Men with smaller penises may struggle with fertility problems, according to a new paper due to be presented at the American Society for Reproductive Medicine conference in Colorado. Researchers found that infertile men tend to have penises that are nearly half an inch (one centimeter) shorter than that of their fertile peers.
“This is the first study to identify an association between shorter penile length and male infertility,” study author Dr. Austen Slade, a urologist and professor at University of Utah School of Medicine, told The Telegraph. “It’s possibly a manifestation of congenital or genetic factors that predispose one to infertility.”
Male fertility appears to be dropping around the world, with some studies estimating that men are only about half as fertile as they were four decades ago. Scientists aren’t sure why—population-level rates of male infertility have been blamed on everything from laptops, to poor sleep, to celiac disease. Until now, penis size hasn’t come up. But when Slade and his colleagues looked at the fertility and measurements of 815 men who visited a men’s health clinic between 2014 and 2017, they found that fertile men had penises around 5.3 inches long, erect, compared to infertile men, whose penises were an average of about 4.9 inches.
It’s a difference of only about one centimeter, in the final analysis—but it raised red flags for the researchers. “One centimeter may not be a striking difference,” Slade said. “But there was a clear statistical significance. It remains to be determined if there are different penile length cut-offs that would predict more severe infertility.”
It’s important to note that the findings are preliminary and have yet to be published in a peer-reviewed, scientific journal. For now the research, which is set to be presented this week at the American Society for Reproductive Medicine conference in Colorado, raises more questions than it answers and more research needs to be done before less endowed men panic, Slade noted. They have enough to be anxious about already.
“For now, men with shorter penises don’t need to worry about their fertility.”