French men are losing sperm, and not in the fun way, according to a new study in Human Reproduction. Researchers examined semen samples given by 27,000 French men at fertility clinics, and found that the average sperm concentration fell more than 32 percent between 1989 and 2005.
Those findings echo a growing heap of research going back to the 1970s suggesting that the semen quality of men in industrialized countries is steadily declining. The most commonly-cited explanation is chemicals in the environment. Bear in mind, though, the supposed sperm-concentration drop is not a settled matter - many of the studies over the years were poorly designed, had overly-small sample sizes or were otherwise flawed. But if the ranks of men's sperm are being thinned, for whatever reason, it could have serious implications for couples' chances of conceiving.