Study: BPA Exposure in Womb Linked to Kids' Behavior Problems
But Researchers Caution Study Only Shows Association, Not Cause and Effect
Oct. 24, 2011 -- Preschoolers exposed to higher levels of bisphenol A (BPA) in the womb may have more anxiety and depression and have worse self-control than those exposed to lower levels of the chemical before birth, a new study shows.
The chemical is found in a wide array of consumer products, including plastic bottles, food packaging, dental sealants, and the heat-activated paper that's used to print cash register receipts.
A spokesman for an industry group says the new study had flaws in its design, and that other studies have found BPA to be safe.
The chemical structure of BPA is similar to the hormone estrogen. That raises concerns that constant exposure could have biological effects, particularly for developing babies and young children.
Studies of animals exposed to BPA have found changes in the brain, behavior, and abnormal development of reproductive organs. So far, there has been less evidence of health effects in humans.
The new study is published in Pediatrics. It is one of the first to show that BPA exposure in the womb may be linked to behavioral effects in young children.
Researchers caution though that their study was only able to show associations between BPA and behavior. It did not prove cause and effect.
In an emailed statement, Steven G. Hentges, PhD, of the American Chemistry Council's Polycarbonate/BPA Global Group, says it is unlikely that BPA caused the behavioral effects documented in the study. "The study released in Pediatrics has significant shortcomings in study design and the conclusions are of unknown relevance to public health. Furthermore, regulators from Europe to Japan to the US have recently reviewed hundreds of studies on BPA and repeatedly supported the continued safe use of BPA."
Childhood Behavior and BPA
For the study, researchers followed 244 mothers and their babies from pregnancy through age 3. They measured BPA levels in three urine samples taken from pregnant women and three samples collected from their kids at yearly study visits.
After the children's third birthday, researchers gave parents two well-regarded psychological tests to evaluate their child's behavior and their capacity for self-control. Parents were not given information about their BPA levels before they rated their child's behavior.
While there was no association between the BPA in a child's urine and their behavior, the researchers found that moms who had higher levels of BPA in their urine during pregnancy also had 3-year-olds with more anxiety, depression, and hyperactivity.
Anxiety and depression associations were almost twice as large for girls as they were for boys.
Girls had higher scores on measures of hyperactivity while boys had lower scores for hyperactive behavior.
That was true even after researchers took into account a host of things that are known to influence a child's behavioral development, like mom's IQ and education, breastfeeding, household income, maternal depression, and exposure to tobacco smoke.