According to a new study, when it comes to sperm counts, French men aren’t what they used to be over two decades ago.

Researchers found that sperm count in French men has decreased substantially.  Between 1989 and 2005, the number of sperm in one milliliter of the average 35-year-old Frenchman’s semen fell from about 74 million to about 50 million – a decrease of roughly 32 percent.

“That’s certainly within the normal range, but if you think about it, if there continues to be a decrease, we would expect that we’ll get into that infertile range,” said Grace Centola, president of the Society for Male Reproduction and Urology in Birmingham, Alabama.

And the French aren’t the only ones who should be concerned about a lack of swimmers, say researchers.

Dr. Joëlle Le Moal, the study’s lead author from the Institut de Veille Sanitaire in France said “A decline in male reproduction endpoints has been suspected for several decades and is still debated all around the world. Geographical differences have been observed between countries, and between areas inside countries,” Le Moal and her colleagues write in the journal Human Reproduction that global analyses have found decreases in sperm counts, as did recent studies in Israel, India, New Zealand and Tunisia.

Centola, who wasn’t involved with the new research, told Reuters Health that she’s found similar results in a group of young sperm donors from Boston, too.

For the new study, Le Moal and her colleagues used a database of France’s 126 fertility clinics that recorded men’s semen samples from 1989 through 2005. Over the 16-year period, the researchers found there was about a 2 percent annual decrease in the number of sperm in one milliliter of the average man’s semen.

The researchers narrowed their study to 26,600 samples provided by men whose female partners were later found to be infertile. That, they say, minimizes the risk that the men had a fertility problem.

According to Centola, one would look at that and say it’s not all that much. It isn’t, but if it’s occurring on a yearly basis it can add up. Also she said that if this type of decrease continues, they will find that they will have young men that have low sperm counts

The World Health Organization defines anything over 15 million per milliliter of semen as normal. However, the study’s authors suggest that it may take longer for men with counts in the lower range of normal to conceive.

The researchers also found that there was an increase in the number of abnormally shaped sperm over the study period, which can also influence fertility.

Part of that finding, however, can be explained by scientists getting better at recognising misshapen swimmers, but not all of it.  “So both results are important,” said Le Moal.

Two recent studies have actually suggested that modern technology such as laptops may be capable of cooking sperm, but the new researchers suggest it could also be other environmental factors, such as increased exposure to harmful chemicals that may decrease sperm count.

But Le Moal said it’s also important to consider that men’s lifestyles may have changed over time. May be men have become more sedentary and/or heavier than they were, over two decades

Centola said that it is a combination of lot of things, such as environmental factors and eating habits.