Anogenital distance or AGD is the distance between the anus and the underside of the scrotum. Men with AGD that is shorter that 2 inches are more likely to have low sperm count, which becomes the most common cause of male fertility problems.
During the study conducted by the University of Rochester Medical Center, the scientists took measurements of the AGD in 126 men born in or after 1988. The results showed that shorter AGD increases male fertility problems by seven times.
It is still not clear what is the cause of short AGD in men, but previous studies suggest that exposure to certain chemicals such as phthalates during pregnancy may result in shorter AGD in boys.