The Scientific Journals

By : Steve Mirsky

No wonder it’s “the city that never sleeps.” A study in the May issue of Fertility and Sterility showed that New York City leads the nation in sperm counts. Actually, the study found that the Big Apple outdoes only two other cities. But, more important, the findings contradict previous studies suggesting a global decline in sperm counts.

Unless you are one of those people who thinks Testicles was a hero of the Trojan War, you have probably  read about the possible link between falling sperm counts and chemicals that may behave like estrogens. A 1992 paper by Danish researcher Niels Skakkebaek noted that studies done around the world indicated that  sperm counts had fallen from about 113 million per milliliter in 1938 to 66 million per milliliter in 1990. Combine that with a rise in testicular cancer and genetic reproductive abnormalities in some countries, and experts began to worry that we were on our way to a future of infertility. Accounts of the controversy appeared in this magazine (which is published in New York).

The new study, by Harry Fisch and colleagues at the Columbia-Presbyterian Medical Center (which is in  New York), reports that what Skakkebaek took to be a worldwide decline may have been a  misinterpretation of natural geographic variations. “There are geographic variations in everything—cancer and  heart disease, for example,” Fisch says. “I would be more surprised if sperm counts were the same everywhere.”

Fisch looked at counts for about 1,300 men who had donated at sperm banks in New York, Roseville,  Minn., and Los Angeles between 1970 and 1994. Rather than diminishing, counts rose in New York and Roseville. The differences among cities, however, were striking. Los Angeles came in at 73 million per milliliter, Roseville at 101. Start spreading the news that New York, N.Y., came in at the top of the heap with  a whopping 132.

This New York talent could account for a misperception of an international decline—apparently, it’s not true that if you can make it there, you can make it anywhere. When Fisch examined the 1992 Danish paper, he  found that 94 percent of the men studied before 1970 were from the U.S., 87 percent of them from New   York. But after 1970, only half the subjects came from the U.S.—and only 25 percent of them were New  Yorkers. If geographic variations do exist in sperm production, then what appeared to be a ubiquitous decline may have been merely the result of a shift in study sites.

None of which explains New York’s explosive ability for sperm production. “We don’t know why New York sperm counts are highest,” Fisch admits. In what may or may not be a related story, New York was recently shown to lead the nation in obsessive-compulsive disorder. With so much sperm to count, this was perhaps obvious.