Study finds that dad’s job can influence birth defects
By Nancy Lamontagne
Although emphasis is often placed on how pregnant women can increase their chances of having a healthy infant, a large population study shows that men also play a role in their unborn child’s health. The new NIEHS-funded study found that men who worked in certain occupations, around the time of conception, were more likely to father offspring with various birth defects.
Epidemiologist Tania Desrosiers, Ph.D., of the University of North Carolina at Chapel Hill Gillings School of Global Public Health, led the research team. Although the study didn’t measure workplace exposures, the findings can be used to generate hypotheses about specific occupations and exposures for future research that incorporates exposure assessment.
The investigators looked for associations between paternal occupation and birth defects, using data from the National Birth Defects Prevention Study, which included 9,998 fathers of children with one or more birth defects, and 4,066 fathers of children without birth defects. Many previous studies on this topic have grouped occupations with varied exposures, but the new study individually examined more than 60 types of occupations.
“We examined nurses, dentists, and physicians, separately, which is important given that different exposures are encountered at each of these jobs,” said Desrosiers, a former NIEHS predoctoral trainee. “Likewise, we also considered over 60 types of distinct birth defects, whereas previous studies have often lumped together various defects, such as all heart defects, that may affect the same anatomic region, but are considered to have different etiologies.”
Job categories with increased birth defects
After considering other risk factors, such as education level, vitamin use, smoking, alcohol intake, and maternal age, race, and ethnicity, the researchers found an increased occurrence of various birth defects in several job categories. The occupations include mathematical, physical, and computer scientists; artists; photographers and photo processors; food service workers; landscapers and groundskeepers; hairdressers and cosmetologists; office and administrative support workers; sawmill workers; petroleum and gas workers; chemical workers; printers; material moving equipment operators; and motor vehicle operators.
Specifically, photographers and photo processors were more likely to father children with congenital abnormalities of the eye, while landscapers and groundskeepers were more likely to father children with gastrointestinal defects.
“We don’t advise fathers-to-be to change jobs, but it may be prudent to reduce or avoid unnecessary exposure to potentially harmful agents in the workplace,” Desrosiers said. “More research is needed to elucidate whether specific exposures found in the workplace, such as exposure to organic solvents or pesticides, for example, might account for the observed relation between particular jobs and birth defects.”
Since the study identified an increased risk of birth defects among children of fathers with several occupations that likely involve exposure to organic solvents, the researchers plan to investigate whether paternal solvent exposure is associated with birth defects, using data from a retrospective occupational exposure assessment performed on a subset of these fathers.
In addition to the NIEHS funding, the study was also supported by the Centers for Disease Control and Prevention.
Citation: Desrosiers TA, Herring AH, Shapira SK, Hooiveld M, Luben TJ, Herdt-Losavio ML, Lin S, Olshan AF, National Birth Defects Prevention Study. 2012. Paternal occupation and birth defects: findings from the National Birth Defects Prevention Study. Occup Environ Med. 69(8):534-542.
(Nancy Lamontagne is a science writer with MDB, Inc., a contractor for the NIEHS Division of Extramural Research and Training, Superfund Research Program, and Worker Education and Training Program.)