Researchers discover a range of factors undermine sperm quality, male fertility.

MONTREAL, QUEBEC—While women hoping to conceive are often reminded of the relentless ticking of their biological clock and the declining quality of their eggs as they age, research is also pointing to concerns for prospective fathers. Male factors play a role in about half of the 15% of couples who are infertile, and scientists are finding that, in addition to aging, a variety of substances can undermine sperm quality. Such factors as smoking and other behaviors, certain medications, and exposure to environmental pollutants can play a role in compromising sperm quality and were the focus of studies reported at a joint meeting of the American Society for Reproductive Medicine and the Canadian Fertility and Andrology Society held here in October. Unlike aging, however, many of these potential risks to male fertility can be controlled.