Nearly 1 in 7 couples is infertile, which means they haven’t been able to conceive a child even though they’ve had frequent, unprotected sexual intercourse for a year or longer. In up to half of these couples, male infertility plays at least a partial role.

Researchers assessed results of 185 male fertility studies between 1973 and 2011, involving almost 43,000 men.  The findings reveal that the concentration of sperm in the ejaculate of men in North America, Europe, Australia, and New Zealand fell on average 1.4% a year, leading to an overall drop of just over 52%.  Thus, it seems that male fertility has halved in less than 40 years.

Male fertility

Male fertility is a complex process.  To get your partner pregnant, the following must occur:

  • The body must produce healthy sperm: To produce healthy sperm you need the healthy development of male reproductive organs during puberty. At least one of the testicles should function correctly.  The body needs to produce testosterone and other hormones that trigger and maintain sperm production.
  • The semen should contain sperm: After the testicle produced sperm, delicate tubes transport the sperm until they mix with semen and are ejaculated out of the penis.
  • There needs to be enough sperm in the semen: If the number of sperm in the semen (sperm count) is low, it decreases the odds that one of the sperm will fertilize the egg. A low sperm count is fewer than 15 million sperm per millilitre of semen or fewer than 39 million per ejaculate.
  • You need good quality sperm: Sperm must be functional and able to move.  If the movement (motility) or function of the sperm is abnormal, the ability of the sperm to reach or penetrate the egg are very low.

Factors that can cause male infertility

Factors that cause male infertility are low sperm production, abnormal sperm function or blockages that prevent the delivery of sperm.

Medical factors include illnesses, injuries, chronic health problems, testicular deficiency, hormonal abnormalities, genetic abnormalities, certain medications, and other medical complications

Overexposure to certain environmental elements such as heat, toxins and chemicals can reduce sperm production or sperm function.  Overheating the testicles may impair sperm production and function.  Although studies are limited and are inconclusive, frequent use of saunas or hot tubs may temporarily impair sperm count.  Sitting for long periods, wearing tight clothing, or working on a laptop computer for long stretches of time also may increase the temperature in the scrotum and may slightly reduce sperm production.  However, the research isn’t conclusive.

Some lifestyle causes of male infertility include:

  • Drug use: Anabolic steroids taken to stimulate muscle strength and growth, cause the testicles to shrink and sperm production to decrease. Use of cocaine or marijuana can temporarily reduce the number and quality of sperm as well.
  • Alcohol use: Drinking alcohol can lower testosterone levels, cause erectile dysfunction, and decrease sperm production. Liver disease caused by excessive drinking also may lead to fertility problems.
  • Tobacco smoking: Men who smoke may have a lower sperm count than do those who don’t smoke. Second-hand smoke can also affect male fertility.
  • Weight: Obesity can impair fertility in several ways, including directly impacting sperm themselves as well as by causing hormone changes that reduce male fertility.

What is sperm motility and how does it affect fertility?

Sperm are motile cells.  This means that they are cells that make themselves move, which is important when it comes to getting pregnant.

Sperm are programmed to swim in a way that will help them reach their ultimate destination: the ovulated egg.  How sperm move is therefore important.  Progressive motility refers to sperm that swims in a mostly straight line or in very large circles.  Non-progressive motility refers to sperm that move but don’t make forward progression or swim in very tight circles.  Total motility refers to the percentage of sperm making any sort of movement.  This movement can include non-progressive movement.  For example, a sperm that just vibrates in place would be considered motile, but non-progressive.  A sperm that zigzags but makes forward progression would be considered progressive.  Progressive motility is needed in order for the sperm to swim their way up the female reproductive tract.

Sperm motility can be tested at a laboratory or at home.  Laboratory semen analysis provides you with both the total and progressive sperm motility information.  When selecting a home sperm quality test, it is important to select a test that measures the number of progressive motile sperm cells (PMSCs) or concentration per mL of the sperm cells that are able to swim and penetrate an egg.