicular azoospermia, is a cause of male infertility whereby no sperm are seen in a semen sample due to ejaculatory duct obstruction (EOD), responsible for allowing exit to the exterior.

It is the least severe type of azoospermia, and the one involving the lowest degree of infertility. Learn about your options to have a baby with obstructive azoospermia hereunder.

Most common causes

The causes of ejaculatory duct obstruction (EOD) are varied.

The following are the main ones:

  • Vasectomy: the seminal ducts are voluntarily blocked as a birth control method.
  • Surgical complications that caused a cut or blockage in the ejaculatory ducts.
  • Some congenital or genetic abnormalities can cause to failure in ejaculatory duct development. Bilateral cryptorchidism is an example.
  • Diseases like mumps or meningitis before puberty can block the ejaculatory ducts.
  • Inflammation, cysts or trauma, whether they occur in the testes, epididymis, prostate, urethra, or vasa deferentia.

Related post: What Are the Causes of Azoospermia?


Patients with obstructive azoospermia have normal hormone levels and testicular size.

For this reason, to verify that it is a case of obstructive azoospermia, the man has to undergo a series of seminal analyses and check whether his testes are able to produce sperm through a testicular biopsy.

A thorough palpation of the testicle can help the specialist to determine if there is spermatogenesis (sperm production) or not, although rendering a correct diagnosis before doing a biopsy is not possible.

The next step is to discover the exact location of the blockage. By doing this, we can determine the site where sperm can be collected from. The sample collected can be used in a fertility treatment to achieve a pregnancy.


The only treatment for obstructive azoospermia that can fix it is surgery. It basically involves reconnecting the conducts again to allow the passage of sperm again.

If surgery works, most males are able to expel spermatozoa again after a few months. Thus, they will have the chance of conceiving naturally, that is, without needing assisted reproduction to conceive a child.

As for natural treatments, there is no remedy that can work, as an obstruction cannot be repaired with a natural or medical therapy. Aside from a few exceptional cases, obstructive azoospermia requires surgery in almost all cases.

Pregnancy with obstructive azoospermia

As regards the chances of pregnancy, obstructive azoospermia is the less severe than non-obstructive or secretory azoospermia. In fact, there exist varios reproductive options for a man with obstructive azoospermia to be able to have genetic children, since spermatogenesis occurs.

As explained in the previous section, surgery is the first option in all cases of obstructive azoospermia. If achieving pregnancy is not possible after surgery, the most adequate fertility treatment will be determined.

What follows is a list of the potential alternatives available. However, should these options be unsuccessful, sperm donation is another possibility. To learn more about it, read: What Is Sperm Donation?

Testicular biopsy

A testicular biopsy is one of the main options for a man with obstructive azoospermia to have children. With a testicular biopsy, retrieving sperm that are capable of fertilizing the egg and result in a viable embryo is possible. The resulting embryo will be then transferred to the maternal womb, so that it is hopefully able to implant and cause pregnancy in the intended mother.

For fertilization to be possible in these cases, the technique used is IVF with ICSI (intracytoplasmic sperm injection). With this method, success can be achieved with just a single sperm cell. Given that with a testicular biopsy, neither retrieving a large amount of spermatozoa nor high-quality sperm is possible, ICSI is the only feasible option.

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.

Sperm aspiration

Another possible option, only viable in case the blockage is found in the vasa deferentia and not in the epididymis, is microsurgical epididymal sperm aspiration. It works similarly to a testicular biopsy: after retrieving sperm with this method, they are microinjected into the egg cell through ICSI technique.

A final option, although it is less common, it is also possible for a man with obstructive azoospermia to have biological children using ICSI with sperm collected via testicular sperm extraction. As in the case of epididymal sperm retrieval, it involves injecting a needle in the testicle, aspirating part of its content, and search for live sperm to be microinjected into the egg cell.

FAQs from users

Why does vasectomy cause azoospermia?

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

A vasectomy is a surgical procedure whereby the vasa deferentia are cut and tied. This causes sperm not to be expelled along with the semen during ejaculation, that is, it causes obstructive azoospermia.

Can cystic fibrosis cause obstructive azoospermia?

By Andrea Rodrigo B.Sc., M.Sc. (embryologist).

Cystic fibrosis is a genetic pathology that can affect the adequate development of sexual organs. For this reason, it can cause babies to be born without one or both seminal ducts.

Is a natural pregnancy possible with obstructive azoospermia?

By Andrea Rodrigo B.Sc., M.Sc. (embryologist).

Yes, it is possible in cases where a surgical procedure allows the passage of sperm through the vasa deferentia and epididymis again.

In any case, even though surgery can allow the passage of sperm, it is possible that sperm quality is insufficient as to fertilize the egg. For this reason, sometimes, in spite of having fixed the obstruction surgically, conceiving via assisted reproduction is still required.

Suggested for you

As already explained, a testicular biopsy can help both in the diagnosis and treatment of obstructive azoospermia. See this for more: What Is a Testicular Biopsy? – Purpose & Procedure.

You may also enjoy some further information reading this: What Are Your Chances of Achieving Pregnancy with Azoospermia?

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FAQs from users: 'Why does vasectomy cause azoospermia?', 'Can cystic fibrosis cause obstructive azoospermia?' and 'Is a natural pregnancy possible with obstructive azoospermia?'.

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Authors and contributors

 Andrea Rodrigo
Andrea Rodrigo
B.Sc., M.Sc.
Bachelor's Degree in Biotechnology from the Polytechnic University of Valencia. Master's Degree in Biotechnology of Human Assisted Reproduction from the University of Valencia along with the Valencian Infertility Institute (IVI). Postgraduate course in Medical Genetics. More information about Andrea Rodrigo
 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:
 Sandra Fernández
Sandra Fernández
B.A., M.A.
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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