When men become infertile

Male infertility is usually caused by problems that affect either sperm production or sperm transport. Photo: Shutterstock

The incidence of male factor infertility has risen from about 10%-15% to approximately 40%-50% in the last 10 years.

Worldwide statistics show that in male infertility, the majority of men have problems with either sperm production or sperm transport blockage, or a combination of both.

Sperm production

Problems with sperm production can either be non-inherited or inherited. The most common non-inherited causes are lifestyle related.

Cigarette smoke contains numerous chemicals that are harmful to sperm. The chemicals reach the sperm production “factory” (testicles) via the blood stream and affect the balance of certain proteins that are required for optimal sperm production and integrity.

This process damages the DNA of sperm via oxidative stress. Thus, a smoker may have a normal sperm count, but the quality of his sperm is very much reduced.

Alcohol abuse also reduces sperm production by lowering the level of the male hormone called testosterone. Testosterone is needed for optimal sperm production.

Many health organisations recommend men to avoid habitual or binge drinking. Research has not conclusively identified the amount of alcohol that affects sperm quality, but as little as five units (one alcohol unit is measured as 10ml or 8g of pure alcohol; this equals one 25ml single measure of whisky [40% alcohol content], or a third of a pint of beer [5%-6% alcohol content] or half a standard glass of red wine [12% alcohol content]) of alcohol per week has been shown to have a negative effect on sperm.

Besides alcohol, oral testosterone intake can reduce or completely stop sperm production. Testosterone that is consumed can halt the natural production of hormones that are essential for sperm production.

The reversal back to normality can sometimes take years.

Obesity is a well known risk factor for heart disease. However, what is less well known is that obesity affects sperm production by lowering testosterone.

This can happen because fat cells can turn testosterone into a female hormone called oestrogen. High levels of oestrogen can reduce sperm production.

In addition, the insulating effect of fat increases scrotal temperature, thus reducing the optimal environment for sperm production.

Obesity also can cause erectile dysfunction.

Stress affects a man’s fertility health. Men with high levels of stress have lower sperm quality.

How stress affects sperm quality is not fully understood but it could be related to the release of steroids called glucocorticoids, which lower testosterone levels.

It has also been proposed that stress damages sperm by oxidative stress.

Sexually transmitted infections (STIs) can also reduce sperm production by directly damaging the site of sperm production in the testicles.

Any man suspected to have an STI should seek appropriate consultation and treatment to avoid long term fertility health consequences.

Varicocele (dilated veins around the testicle) has long been proposed to reduce sperm production. However, only a moderate to large varicocele may impair sperm production by increasing scrotal temperature. Mild varicoceles do not reduce sperm production.

Failure of the testicles to descend into the scrotum during childhood (cryptorchidism) can lead to permanent damage involving sperm production. Testicles which failed to descend are in a “hotter” environment compared to its natural position in the scrotum. If treated surgically in early childhood, long term complications can be avoided.

Other less common causes of male infertility are injury to the genitals and medical treatment such as chemotherapy.

Sometimes, the cause is unknown. Inherited sperm production problems are rare. Conditions such as Klinefelter’s Syndrome, Y-Chromosome micro deletion and Down’s Syndrome can lead to either low sperm production or no sperm production (azoospermia).

Sperm transport blockage

In this condition, the sperm that is produced is unable to be ejaculated.

The ejaculate is a combination of semen and sperm. So, a man could still ejaculate out semen without any sperm (azoospermia).

The most common cause of a blocked sperm pathway is infections, especially STIs.

The inflammatory process damages the sperm transport pathway within and outside the testicle. However, most of the infections are asymptomatic and difficult to diagnose.

Prostate-related problem such as infection (prostatitis) or prostate surgery can lead to blockage. Other pelvic surgery, such as for inguinal hernia, can in some cases contribute to this problem.

In rare cases, the sperm transport channel is absent in a condition called cystic fibrosis. This condition is more prevalent in Western countries.

Sexual problems

Sexual problems lead to improper deposition of sperm in the vagina. Failure of ejaculation, erectile dysfunction, and retrograde ejaculation are some common examples.

Sexual problems can be due to an underlying medical condition such as uncontrolled diabetes mellitus.

Trauma to the spinal cord and pelvic or prostate surgery complicated by nerve damage can also lead to erectile dysfunction.

Hormones and sperm antibody

Diseases of the pituitary gland, congenital lack of hormones and Kallmann Syndrome can reduce the production of hormones needed for sperm formation. FSH (follicular stimulating hormone) and LH (luteinising hormone) are produced in the pituitary gland, and they drive sperm and testosterone production in the testicle.

Vasectomy (male sterilisation), injury or infection in the epididymis can lead to sperm antibody production. These sperm antibodies wrongly identify sperm as a foreign body and destroy the sperm.

Diagnosing male infertility

Diagnosis is based on a combination of clinical history, physical examination, semen analysis and additional hormone tests.

The first-line test is semen analysis (sperm test). Semen analysis looks at:

Sperm concentration: The lower range of normal is 15 million sperm for every millilitre of semen. Sperm concentration above this value is considered normal.

Vitality: This is the percentage of life sperm in the sample. It should be at least 58% (at least 58 out of 100 sperm are alive).

Motility: This parameter looks at the movement of sperm. At least 40% of the sperm should be moving. The movements are further graded according to speed and direction of movement.

Morphology: This parameter looks at the physical shape of a sperm. This is done under a high-powered microscope. At least 4% (you read it correctly!) of the sperm should be normal-looking to be considered “normal”.

Additional hormone tests are needed when there is no sperm (azoospermia).

A physical examination to look for any signs of testosterone deficiency, followed by blood tests for hormones (FSH, LH, testosterone), are done. The results will generally guide the fertility specialist as to the cause of azoospermia.

Treatment options

Sperm quality can be improved by lifestyle changes. The focus should be on reducing/stopping cigarette smoking, aiming for moderate alcohol intake, weight reduction, a healthy diet and reducing daily stress levels.

image: http://www1.star2.com/wp-content/uploads/2016/12/sfit_fitfertile0412_py_2.jpg

Photo: Reuters

Men should also consider adding antioxidants to their daily meal plan. Antioxidants potentially lower the level of oxidative stress on sperm, thus improving sperm quality.

However, any lifestyle modification will not show an immediate effect.

It takes at least two to three months before any improvement is seen because sperm production takes 72 days to complete.

Any improvement will be reflected in the new batch of sperm.

If azoospermia is due to vasectomy or obstruction, sperm can be obtained directly from the testicles. This requires a minor surgical procedure under sedation.

The severity of azoospermia will determine the type of surgical procedure required.