Sperm counts among western men are so low that there is a potential threat to fertility in some countries, according to a major study.
Scientists found that between 1973 and 2011 there was a 59.3% fall in the average amount of sperm produced by men in Europe, North America, Australia, and New Zealand. That is more than 50 percent decrease in less than 40 years.
What is Sperm Count?
The sperm count measures the number of sperm present in every millilitre of semen. A normal range is between 15 million to more than 200 million – a sperm count of less than 15 million is low. Having a low sperm count can make it difficult to conceive a baby naturally, as well as other problems such as poor sperm quality.
The Possible Reasons for the Decline
The study is an “urgent wake-up call” for health authorities to investigate the causes and prevent it from getting worse, said Dr Hagai Levine from the Hebrew University of Jerusalem, who worked on the research. The analysis did not explore 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, drinking, and obesity. But despite the decline, average sperm counts remained in the “normal” range, said Allan Pacey, professor of andrology at the University of Sheffield.
Richard Sharpe at Edinburgh University added: “Given that we still do not know what lifestyle, dietary or chemical exposures might have caused this decrease, research efforts to identify (them) need to be redoubled and to be non-presumptive as to cause.”
The findings, published in the journal Human Reproduction Update, have been described by some fertility experts as “shocking”. These new findings coupled with the fact that more women are waiting until their 30s to have children is causing a problem for those looking to conceive. Researchers also said that this research may be acting as a ‘canary in the coal mine’, signalling broader health risks for males due to the impact of modern living.
Daniel Brison, a specialist in embryology and stem cell biology at Britain’s Manchester University, said the findings had “major implications not just for fertility but for male health and wider public health”.
“An unanswered question is whether the impact of whatever is causing declining sperm counts will be seen in future generations of children via epigenetic (gene modifications) or other mechanisms operating in sperm,”
In contrast, no significant decline was seen in South America, Asia or Africa. Although it must be taken into consideration that fewer studies were carried out in these regions.