What affects sperm quality?

Age isn't the only impediment to male fertility; numerous other factors-many of which are controllable-can lessen sperm quality, according to the results of a number of studies reported at a joint meeting of the American Society for Reproductive Medicine and the Canadian Fertility and Andrology Society in October of 2005.

Those other factors appear to include use of anabolic steroids; cigarette smoking; nonsteroidal anti-inflammatory agents, such as ibuprofen; higher blood levels of manganese; and obesity.

In addition to examining which environmental, lifestyle, and medical factors influence male fertility, researchers are investigating how such factors cause infertility at the molecular level by evaluating sperm DNA. The hope is that down the road assessments of sperm DNA damage will serve as more accurate indicators of male fertility than conventional semen parameters, which are highly variable.