Get ready for a baby bust.
Sperm counts have fallen at an alarming rate worldwide — by more than 62% between 1973 and 2018 — and could lead to a reproductive crisis, new research finds.
During the same period, sperm concentration among men fell by more than 51%, from 101.2 million to 49 million sperm per milliliter of semen, according to the peer-reviewed study published Tuesday in the journal Human Reproduction Update.
That number is still above the World Health Organization limit of 15 million per milliliter, below which men are considered to have low sperm concentrations, The Times of Israel reported.
But the drop is still alarming, according to Prof. Hagai Levine of the Hebrew University of Jerusalem, who co-led the study with Prof. Shanna Swan at New York’s Icahn School of Medicine.
“We have a serious problem that, if left unresolved, could jeopardize the survival of humanity,” the epidemiologist said in a statement, adding that the findings serve as “a canary in a coal mine.”
The Israeli and American team, joined by researchers in Denmark, Brazil and Spain, studied sperm count trends in areas that had not been assessed before.
Levine noted that the news doesn’t address the cause of the decline, but other researchers have linked declining sperm counts to obesity, sedentary lifestyles, smoking, exposure to certain chemicals and pesticides, among other things.
In 2017, the same team reported an alarming drop in sperm counts in the Western world, according to Euronews.
It reported that sperm counts in America, Europe, Australia and New Zealand plummeted by more than 50% between 1973 and 2011.
The new study — which spans another seven years of statistics — is much broader in geographic scope, covering 53 countries, and the meta-analysis looked at 223 studies based on semen samples from more than 57,000 men.
The research also sounds alarm bells for both male fertility and men’s health in general, as low sperm counts are associated with an increased risk of chronic disease, testicular cancer and a shorter lifespan, the researchers noted.
“We should be surprised and concerned about the finding,” Levine told The Times of Israel.
“The downward trend is very clear. This is a remarkable finding and I feel a responsibility to deliver it to the world. The decline is both very real and appears to be accelerating,” he told the news outlet.
Levine cited research suggesting that fertility begins to decline when sperm concentration drops below 40 million per milliliter.
He said at the rate of the current decline, that number is expected to be the global average within a decade.
“In addition, we look at averages, and if men today have an average of 50 million sperm per milliliter, there are large numbers of men who today have less than 40 million sperm per milliliter – in other words, fertility that is actually suboptimal,” he told the Times of Israel.
Swan, of the Icahn School of Medicine in New York, said the plummeting sperm count is part of a broader decline in men’s health.
“The troubling declines in men’s sperm concentration and total sperm count of more than 1% per year reported in our paper are consistent with adverse trends in other men’s health outcomes,” she said.
“These include testicular cancer, endocrine dysregulation and genital birth defects, as well as declines in female reproductive health. Clearly this cannot go unchecked,” Swan added.