On Wednesday, the European journal Human Reproduction published the results of a vast French study carried out by the National Institute for Health Monitoring (INVS) revealing that "the concentration in spermatozoons of the sperm of French men declined by one third between 1989 and 2005." This study, the first carried out on the scale of a whole country and in France but also "probably in the world" according to the authors, involved "over 26,000 men tested over 17 years in centres for medically assisted procreation (MAP)." According to the results, "the number of spermatozoons in men aged 35 dropped from 73.6 million per millilitre of sperm in 1989 to 49.9 million/ml on average in 2005," that is a reduction of 32.2%. Furthermore, over the same period, "the study showed […] a significant reduction (33.4%) in the proportion of spermatozoons of normal shape." According to Dr Joelle Le Moal, an epidemiologist at the INVS and one of the authors of the study, "this is the first study to conclude that there has been a severe and general reduction in the concentration of sperm and its morphology on the scale of an entire country and over a long period."
Lastly, the authors of the study point out that "the reduction in the concentration of sperm could be even greater than what has been announced because the men attending the MAP centres have a priori a tendency to smoke less and not be obese, two factors known to harm the quality of sperm."