Exposure during pregnancy to flame retardant chemicals commonly found in the home is linked to lower birthweight babies, according to a new study led by researchers at the UC Berkeley School of Public Health.
In the study, to appear Tuesday, Aug. 30, in the peer-reviewed publication American Journal of Epidemiology, researchers found that every tenfold increase in levels of PBDEs, or polybrominated diphenyl ethers, in a mother’s blood during pregnancy corresponded to a 115 gram (4.1 ounce) drop in her baby’s birthweight.
Prenatal exposure to a common chemical found in homes has been linked to lighter babies at birth.
“This is the first, large population-based study to link PBDEs with babies’ birth outcomes,” said study lead author Kim Harley, adjunct assistant professor of maternal and child health and associate director of the Center for Environmental Research and Children’s Health (CERCH) at UC Berkeley. “A 115-gram decrease in weight is a fairly significant finding. By way of comparison, consider that smoking during pregnancy is associated with about a 150- to 250-gram decrease in birthweight.”
The researchers are careful to point out that, while the study found a decrease in birthweight overall, very few babies in the study were born weighing less than 2,500 grams (5.5 pounds), the clinical definition of low birthweight. Low birthweight babies are more likely to experience social and cognitive delays in development.
“This was a very healthy population, and we didn’t see many low birthweight babies. What we saw was a shift toward lighter babies among women with higher PBDE exposure rather than a dramatic increase in the number of low birthweight babies,” said Harley. However, she points out that a 115-gram shift could make a big difference for babies already at risk of being low birthweight, including low-income populations with poor access to prenatal care.
This is the latest finding from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) longitudinal study led by Brenda Eskenazi, UC Berkeley professor of epidemiology and of maternal and child health at the School of Public Health. Previous findings from the CHAMACOS study, which examines environmental exposures and reproductive health in an agricultural community, have associated PBDE exposure to reduced fertility and altered thyroid function in women.
The current study examined PBDEs found in the PentaBDE flame retardant mixture. These chemicals are commonly found in foam furniture, baby products and carpet padding. The use of PentaBDE began increasing in the 1970s in response to fire safety standards implemented in California at that time.