Sperm count amongst men worldwide is falling at an accelerated rate after halving during the last 40 years, a big recent study said Tuesday, calling for motion to stop the decline.

The study, led by Israeli epidemiologist Hagai Levine, updates 2017 research which had come under scrutiny for less than including North America, Europe, Australia and Latest Zealand.

The brand new study includes data from greater than 57,000 men collected over 223 studies across 53 countries, making it the most important meta-analysis ever conducted on the topic.

With the extra recent countries, it confirmed the 2017 finding that sperm counts have halved during the last 4 a long time.

Between 1973 to 2018, the concentration of sperm in men not known to be infertile fell by greater than 51%, from 101.2 million to 49 million sperm per millimetre of semen, the brand new study found.

“Moreover, data suggest that this worldwide decline is constant within the twenty first century at an accelerated pace,” said the study published within the journal Human Reproduction Update.

Sperm counts are dropping at a rate of around 1.1% a yr, the research found.

More motion and research is urgently needed “to stop further disruption of male reproductive health,” it added.

Sperm count just isn’t the one factor that affects fertility — the speed of sperm movement, which was not measured within the study, also plays an important role.

And the lower sperm concentration of 49 million continues to be well above the range considered “normal” by the World Health Organization — between 15 million and 200 million sperm per millilitre.

Sarah Martins da Silva, an authority in reproductive Medicine at Scotland’s University of Dundee not involved within the study, said it showed that the speed of decline in sperm count has doubled since 2000.

“And we genuinely do not know why,” she added.

“Exposure to pollution, plastics, smoking, drugs and prescribed medication, in addition to lifestyle, equivalent to obesity and poor food plan, have all been suggested to be contributory aspects although effects are poorly understood and ill-defined.”

Other experts said the brand new study didn’t resolve their scepticism in regards to the 2017 research.

“I remain concerned in regards to the quality of the information within the papers that were published, particularly within the far past,” on which the evaluation is predicated, Allan Pacey of the UK’s University of Sheffield told AFP.

While hailing the “very elegant meta-analysis”, Pacey said he believed we now have “simply gotten higher” on the difficult task of counting sperm, which could account for the falling rates.

But Martins da Silva dismissed critics of the study’s results, saying that “the numbers and consistent findings are difficult to disregard”.