Almost every aspect of modern life from mobile phones to smoking, contaminating drinking water and contraceptives have been blamed for declining sperm counts and infertility, but no convincing evidence has emerged to link any of them to the problem.
Falling sperm counts have been presented by the media as a scare story about environmental chemical pollution, although, in reality, the causes remain unknown.
It will be critical to determine what the key differences between geographical regions are, such as genetic differences and exposure to specific pollutants, so we can then examine treatment strategies to limit these negative effects.
There is some evidence to show that maternal lifestyle during pregnancy can adversely affect sperm counts in adulthood. Prime among these is smoking, as several large studies have shown that moderate to heavy smoking during pregnancy reduces the testis size and sperm count of resulting offspring in adulthood.
There is also limited evidence that both alcohol consumption and obesity during pregnancy result in lower sperm counts in offspring in adulthood.
In the public eye, there is probably no doubt that perinatal exposure to environmental chemicals, in particular to ‘endocrine disruptors,’ accounts for falling sperm counts.
Based on the available evidence, there is insufficient evidence to conclude that exposure to Bisphenol A (BPA), at low to moderate levels, has a negative effect on reproductive outcomes in men.
BPA is a ubiquitous environmental toxicant with endocrine-disrupting properties and suspected to affect human reproduction.
There has been concern for a number of years about an increase in abnormalities in male reproductive health, such as testicular cancer. The decline in sperm counts is consistent with these increases and this adds weight to the concept that male reproductive health is under attack and is declining rapidly.
The men’s socioeconomic status also has a major impact on sperm quality.
Male factor issues such as low sperm count have to be seen in the context of female fertility, which is unarguably also on the decline for social and career reasons.
Doing nothing will ensure that couple fertility and average family size will decline below even its present low level and place ever greater strains on society.
We are still relatively ignorant about the causes of male infertility and as a matter of urgency, we need to increase, substantially, our research effort into male reproductive health.
We need much more research to find out why this decline in sperm count is happening. We cannot be complacent about the potential negative effect on fertility and must now urgently rally to substantially increase the research effort into male reproductive health.
We have no treatments for improving sperm production in infertile men and we have no idea about what is the cause of the condition. We cannot remedy it.