People who make their life's work understanding birth defects are among a group of women who face a high risk of giving birth to babies with physical problems, according to a study released Tuesday.
The study published in the journal Occupational and Environmental Medicine suggests that women working as biological and chemical scientists and pharmacists face an increased risk of giving birth to children with such defects as gastrointestinal, spinal and heart malformations compared to women in other occupations.
“Given those job titles, one would expect those women to work with different chemicals or something that could possibly be an exposure,” says Michele Herdt-Losavio, a researcher at the New York State Department of Health, who led the study.
Dr. Herdt-Losavio and her colleagues found that depending on a mother's occupation, a fetus would be more or less at risk of developing any one of 45 physical defects that are not DNA-related.
The study found that women working as janitors faced the highest risk of giving birth to children with certain defects, while teachers faced the lowest risk.
Researchers used data collected from over 9,000 mothers across the U.S. who gave birth between October, 1997, and December, 2003, to children with one or more of the 45 defects. The women were divided into 24 occupational categories, such as office workers, dry cleaners and those in manufacturing, and were compared with a control group of close to 4,000 mothers whose children did not have defects.
The researchers then focused on those who were working during the first trimester – what's known as the critical period, when birth defects are more likely to begin in a fetus.
Janitors were at a higher risk of giving birth to children with any one of seven birth defects, Dr. Herdt-Losavio explains, compared to the other occupations. Scientists' children had an increased risk of developing five of the defects.
“There were a few groups who had a mixture: they would be at risk for something or at a reduced risk for something else,” Dr. Herdt-Losavio says, citing cases in food service or health care.
The study did control for factors like smoking and alcohol consumption.
“It's just further evidence to point people in the direction where we should go from here,” Dr. Herdt-Losavio says.
A follow-up study will focus on those occupations with the most interesting results – such as scientists, janitors and teachers – to try to find out if there are particular environmental factors that affect risk levels.
“There's lots of questions that can be asked,” she says. “What do you do as a janitor? What products do you use? What hours do you work? How many hours do you work?”
However, Dr. Herdt-Losavio is careful to point out that right now, it isn't possible to make a clear link between an occupation and the likelihood of developing a birth defect: everything can somehow impact the development of a fetus. “No one study will ever really tell you cause and effect,” she says.
