Page URL:

French sperm counts drop by a third over 17 years

10 December 2012
Appeared in BioNews 685

Between 1989 and 2005 the sperm count of French men dropped by a third, according to research.

Compiling data from over 26,000 men, the study is thought to be the most extensive ever performed. It draws on data collected from French IVF clinics with researchers testing semen samples provided by men who were partners of women with diagnosed fertility problems.

In a paper published in the journal Human Reproduction, researchers note a continuous 32.2 percent decrease in total sperm count with an overall 33.4 percent decrease in healthy sperm.

The researchers say that their results 'constitute a serious public health warning'. The research will be added to other evidence that points toward declining male fertility in the industrialised world.

In the study, for men with average age of 35, semen concentrations declined from an average of 73.6 million per millilitre in 1989 to 49.9 million per millilitre in 2005.

Co-author Dr Joëlle Le Moal, an environmental health epidemiologist at the Institut de Veille Sanitaire, Saint Maurice, France, says that the values for 2005 'fall within the "fertile" range for men according the definition of the World Health Organisation'.

However, Dr Le Moal continues, 'the 2005 values are lower than the 55 million per millilitre threshold, below which sperm concentration is expected to influence the time it takes to conceive'.

The findings have been greeted with scepticism by some scientists who question the study's methodology. The researchers controlled their results for the effect that age has on semen concentration but not other variables.

Dr Allan Pacey, a senior lecturer in andrology at Sheffield University and chairman of the British Fertility Society, told the Guardian: 'I would urge much caution in its interpretation as there remain too many unknowns. In my view, the paper certainly does not resolve the issue of whether or not sperm counts have declined or not'.

In particular, Dr Pacey said that the paper claimed 'that the methods for measurement of sperm concentration and motility "have not changed noticeably during the study period", yet to me this is an odd thing to say as in my experience they have changed remarkably'.

Accordingly, Dr Pacey suggested, the decrease noted in the paper might just be 'a function of alterations to laboratory method'.

Contrastingly, Professor Richard Sharpe, at the Medical Research Council Centre for Reproductive Health at Edinburgh University, who was not involved in the study, said he did 'not accept that the basic methods for counting sperm have changed down the years, so there's no reason why sperm counts should go down unless it is real'.

Professor Sharpe added that the study meant it was 'time for action' and that research should be undertaken to determine the reasons for the supposed decline in male fertility.

'We still do not know which are the most important factors', he said, 'but perhaps the most likely is that it is a combination, a "double whammy", of changes such as a high-fat diet combined with increased environmental chemical exposures'.

31 July 2017 - by Dr Katie Howe 
Sperm counts of men in developed nations have fallen by 52 percent in the last 40 years...
4 April 2016 - by Ryan Ross 
Declining fertility rates in the West are partially a consequence of heightened competition for social status, according to an anthropological study...
19 October 2015 - by Lone Hørlyck 
Prenatal exposure to chemicals used in fracking for oil or natural-gas operations may affect sperm count later in life, a new study performed on mice suggests...
11 November 2013 - by Dr Rachel Montgomery 
High levels of air pollution are to blame for a distinct drop in semen quality in Shanghai, according to the doctor who runs the city's main sperm bank...
19 August 2013 - by David O'Rourke 
A US Government report shows that six percent of married couples in the USA have problems conceiving, down from 8.5 percent in a similar report three decades ago...
21 May 2012 - by Dr Victoria Burchell 
Exposure to low levels of environmental toxins may reduce male sperm counts, research in sheep suggests...
19 March 2012 - by Sarah Pritchard 
Men who consume a diet rich in saturated fat - the type found in junk food - have lower sperm counts than men whose diets contain low levels of such fats, according to scientists...
17 May 2009 - by Dr Sarah Spain 
A report written by leading reproductive biologist Professor Richard Sharpe from the Medical Research Council in Edinburgh, UK, has called attention to the dangers of chemicals present in household consumer products. The report concludes that exposure to a cocktail of hormone disrupting chemicals in our environment, particularly...
10 March 2008 - by Dr Charlotte Maden 
Two new studies have identified factors that could be causing a decline in male fertility. Research published in the journal Fertility and Sterility on the anti-impotence drug Viagra concluded that men taking the drug could be damaging their sperm and lowering their ability to conceive. Another study...
30 October 2006 - by Heidi Nicholl 
Researchers at Cornell Medical Center in New York have discovered that commonly prescribed anti-depressants may have the unwanted side effect of drastically lowering male sperm count. Tests were conducted on two men over a two year period, during which time their sperm count changed from normal before...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.