What causes male infertility?

Male infertility is a condition that many men feel a bit embarrassed about. In his latest article, senior consultant in obstetrics, gynaecology and reproductive medicine Dr Simone Rofena explains the most common causes of male infertility, and some of the risk factors that you can avoid.

Is male infertility a common problem?

Yes, male infertility is a common condition, affecting approximately 7% of the population. In half of these men, the cause of their infertility is unknown.

What are the main causes of male infertility?

There are numerous possible causes of male infertility:

• One of these causes is a varicocele. This is when the veins that drain the testicle swell up. It is unknown why varicocele causes male infertility; however, it is believed to possibly be linked to abnormal blood flow.
• Another possible cause of infertility is an infection. Infections of different parts of the testicles, such as the epididymis or testicles, as well as STIs, can later lead to fertility problems. Sometimes the damage to the testicles from infections is permanent.
• Retrograde ejaculation is another medical condition that can cause fertility issues. This is when the sperm travels back up into the bladder during ejaculation instead of out of the penis. Retrograde ejaculation can be caused by injuries to the genitals, diabetes, spinal injuries, different medicines and bladder surgery. The tubes which carry sperm can also become blocked due to various possible problems, such as injury or infection.
• The immune system can sometimes mistake sperm for an intruder and attack them with antibodies.
• Both cancerous and non-cancerous tumours are another cause of male infertility problems. This can happen when the tumours are directly affecting the reproductive organs or one of the glands that secrete hormones necessary for reproduction.  Hormonal gland disorders can also lead to hormonal imbalances, which can cause male infertility.
• Certain medications can affect the sperm, such as anabolic steroids, cancer treatments and hormone replacement therapy (HRT) drugs.

Can genetic factors influence a man’s fertility?

Yes. In some cases, a clear link has been identified between a lower sperm count and a man’s genetics. Some of the genetic conditions and disorders that can affect a man’s sperm count or fertility include:

Y chromosome microdeletions: This is when some of the genes on the Y-chromosome are deleted, leading to problems such as the absence of sperm in the semen and other factors that can cause infertility in men.

Cystic fibrosis: Most people know that cystic fibrosis affects the lungs, but another symptom in men is the absence of the vas deferens, the tube that carries the sperm to the semen. Cystic fibrosis does not commonly cause problems with sperm production, in fact, most people with the disorder often have healthy sperm production. The problem is there is no way for the sperm to get inside the semen.

Klinefelter syndrome: Klinefelter syndrome, also known as XXY syndrome, is when men are born with an extra X chromosome. This is one of the most common causes of fertility problems in men. As it doesn’t affect daily life, many men with Klinefelter syndrome go through life undiagnosed, until they are assessed for infertility.

Kallmann syndrome: Kallmann syndrome is a genetic disorder that is characterised by a delayed or complete absence of puberty. It is rare, only affecting one in 30,000 men. Most men who suffer from this condition experience an absence of sperm production, and an impaired sense of smell.

Are there any risk factors I can avoid?

Yes. Sperm production can be affected by lifestyle factors, or overexposure to certain drugs, chemicals and toxins:

Tobacco and alcohol: Men who smoke have been shown to have a lower sperm count than non-smokers. Alcohol can also significantly affect male fertility, as it lowers testosterone levels, and can cause erectile dysfunction.

Drugs: The use of several different drugs can also affect sperm production. Anabolic steroids can cause testicle shrinkage, and lower testosterone levels. Marijuana and cocaine usage can also lower sperm production temporarily.

Industrial chemicals: exposure to industrial chemicals such as solvents, painting materials, pesticides and herbicides can lower sperm production.

Radiation/X-Rays: overexposure to radiation (including x-rays
or radiation therapy) can also increase the risk of developing fertility problems.

Obesity: Obesity can increase the chance of infertility in several different ways.

Dr Simone Rofena is a leading London-based gynaecologist, obstetrician and reproductive medicine specialist with over 15 years of experience. If you have concerns about male infertility, or any other reproductive or gynaecological condition, please don’t hesitate to book a consultation with Dr Rofena via his Top Doctors profile.