Male Infertility Causes: A Patient's Guide to Diagnosis and Treatment Options

In short: Male infertility is one of the most common reasons for delay in conceiving and may have one cause or several. The main ones are hormone disorders (low LH and FSH or high prolactin), testicular problems such as varicocele, infection and genetic factors, blocked sperm ducts, erection and ejaculation problems, and semen abnormalities. Semen analysis and hormone tests help to find the cause and choose treatment.

Male infertility can stem from several different causes, ranging from hormonal imbalances to lifestyle factors. Understanding these causes can help you and your partner take the right steps toward diagnosis and, when needed, treatment. Below is a detailed, easy-to-follow overview of the main factors that can affect male fertility.

1. Causes related to the glands controlling testicular function:

• Delayed puberty.
• LH and FSH deficiency.
• Congenital hypo-gonadotrophic hypogonadism (deficiency of pituitary gland hormones), e.g. Kallman’s syndrome, which is associated with an abnormal sense of smell.
• Other causes that may result in damage to the pituitary and hypothalamic glands include:
• trauma
• irradiation
• tumors
• medications
• surgery.

Hyperprolactinemia due to a pituitary adenoma or as a side effect of certain medications can also play a role.

Measuring hormone levels (LH, FSH, prolactin, and testosterone) helps guide diagnosis. For example:

• Primary testicular failure is associated with a low testosterone level and high LH and FSH. This pattern is linked with either a low sperm count (oligospermia) or a complete absence of sperm (azoospermia).
• Retrograde ejaculation, an obstruction in the ejaculatory ducts, or germinal cell failure typically occur alongside normal testosterone, LH, and FSH levels.

In cases of LH receptor deficiency:

In this case, LH is high but the testes cannot respond to it, so testosterone stays low; in androgen insensitivity, by contrast, both LH and testosterone are high but the body does not respond to testosterone.

• If all of these hormones are low, this might be associated with other hormonal deficiencies, such as low growth hormone, low corticotrophin, or low TSH.

Based on these hormone levels, your treating physician can help pinpoint the underlying cause and recommend the most suitable next steps for you.

2. Testicular Disorders

• Idiopathic (unexplained) causes for testicular problems.
• Congenital causes.
• Chromosomal causes such as Klinefelter’s Syndrome (47XXY).
• Undescended testis (cryptorchidism), which may harm testicular tissue.
• Congenital absence of both testes.
• [Testicular varicocele: This is usually diagnosed through a physical examination, confirmed by Doppler ultrasound, and shows dilated veins in the spermatic cord above the testis. It can affect sperm production and quality. Repair is recommended when the varicocele can be felt on examination and the semen analysis is abnormal with no other cause for infertility, while small varicoceles found only on ultrasound usually do not need treatment.
• Major trauma to the testes.
• Severe testicular infection.
• Testicular tumors.
• Hazardous chemical or physical exposure.
• Medications such as cyclosporine, allopurinol, colchicine, sulfasalazine, and spironolactone.

Testosterone injections or gels and anabolic steroids (often used for bodybuilding): these switch off the testes’ own sperm production and can cause a very low sperm count or no sperm at all; recovery after stopping can take months to more than a year.

• Substance use, such as marijuana and alcohol, especially with heavy or long-term use, can affect sperm quality and slow motility.
• Some chemicals used in factories, such as the nematocide DBCP, along with lead and mercury, can affect sperm production.
• Chemotherapy used in cancer treatment.

All of the points above can affect sperm production or even cause a temporary arrest in sperm development.

• Smoking.

Smoking is known to affect sperm production, motility, and shape (morphology). Some researchers have found that smokers with varicocele may have a notably reduced capacity for sperm production compared with nonsmokers.

• Heat plays an important role in sperm production, so men are advised to avoid wearing tight underwear for long periods, as this may reduce sperm count.
• Jobs that involve long periods of sitting may also affect sperm count.
• Chronic medical conditions, such as chronic renal failure or chronic liver failure.
• Immunological disorders: these may trigger sperm antibodies that can harm sperm.

3. Disorders related to the epididymis, seminal vesicles, and prostate:

• Congenital causes: vas aplasia, malformation of the caudal corpus epididymis.
• Congenital obstruction of the seminal vesicles.
• Congenital obstruction associated with lung conditions, such as cystic fibrosis gene (CFTR) mutations, which cause congenital absence of the vas deferens; genetic testing of both partners is advised before ICSI.
• Severe infections may cause epididymal obstruction. Microorganisms that may cause such infections include Chlamydia and gonorrhea (especially in younger men), E. coli and other bacteria, and tuberculosis.
• Vasectomy: a procedure used for male contraception, in which the seminal ducts are cut, resulting in male infertility.

4. Coital Defects

• Inappropriate timing of intercourse (not around the time of ovulation).
• Erectile dysfunction: this could be due to psychological, neurological, or vascular disorders, or as a side effect of certain medications.
• Using certain ointments or creams during intercourse, some of which may harm sperm.
• Hypospadias: an abnormal position of the urethral opening.
• Congenital penile defects.
• Retrograde ejaculation: in these cases, semen flows backward into the bladder at the time of ejaculation instead of exiting through the urethra. This happens when there is a problem with the bladder neck due to:

A. Congenital causes:

• Stenosis of the external urethra.
• Stenosis of the external valve due to hypertonic muscles.
• Congenital anomaly of the internal valve.
• Congenital stenosis of the bladder neck.

B. Acquired causes:

• Neurological injury due to spinal cord injury.
• Pelvic fracture.
• Pelvic surgery.
• Diabetes.
• Prostate surgery.
• Bladder surgery.
• Urethral dilatation.

Certain medications, such as alpha-blockers used for the prostate (e.g., tamsulosin) and some antidepressants or antipsychotics.

C. Unknown causes.

5. Abnormal Semen

• Disorders affecting sperm and its ability to fertilize an egg.
• Immotile cilia syndrome.
• Necrospermia (dead sperm).
• Periaxonemal abnormalities.
• Increased viscosity of the semen above normal levels.
• Some factors that may suppress sperm function, such as a deficiency of an enzyme important for sperm motility (protein-carboxyl methylase, PCM).
• Zinc deficiency.
• Reduced levels of substances needed for sperm motility, such as adenosine triphosphate (ATP), or reduced use of ATP by the sperm.
• Sperm membrane malformation.
• Disorders in calcium metabolism.
• Lack of substances in the semen needed for sperm motility, such as bicarbonate, or abnormal levels of prostaglandins.

If you or your partner are concerned about male infertility, please know that you are not alone, and many of these causes can be identified with the right tests. A proper evaluation with hormone testing, semen analysis, and a physical examination can help pinpoint the underlying cause and clarify your options. Dr. Najeeb Layyous and his clinical team are available to guide you through the diagnostic process and discuss suitable next steps for your situation.

Common questions about male fertility

How does testosterone affect fertility?

The testes make both sperm and the hormone testosterone, under the control of two pituitary hormones, FSH and LH. This links testosterone to fertility in two ways:

·       Low testosterone: when testosterone falls because the pituitary gland is underactive (hypogonadism) or because of Klinefelter syndrome, sperm production drops. Weaker erections, low sex drive, and less body hair and muscle may come with it. Obesity, poor sleep and smoking also lower testosterone.

·       Taking testosterone: testosterone injections or gels, and anabolic steroids used for bodybuilding, switch off FSH and LH. The testes then stop making sperm, sometimes completely. Production usually returns after stopping, under a doctor’s supervision, but recovery can take months to more than a year.

This is why testosterone is not a fertility treatment and should not be used by a man who wants to have children. When a man has low testosterone and wants a pregnancy, the treatment is FSH and HCG together. Testosterone is measured with a blood test as part of the fertility work-up, together with FSH and LH. Our article on [male hypogonadotropic hypogonadism](/male-hypogonadotropic-hypogonadism/) explains this treatment in more detail.

Does having frequent erections mean a man is very fertile?

No. Erections and fertility are two different things. An erection depends on blood filling the spongy tissue of the penis, on healthy nerves and on how a man feels. Fertility depends on the testes producing enough sperm that move well and have a normal shape.

A man can have completely normal erections and desire and still have a very low sperm count, or no sperm at all. Easy or frequent erections, including morning erections, show that blood vessels and nerves are working, but say nothing about the number or quality of sperm. The only way to assess fertility is a semen analysis, as described in our article on [male infertility diagnosis](/male-infertility-diagnosis/).

Erection problems are worth discussing with a doctor, because they can be linked to diabetes, high blood pressure, high cholesterol or low testosterone. A painful erection lasting more than 4 hours is an emergency: go to the emergency department straight away.

Does having only one testicle mean a man cannot have children?

No. A man can father children with one healthy testicle, right or left, because it still produces sperm. The only way to be sure is a semen analysis, which checks how many sperm there are and whether they are healthy. If the other testicle is present but has not come down into the scrotum (an undescended testicle), see a doctor, because an undescended testicle can damage the testicular tissue.

Dr Najeeb Layyous F.R.C.O.G

Consultant Obstetrician, Gynecologist and Infertility Specialist