New research suggests the future of the human race may be at risk, with male sperm counts declining at an alarming rate.
Sperm counts amongst men in Western countries have more than halved in the last 40 years, although the reasons why remain unclear.
The concerning trend was identified by researchers who published their findings in a journal called the Human Reproduction Update. Their research consolidated 185 separate studies between 1973 and 2011, involving 43,000 men from around the globe.
Australians amongst the worst
The study suggests that over that time, the concentration of sperm in the ejaculate of men in Western countries has fallen by an average of 1.4% per year, resulting in an overall drop of just over 52%.
It found an even larger drop of 59.3 per cent in sperm counts amongst men from North America, Europe, Australia and New Zealand.
No significant decline was found in South America, Asia or Africa.
The reason for the drop is yet to be determined, and researchers agree that more research is needed to identify the underlying causes in order to work towards a solution.
Poor health affects sperm count
That said, health experts have consistently found a direct correlation between lack of good overall health and a decline in fertility, and point to the fact that Western men have poorer eating habits, engage in less exercise, and are more overweight, depressed, anxious and stressed than they used to be.
Smoking and high levels of alcohol consumption can also have an adverse effect on reproductive vitality.
The authors say the findings should act as an urgent wake-up call for researchers and health authorities around the globe, to investigate the causes with the goal of prevention.
The legal implications
Ultimately, lower sperm counts result in fertility problems.
When it becomes impossible to have a baby naturally, couples then look to other options such as IVF, sperm and egg donors and even surrogacy, which trigger legal issues around conception, birth rights, genetic selection and raising children.
Presently, surrogacy is not legal in Australia so couples end up completing the process overseas which can also be problematic.
Last year, an Australian nurse was at the centre of commercial child surrogacy allegations in Cambodia. She was alleged to have been taking advantage of emotionally distraught couples desperate for a baby, and poverty-stricken Cambodian women.
More than 70 Australian couples had to prove their legal parental rights to the Cambodian Government.
If sperm counts continue to fall, government may be forced to take a fresh look at the laws surrounding these issues.