Dad’s job may be linked to higher risk of birth defects

July 23, 2012
 
Dr. Tania Desrosiers

Dr. Tania Desrosiers

Historically, women have been the focus of attention when it comes to prenatal care — and appropriately so. After all, they are the ones carrying the baby. But fathers-to-be are not off the hook. In a new study published July 9 in Occupational and Environmental Medicine, researchers at the University of North Carolina at Chapel Hill found that certain jobs held by men before they conceive a child may increase the risk of various birth defects.

The study, led by Tania Desrosiers, PhD, in the UNC Gillings School of Global Public Health, is based on data from the ongoing U.S. National Birth Defects Prevention Study, which is investigating a range of potential risk factors for major birth defects in the largest population-based study of birth defects in the United States.
“The causes of most birth defects continue to elude researchers, yet birth defects are a leading cause of infant mortality and developmental disabilities in the U.S.,” said Desrosiers, a research specialist in the public health school’s epidemiology department. “We could stand to pay more attention to potential risk factors among fathers-to-be.”
Previous research has linked certain occupations to a general increase in the risk of birth defects, but this is the most extensive study to date that looks at so large a number of occupations and of birth defects, and analyzes which jobs are linked to specific defects.
Desrosiers and her team obtained the job histories of about 10,000 fathers who have children born between 1997 and 2004 with one or more birth defects and the job histories of 4,000 fathers of children born without birth defects during that period. They then classified the fathers’ jobs into 63 groups, based on the kinds of chemical and potential hazards to which the fathers were exposed. The study looked only at the fathers’ jobs three months before conception and during the first month of pregnancy, the four months considered a critical period for a fetus’ susceptibility to damage passed on in the father’s sperm.
The results show that almost one-third of jobs were not linked with a higher risk of birth defects in infants. These jobs included health care professionals, dentists, firefighters, architects and designers, car assembly workers, fishermen, entertainers, smelters and foundry workers, stonemasons and glass blowers, painters, train drivers and maintenance engineers, soldiers, and commercial divers.
However, certain jobs seemed to be associated with specific types of defects. Mouth, eyes and ears, gut, limbs, and heart abnormalities were associated with artists; whereas cataracts, glaucoma, and the absence of or insufficient eye tissue were associated with photographers and photo processors. Glaucoma and insufficient eye tissue also were associated with drivers, while gut abnormalities were linked to jobs such as landscaping and grounds work.
 
“Our findings imply that risk factors among fathers-to-be may play a significant role in their unborn child’s health,” Desrosiers said. “However, we do not advise men to change their jobs based on results from our study. More research needs to be conducted to understand why certain jobs seem to be associated with elevated risk.”
Media note: Tania Desrosiers can be reached at ta_desrosiers@unc.edu.
 

 
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UNC Gillings School of Global Public Health contact: Linda Kastleman, communications editor, (919) 966-8317 or linda_kastleman@unc.edu.