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What Is Azoospermia?

Men with no sperm in their semen have a condition called azoospermia. The average man has 100–300 million sperm in his semen, but if there is no sperm, it can be difficult for couples to get pregnant. 

There are two types of azoospermia:

  1. Obstructive Azoospermia (OA)
  2. Non-Obstructive Azoospermia (NOA)

We can diagnose azoospermia by performing at least two semen analyses in the laboratory.

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Obstructive Azoospermia

In obstructive azoospermia, a man’s testes produce enough sperm, but there is a plumbing problem that prevents the sperm from traveling out of the testes and entering the ejaculate in the urethra/penis.

Obstructive Azoospermia Causes

Vasectomy: The most common cause of obstructive azoospermia is from a vasectomy. The vas deferens, which carries sperm from the testicles to the urethra during ejaculation, has been purposefully cut in half during a vasectomy. Men choose to get vasectomies as a form of birth control. 

Cystic Fibrosis (CF): Cystic fibrosis is a congenital lung disease that can affect fertility. Nearly all men (95 percent) with cystic fibrosis (CF) don’t develop all or part of their vas and epididymis ducts on both sides of their testicles. This condition is called congenital bilateral absence of the vas deferens (CBAVD).

Both the vas deferens and the epididymis help transport sperm from the testes into the penis. Although these transportation tubes are missing, sperm is still produced (spermatogenesis) in each testis. In fact, sperm production is normal in 90 percent of men with CF and CBAVD.

The exact cause of CBAVD is unknown. But researchers think that the same gene mutations that cause the lung and pancreas problems with CF also cause these ducts to not form. CBAVD does not affect sexual performance or ability to make love. In fact, most people are not aware that they have CBAVD until they can’t conceive and look for treatment from a male-reproductive expert. Learn about genetic testing to see if you are a gene carrier for cycstic fibrosis.

Ejaculatory Duct Obstruction: Ejaculatory ducts allow sperm from the vas deferens and fluid in semen from the seminal vesicles to enter the urethra. These ducts can be blocked by congenital cysts (that some men are born with) or from inflammation and scarring from sexually transmitted infections.

Surgical Complications: Men who have had bilateral hernia repairs can have blocked or injured vas deferens. This prevents the normal flow of sperm into the ejaculate.

Phimosis: Narrowing of the foreskin that can block semen from coming out of the penis.

Scarring: Sexually transmitted infections can cause scarring.

Midline Congenital Cysts: These cysts block the vas deferens from emptying into the urethra.

Non-Obstructive Azoospermia

Non-obstructive azoospermia is a set of disorders that cause a man to produce abnormal sperm. All of these disorders either decrease production or cause no sperm production at all.

Causes of Non-Obstructive Azoospermia

Non-obstructive azoospermia can be subdivided into pretesticular and testicular causes. 

Pretesticular Non-Obstructive Azoospermia: All pretesticular conditions disrupt the hormones a man needs for normal sperm creation. If a man has any of these conditions, this means he can’t produce healthy, normal sperm.

Causes of pretesticular non-obstructive azoospermia include:

  • Hypogonadotropic hypogonadism—This is a problem with the pituitary gland where it doesn’t make the hormones needed to create sperm or testosterone.
  • Hypothyroidism.
  • Use of certain medications.
  • Elevated estradiol.
  • Kallman’s syndrome.
  • Certain rare types of pituitary tumors.

These conditions can usually be treated through medications you take by mouth or by injection.

Testicular Non-Obstructive Azoospermia: If you have testicular non-obstructive azoospermia, this means that something is preventing your testes from creating normal sperm. Many things can cause testicular non-obstructive azoospermia.

These conditions make up most non-obstructive azoospermia cases:

  • Varicoceles, or varicose veins in the scrotum, which disrupt sperm production in the testicle (but rarely lead to azoospermia).
  • Bilateral undescended testicles or cryptorchidism.
  • Testicular cancer.
  • Gonadotoxins, such as radiation, chemotherapy, and some industrial chemicals that are toxic to the testes or gonads.
  • Immunologic causes, such as post-pubertal mumps orchitis (when a man who has already gone through puberty develops a mumps infection inside his testicle(s)).
  • Sertoli-cell only syndrome (when the testis doesn’t have any sperm cells).
  • Incomplete development, where all of a man’s sperm can only reach a certain, incomplete stage of development.
  • Genetic syndromes, such as Klinefelters (this is when a man has an extra X chromosome, so they have XXY instead of XY).

Azoospermia Treatment

Obstructive Azoospermia Treatments

  • Vasectomy Reversal: Most men who’ve had a vasectomy in the past can still conceive by having a vasectomy reversal (vasovasostomy or vasoepididymostomy).
  • Testicular Sperm Aspiration (TESA): TESA is a procedure in which a needle aspirates (suctions out) sperm from testicular tissue. The sperm that is removed can be used for in vitro fertilization (IVF).
  • Transurethral Resection of the Ejaculatory Ducts (TURED): Men who have ejaculatory duct obstruction can have a TURED, a small surgical procedure performed with a camera to remove this blockage and help sperm flow to the natural channels.
  • Circumcision: Men who have a narrow foreskin (phimosis) that prevents the ejaculate from coming out of the penis can have a circumcision to remove the foreskin.
  • Surgical Correction for Scarring: Some men have scarring from sexually transmitted infections (STIs) that can cause sperm to get blocked inside the ducts. We can often treat scarring endoscopically. Your doctor will insert a scope through your urethra in the operating room while you are under general anesthesia and use an electrified loop to open up the blockage.

Non-Obstructive Azoospermia Treatments

Regardless of what’s causing your non-obstructive azoospermia, we approach treatment the same way. We start with a semen analysis and male endocrine profile (blood work). Then we use one or more of the following treatments:

Drugs/Medications: If you have low bioavailable testosterone,* we usually start you on clomiphene citrate or clomid. You remain on this drug for four months, and we repeat another semen analysis.

One in nine men will have their sperm return to the ejaculate after taking medication to return their testosterone to the normal range. Some men’s sperm don’t return to their ejaculate after taking medication.

However, taking medication to normalize testosterone doubles the chances of finding sperm during a surgical sperm extraction procedure called microsurgical testicular sperm extraction (microTESE).

Microsurgical Testicular Sperm Extraction (microTESE): We recommend microsurgical testicular sperm extraction (microTESE) for men who have adequate testosterone* during diagnostic testing. We also recommend microTESE for men who’ve taken medications to correct their testosterone for at least four months but still aren’t releasing any sperm during ejaculation.

During microTESE procedures, doctors can find sperm approximately 50–65 percent of the time.

*Note: Bioavailable testosterone is different from the total testosterone that many labs check.

Next Steps

If you would like to consult with one of our fertility specialists, contact us to make an appointment.