Is that a bulge in your pocket or are you just trying to avoid fatherhood? A new systematic review of 10 studies finds that keeping cell phones near the crown jewels could damage a man’s little swimmers.

“Given the enormous scale of mobile phone use around the world, the potential role of this environmental exposure needs to be clarified. This study strongly suggests that being exposed to radio-frequency electromagnetic radiation from carrying mobiles in trouser pockets negatively affects sperm quality,” explained University of Exeter’s professor Fiona Mathews.

“This could be particularly important for men already on the borderline of infertility, and further research is required to determine the full clinical implications for the general population.”

Until now, the research on the existence of an smartphone-sperm apocalypse had been mixed. So, the team conducted a “meta-study” or study of studies, and found that cell phone usage was associated with an 8.1 percent descent in sperm motility (how fast the little guys swim) and 10 percent enlargement of sperm viability (if they can make it to the egg alive).

Seeing as how I may want to be a father some day, I wrote this piece with my cell phone at arm’s length (wink, wink). Then, I read the study’s concluding passage, while typing the story on my lap:

“Mobile phone exposure may form part of a cumulative effect of modern day environmental exposures, that collectively reduce sperm quality and explain current trends in infertility. For example, recent evidence found wi-fi from laptops also negatively affected sperm quality.”

So, it appears, for the sake of fatherhood, that Google and Apple’s wrist-based computers can’t come soon enough.