Australian men are included in a new study revealing sperm counts have declined by more than 50 percent in the last 40 years.
The major study led by Israeli researchers published in the journal Human Reproduction Update found the sperm concentration in men declined by 52.4 percent and the sperm count decreased by 59.3 percent between 1973 and 2011.
More than 43,000 men from Australia, North America, and Europe took place in the study with results confirming a decline in male reproductive heath that could cause fertility issues and reduce the monthly chance of conception.
Experts say lifestyle factors including obesity, diet and exercise could be to blame.
Reproductive toxicologist Dr Shaun Roman told the ABC while the role of diet and environment in an individual's lifestyle should be investigated further, we are not in crisis yet.
"It should be noted that it only takes one sperm to fertilise an egg and, on average, western men are still producing 50 million per ejaculate," Roman said.
While the study included men who didn't hold any concerns about their fertility and men who already have children, the report indicates an increasing percentage of men showing sperm counts below the infertility threshold.
No significant decline was reported in men from South America, Asia and Africa, possibly due to lack of data.