Sperm Counts Worldwide are Plummeting Faster Than Ever
upstart writes:
Sperm counts worldwide are plummeting faster than ever:
A 2022 meta-analysis found that sperm counts (the number of sperm per ejaculate) in humans have been dropping at an increasing rate in recent decades, reports National Geographic. A 2017 study found that sperm counts had "plummeted by more than 50 percent among men in North America, Europe, Australia, and New Zealand between 1973 and 2011." The newer study found that "not only has the decline in total sperm counts continued - reaching a drop of 62 percent - but the decline per year has doubled since 2000."
Shanna Swan, a reproductive and environmental epidemiologist at the Icahn School of Medicine at Mount Sinai in New York City, says the plummeting sperm counts could be attributed to multi-generational exposure to environmental chemicals.
From the study:
The initial study, published in July 2017, revealed that sperm counts-the number of sperm in a single ejaculate-plummeted by more than 50 percent among men in North America, Europe, Australia, and New Zealand between 1973 and 2011. Since then, a team led by the same researchers has explored what has happened in the last 10 years. In a new meta-analysis, which appears today in the journal Human Reproduction Update, researchers analyzed studies of semen samples published between 2014 and 2019 and added this to their previous data. The newer studies have a more global perspective and involved semen samples from 14,233 men, including some from South and Central America, Africa, and Asia. The upshot: Not only has the decline in total sperm counts continued-reaching a drop of 62 percent-but the decline per year has doubled since 2000.
[...] Contrary to common perception, infertility impacts men and women equally, says Amy E.T. Sparks, a reproductive physiologist and director of the IVF and Andrology Laboratories at the University of Iowa Center for Advanced Reproductive Health. "I think the perception that infertility is primarily a woman's problem may be due to the tendency for women to initially seek medical care for infertility rather than men." In the scientific community, the prevailing view is that male and female fertility challenges are each responsible for about one-third of infertility cases; the remaining cases are due to a combination of male and female factors.
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