THURSDAY, Nov. 15, 2012 (HealthDay News) -- Men with wide variation in the length of their sperm, particularly in the tail, have lower concentrations of sperm that are good swimmers, a new study indicates.
The finding could provide doctors with a new marker for fertility problems in men, the researchers suggest.
In the study, the investigators analyzed sperm from 103 men and found that those with sperm with longer overall length, longer tail length and higher tail-to-head length ratios had higher concentrations of sperm that are good swimmers. They also found that the greater the variation in sperm length, particularly tail length, the lower a man's concentration of sperm that could swim well.
"The finding could give clinicians new insight into the diagnosis and treatment of male fertility problems, which accounts for up to 50 percent of the cases where couples struggle to conceive," study lead author Jim Mossman, a postdoctoral scholar at Brown University in Providence, R.I., said in a university news release.
The results suggest that measurable variation in sperm length may be an indication of trouble with the process of making sperm, and that this trouble results in a lower concentration of sperm that swim well, Mossman noted.
The study was published online recently in the journal Human Reproduction.
It's not known what might cause sperm production problems that would result in inconsistent lengths of sperm or low concentrations of sperm that are good swimmers, Mossman pointed out in the news release.
"There are so many factors that govern sperm production, including environmental factors, genetic factors and their interaction," he said.
The Urology Care Foundation has more about male infertility.