Dads' jobs linked to birth defect risks

Certain jobs held by men in the months before they conceive a child may increase the risk of birth defects, a new study suggests.

Researchers analyzed information from more than 14,000 fathers whose jobs fit into at least one of 63 categories.

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The study found certain jobs were linked with an increased risk of multiple types of birth defects in children. These jobs included: mathematicians, physicists, computer scientists; artists; photographers and photo processors; food service workers; landscapers and groundskeepers; hairdressers and makeup artists; office and administration support workers; sawmill operatives; those working with oil and gas; those working in chemical industries; printers; those operating cranes and diggers; and drivers.

The researchers did not have information about chemicals or agents the men may have been exposed to at their jobs that could increase the risk of birth defects in their children, and so could not determine whether the jobs were indeed the cause of the defects.

However, the researchers pointed out that occupations in which workers are commonly exposed to solvents — such as artists, chemical workers, pharmacists, chemical engineers, painters, dry cleaners, printers and plumbers — were associated with an increased risk of eye, heart and intestinal defects, and oral clefts.

The findings mean that these jobs that should be investigated further for their potential to cause birth defects, the researchers said. The results can also help researchers figure out what types of chemicals commonly used in certain jobs might increase the risk of birth defects, they said.

Among children born in the U.S., birth defects occur in about 1 in 33 babies, according to the Centers for Disease Control and Prevention.

Andrew Olshan, of the University of North Carolina, Chapel Hill, and colleagues obtained the job histories of just under 10,000 U.S. dads who had a child with one or more birth defects born between 1997 and 2004, and job histories of just over 4,000 dads whose kids did not have birth defects. The jobs included in the study were those held by the father for at least the three months before conception and the first month of pregnancy.

The researchers classified the jobs into 63 groups, based on their assumed exposure to chemicals or other potential hazards.

The researchers examined the link between these jobs and more than 60 birth defects.

Nearly a third of job types were not associated with any increased risk of birth defects. These included architects and designers; health-care professionals; dentists; firefighters; fishermen; car assembly workers; entertainers; smelters and foundry workers; stonemasons and glass blowers; train drivers; soldiers; and commercial divers.

Jobs associated with specific types of defect included artists (associated with defects of the mouth, eyes and ears, gut, limbs, and heart), photographers and photo processors (associated with cataracts, glaucoma and absence of or insufficient eye tissue); and landscapers and groundskeepers (associated with gut abnormalities).

The study was published Tuesday in the journal Occupational and Environmental Medicine.