Flagging Flagella

Male fertility is on the decline. Some startling statistics:

In 1992, Danish scientists published a meta-analysis of 61 studies on semen quality from around the world, concluding that the average sperm concentration had declined by nearly 50 percent over a 50-year period, from 113 million to 66 million sperm per milliliter. “Every man sitting in this room today is half the man his grandfather was,” reproductive biologist Lou Guillette told Congress in 1993. “Are our children going to be half the men we are?” …

In 2000, American researchers not only confirmed results from the original Danish semen quality study, they found sperm density in the United States and Europe to be falling at an even faster clip: by 1.5 to 3 percent per year. And last summer, an Israeli study noted a steady decline in semen quality at one local bank over the past 15 years. A full 38 percent of all sperm-donation applicants are now rejected, up from one-third prior to 2004. That year, the bank lowered its minimum sperm count for acceptance to widen its net for donors. Under those more stringent standards, 88 percent of contemporary samples would have been rejected.

Sperm-bank rejects aren’t necessarily infertile. But if the downward trend continues, by 2030 the researchers predict that even above-average men will reach “subfertility” levels. Globally, an average of 15 percent of men are considered infertile, up from 10 percent 20 years ago.