WEDNESDAY, July 12, 2017 (HealthDay News) -- More evidence of stress's harmful effects comes from a pregnancy study.
California researchers found that stress increases the risk that exposure to toxic chemicals in pregnancy will lead to a low birth weight baby.
"It appears that stress may amplify the health effects of toxic chemical exposure, which means that for some people, toxic chemicals become more toxic," said senior author Tracey Woodruff, a professor of obstetrics, gynecology and reproductive sciences at the University of California, San Francisco.
Woodruff and colleagues at UC Berkeley reviewed 17 human and 22 animal studies that investigated the links between chemicals, stress and fetal development.
The review found that several toxic chemicals commonly found in the environment had a much greater impact on pregnant women if they had high levels of stress. The researchers measured stress by factors such as socioeconomic levels and years of education.
The strongest connection involved smoking. High-stress women who smoked were about twice as likely to have a low birth weight baby as low-stress smokers, the researchers said in a UC Berkeley news release.
Babies who are small for their gestational age can have serious health problems.
The effects of air pollution on pregnant women were also magnified by stress, the researchers said.
The researchers did not examine how stress and chemicals might interact to increase the risk of having a low birth weight baby. Nor can the study actually prove stress was the causative factor.
The study was published July 12 in the journal PLOS ONE.
The March of Dimes has more on low birth weight.