Study: BPA Exposure in Womb Linked to Kids' Behavior Problems
But Researchers Caution Study Only Shows Association, Not Cause and Effect
Childhood Behavior and BPA continued...
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.
"The results suggest that these gestational exposures, or the mother's exposure, are more important than the childhood exposures," says researcher Joe Braun, MSPH, PhD, research fellow in the department of environmental health at the Harvard School of Public Health.
Braun says girls may be more susceptible to the effects of BPA during their development than boys. He's not entirely sure why, but he has a theory.
"We know that sex steroids are important in the development of masculine and feminine behaviors, and it's possible that BPA is acting like a weak estrogen," Braun says.
"In rodents, estrogen actually masculinizes the brain," he says, which could explain the sex differences they saw in hyperactivity. Hyperactivity tends to be more common in boys than girls.
"It's definitely a study that's worth paying attention to," says Amir Miodovnik, MD, an attending pediatrician at the Mount Sinai School of Medicine in New York City. "But you can't take away from it that a child exposed to BPA problems in the womb is going to have behavioral problems. It's not clear-cut like that."
Miodovnik has also studied childhood exposure to BPA and its associations with behavior, but he was not involved in the current research.
"It's important in terms of corroborating some of the animal studies that have found effects. And there are many animal studies that have found effects at low levels. And here we're finding effects at levels that are found in the normal population."