- Title: Sperm count falling sharply in developed world, researchers say
- Date: 2nd August 2017
- Summary: MANCHESTER, ENGLAND, UK (RECENT - JULY 2017) (REUTERS) (SOUNDBITE) (English) SCIENTIFIC DIRECTOR AT THE UNIVERSITY OF MANCHESTER DEPARTMENT OF REPRODUCTIVE HEALTH, PROFESSOR DANIEL BRISON, SAYING: "What this new study's done is taken all previous studies, nearly 200 of them, and combined them into one big so-called 'meta-analysis'. And by doing that they can rule out some of the other explanations. So if, for example, you have 50 studies in one country and they all show the same trend in declining sperm counts, including different counting methods in different groups of men, that makes it much more likely that it's real."
- Embargoed: 16th August 2017 16:58
- Keywords: Male intertility sperm count health public health
- Location: TEL AVIV & UNKNOWN LOCATION, ISRAEL/ MANCHESTER, ENGLAND, UK/ VARIOUS FILE LOCATIONS
- City: TEL AVIV & UNKNOWN LOCATION, ISRAEL/ MANCHESTER, ENGLAND, UK/ VARIOUS FILE LOCATIONS
- Country: Various
- Topics: Health/Medicine
- Reuters ID: LVA00A6SGSVVF
- Aspect Ratio: 16:9
- Story Text: Sperm counts in men from America, Europe, Australia and New Zealand have dropped by more than 50 percent in less than 40 years, according to researchers from the Hebrew University of Jerusalem.
The study, a meta-analysis bringing together a number of studies, points to a potential decline in male health and fertility.
"Our findings of sharp decline in sperm count among western men is the canary in the coal mine. It signifies that we have a serious problem with the health of men in the western world," said Hagai Levine, who co-led the work at the Hebrew University-Hadassah Braun School of Public Health and Community Medicine in Jerusalem.
The rate of decline is not slowing, added Levine.
"We also found, when we restricted the analysis to studies after 1995 in order to model the recent trend, we found that the trend is not levelling off. There is a continuation of the decline in sperm count, at least in the western world. We don't know enough about the non-western world," he said.
The analysis did not look at reasons for the decline, but researchers said falling sperm counts have previously been linked to various factors such as exposure to certain chemicals and pesticides, smoking, stress and obesity.
Studies have reported declines in sperm count since the early 1990s, but many of those have been questioned because they did not account for potentially major confounding factors such as age, sexual activity and the types of men involved.
Working with a team of researchers in the United States, Brazil, Denmark, Israel and Spain, Levine screened and brought together the findings of 185 sperm count studies from 1973 to 2011 and then conducted a so-called meta-regression analysis.
"What this new study's done is taken all previous studies, nearly 200 of them, and combined them into one big so-called 'meta-analysis'. And by doing that they can rule out some of the other explanations. So if, for example, you have 50 studies in one country and they all show the same trend in declining sperm counts, including different counting methods in different groups of men, that makes it much more likely that it's real," explained Daniel Brison from the University of Manchester's Department of Public Health.
The results, published in the journal Human Reproduction Update, showed a 52.4 percent decline in sperm concentration and a 59.3 percent decline in total sperm count among North American, European, Australian and New Zealand men.
The former measures the concentration of semen in a man's ejaculation, while the latter is semen concentration multiplied by volume.
In contrast, no significant decline was seen in South America, Asia and Africa. The researchers noted, however, that far fewer studies have been conducted in these regions.
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