Paternal exposure during pregnancy may affect man's ability to father a child

According to the California Teratogen Information Service (CTIS) Pregnancy Health Information Line, more studies are needed to evaluate men and the potential effect of illnesses, medications and lifestyle habits on fertility and pregnancy. For couples suffering fertility problems, the issue is linked to the potential father approximately 50 percent of the time. In close to a quarter of these cases, a specific cause is unknown.

"A paternal exposure is anything the father of the baby is exposed to before or during his partner's pregnancy," explained Christina Chambers, PhD, MPH, professor of pediatrics and director of the CTIS Pregnancy Health Information Line, a statewide non-profit that educates the public about exposures during pregnancy and is based at the University of California, San Diego School of Medicine. "Some exposures may affect a man's ability to father a child by changing the size or shape of sperm, the number of sperm produced or how the sperm work."

Studies have found associations with the following risk factors and either altered sperm with or without infertility, lower fertility and infertility:

•Occupational: Chemicals such as heavy metals, solvents, fumes (welding fumes).

•Physical agents: Heat, vibration, extremes in temperature and pressure.

•Radiation: Radiation and electromagnetic radiation (cell phones).

•Lifestyle: Cigarette smoking.

•Infection: Chlamydia trachomatis, a common sexually transmitted disease.

•Pollutants: PCBs (Polychlorinated Biphenyls). PCBs were banned by the EPA in 1979, but exist in the environment including landfills, lakes and streams.

"Dad is sometimes an afterthought when it comes to pregnancy," said Chambers. "But the bottom line is it's often just as important to consider dad's impact on a developing baby before, during and after pregnancy as it is mom's. What better time to remind the public of that significance than during Father's Day."