A new study confirms that sperm counts of men in several locations, including North America, Australia, New Zealand and Europe, are down — and have been for years. According to the findings, in less than 40 years, collective sperm count among this group has declined more than 50 percent. The researchers also found that the decrease does not appear to be "leveling off."
The study was published July 25 in the journal Human Reproduction Update, and was led by researcher Dr. Hagai Levine, an epidemiologist, public health physician and faculty member of the Braun School of Public Health and Community Medicine of Hebrew University of Jerusalem.
Levine and his colleagues conducted a meta-analysis of 185 earlier studies on sperm count, which included 42,935 participants who provided semen samples between 1973 and 2011. The men in the studies were from 50 different countries.
The review found a significant overall decline in sperm concentration of 1.4 percent per year, with an overall drop in concentration of 52.4 percent between 1973 and 2011. Total sperm count dropped 1.6 percent annually and plummeted 59.3 percent overall during that same time. However, these declines were seen only in studies from North America, Europe, Australia and New Zealand. Researchers did not see the same drops in men living in South America, Asia and Africa.
"The findings suggest a we have a clear and present problem of men's fertility and health that we must address," Levine says via email. He also says there's not enough data from non-Western countries to explain why men there aren't experiencing the same steep declines, but he says similar declines are unlikely. "We do have enough data to say there is a significantly differing slope for non-Western countries."