- Study warns the continued decline of sperm counts in men amounts to a crisis
- Researchers tracked sperm counts from across the world from 1973 to 2018
- They found sperm counts have more than halved in the last 46 years globally
Counts have more than halved since the 1970s.
And the decline has only accelerated since the turn of the century, according to a global analysis.
Scientists tracking the data, taken from 50-plus countries, said ‘we have a serious problem on our hands’.
Men’s bulging waistlines are blamed for the worrying trend, as well as ‘everywhere chemicals’ in the environment.
The warning comes on the day Earth’s population officially surpassed 8billion.
Experts predict the toll could even breach 10billion by 2100.
International researchers tracked sperm counts and concentrations from semen samples across the world between 1973 to 2018 by looking at older studies.
Men involved came from 53 countries including Britain, the US and Australia.
The analysis, which gives the first insight on trends in South America, Asia and Africa, also includes an additional seven years of data collection from 2011 to 2018.
Data included figures for sperm count and concentration in semen samples.
Count refers to the overall number of sperm in a sample, while concentration accounts for how many of the reproductive cells there are per volume of semen.
Results showed the mean sperm count fell by 51.6 per cent between 1973 and 2018 across men from all continents.
And concentrations have been falling by 2.64 per cent per year since 2000, quicker than the previous drop of 1.16 per cent annually from 1972.
Trends seen previously in men in North America, Europe and Australia have gotten quicker, the team said.
And they were also seen in those from South America, Asia and Africa, suggesting any future baby bust may not be limited to the global North.
Lead author Professor Hagai Levine, an epidemiologist at Hebrew University of Jerusalem, said: ‘Our findings serve as a canary in a coal mine.
‘We have a serious problem on our hands that, if not mitigated, could threaten mankind’s survival.
‘We urgently call for global action to promoted healthier environments for all species and reduce exposures and behaviors that threaten our reproductive health.
‘Overall, we’re seeing a significant worldwide decline in sperm counts of over 50 per cent in the past 46 years, a decline that has accelerated in recent years.’
While the current study did not examine the causes of sperm count declines, recent research indicates disturbances in the development of the reproductive tract in foetuses are linked to lifetime impairment of fertility.
He said ‘lifestyle choices and chemicals in the environment are adversely affecting this foetal development’.