Nov. 15, 2022 -- Sperm counts have been falling at a rate of 2.6% a year around the world, according to a new study.

One researcher involved calls it “an amazing pace,” adding that more men are likely to fall below the fertility threshold now compared to 50 years ago.

Building on past research, the study in Human Reproduction Update was based on more than 150 estimates from men who were probably not aware of their fertility. It says sperm counts dropped by 1.2% a year from 1973 to 2000 – and by 2.6% a year between 2000 and 2018.

“I think it’s a crisis, that we [had] better tackle now, before it may reach a tipping point which may not be reversible,” said Hagai Levine, MD, author of the research at the Hebrew University of Jerusalem in The Guardian.

It could result in some couples not having enough time to have all the children the want, he said.

Sperm counts aren’t falling enough to affect the human population, Amy Sparks, a reproductive physiologist at the University of Iowa, who was not involved in the research, told USA Today.

The new research isn’t "suggesting that our sperm concentrations are crashing at a rate that is going to lead us out to every man needing to walk into an infertility center,” she said.

"We don't understand why we're seeing this pattern, so I think it's hard to be alarmist for an individual," said Michael Eisenberg, MD, a urologist at Stanford University and Stanford Health Care. He was not involved in the new study.

One theory is that endocrine-disrupting chemicals or other environmental factors may play a role, acting on the fetus in the womb. Experts say factors such as smoking, drinking, obesity, and poor diet might also play a role, The Guardian reported.

Total sperm capacity is determined during fetal development, so exposures to human-made chemicals, stress and poor diet during pregnancy might all be contributing factors, Levine said.

Men’s fertility is more complex than sperm counts, and anyone concerned about his should consult his doctor. Overall health is important, such as eating right, exercising, and not smoking.

"I always tell men there's a strong link between fertility and health, so anything that's good for your heart is good for fertility," Eisenberg said.

Show Sources

Human Reproduction Update: “Temporal trends in sperm count: a systematic review and meta-regression analysis of samples collected globally in the 20th and 21st centuries”

The Guardian: “Humans could face reproductive crisis as sperm count declines, study finds”

USA Today: “Sperm counts are decreasing, study finds. What might it mean for fertility?”

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