Male infertility is very common, affecting approximately one man out of every twenty. Male factor is present in almost half of all infertile couples and about one third of all IVF procedures are performed for male factor infertility. For most men the discovery that they are infertile comes as a total surprise.
The testes have two distinct roles. The first is to produce the male sex hormone, testosterone, which is important for providing sex drive, erections, strong muscles and basically giving a man a general feeling of well-being. All these things can be described as virility.
The second function of the testes is to produce millions of sperm every day, a process that occurs inside each testis. For most infertile men, it is only this process that is at fault and a reduced number or poor quality of sperm are produced.
Most infertile men produce low numbers of sperm, which may also show both poor swimming ability (called motility) and be abnormally shaped (morphology). In such men, only a small number of normally shaped motile sperm are likely to swim up the woman's fallopian tube into the vicinity of the egg and even then may be unable to fertilize the egg.
Why does this problem develop? We now believe that most cases are genetic. In other words, these men are born without the genetic information that would allow sperm production to occur normally. No treatment for men to improve sperm counts is likely to become available. IVF techniques offer hope though, as they require very much fewer normal sperm than does Nature.
In the remaining one third of infertile men, we can find a likely cause for their infertility including:
Finally studies have shown that sperm counts have declined worldwide. The alleged change is quite small (about 15%) and no cause has been confidently identified, however it is believed to be an environmental factor.
In conclusion while the causes of infertility are uncertain in many men, certain conditions can be identified and treated. These facts make it essential that all infertile men have their situation thoroughly investigated.
For more information on male infertility, download our official Fertility Guide.