A new American study suggests that women working as biological and chemical scientists and pharmacists are more likely to give birth to babies with physical defects than other women.
According to the research, these children could suffer from gastrointestinal, spinal and heart malformations.
"Given those job titles, one would expect those women to work with different chemicals or something that could possibly be an exposure," the Globe and Mail quoted study' lead author Michele Herdt-Losavio from the New York State Department of Health, as saying.
Dr. Herdt-Losavio and her team discovered that the foetus could develop one of 45 physical defects unrelated to the DNA, depending on the occupation of the mother.
It was found that female janitors had the highest possibility of giving birth to children with certain defects, while teachers were in the lowest risk category. Scientists' children had more risk of suffering from five of the defects.
The scientists reviewed the information gathered from more than 9,000 mothers across the U.S. who gave birth to babies with one or more of the 45 defects, between October 1997 and December 2003.
The women were listed into 24 occupational categories like office workers, dry cleaners etc.
Thereafter, these women were compared to a control group of nearly 4,000 mothers whose kids were born without any disability.
Researchers then concentrated on those women who were working during the first trimester, which is a critical time when the foetus is more susceptible to develop abnormalities.
Talking about women working in food service or health care, Dr. Herdt-Losavio pointed out: "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 suggested that more studies had to be undertaken on the issue.
She said: "It's just further evidence to point people in the direction where we should go from here.
"There's lots of questions that can be asked.... 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 also explained that it is not possible to make a clear connection between a job and the likelihood of the child being born with defect.
She added: "No one study will ever really tell you cause and effect."
The study has appeared in the journal Occupational and Environmental Medicine.