When it comes to male fertility, length matters—the length between the scrotum and anus, that is. New research suggests that measuring a man’s “anogenital distance,” or AGD, is a fast, low-tech, relatively accurate method of getting an idea of the quality of a man’s sperm.
In a new study, University of Rochester professor Shanna Swan and her colleagues broke out the measuring tape and assessed the anus-to-scrotum distance of 126 men born in 1988 or later. The men whose AGD’s were shorter than the average of two inches were 7.3 times more likely to have low sperm counts than their more well-endowed…er, well-distanced, brethren. These men with shorter AGD’s also had low sperm motility and poor sperm morphology.
So why on Earth, you’re wondering, would this be the case?
As DISCOVER said in the 2008 article The Dirty Truth About Plastics, “Biologists recognize a reduction in the length between the anus and the sex organ as an external marker of feminization, easily measured because it is typically twice as long in males as in females.” This reduction in AGD “may be caused by exposure to endocrine-disrupting chemicals” in the womb; Swan’s previous research specifically implicated prenatal exposure to phthalates, a commonly-used chemical in plastics, shampoos, paints, and pesticides.
Noting that nearly a fourth of the men in the study had low sperm counts, Swan urges young men to whip out the rulers and measure themselves. “It’s non-invasive and anybody can do it,” she says. We’re willing to bet she’s at least half right.
DISCOVER: The Dirty Truth About Plastics
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Image: flickr / The Welsh Poppy