This Is Your Child's Brain on Smoking

Smoking during pregnancy linked to different part of brain in memory tasks for children

(RxWiki News) There are 101 reasons not to smoke while you're pregnant. But here is reason #102: there's some evidence it might change the way your child's brain works later on.

A very small study has recently found that children exposed to tobacco smoke before birth use a different part of the brain to work out problems than unexposed children.

"Pregnant? Stop smoking!"

The study, led by David S. Bennett, PhD, of the Drexel University College of Medicine in Philadelphia, aimed to find out whether prenatal exposure to tobacco smoke was linked to memory problems in children.

Because it's a very small study, the findings are limited. They may not apply to all children whose mothers smoke during pregnancy.

The participants included 7 children who had been exposed to tobacco smoke while in the womb and 11 children who were not exposed to smoking before birth. All the children were 12 years old.

The children all performed a task that required them to use their short-term memory while they were being assessed with a functional magnetic resonance imaging (fMRI) scan.

An fMRI is a way to view parts of the body such as the brain to see which areas are activated during a task.

The researchers found that the children who had been exposed to smoking before birth had more activity in parts of the brain called the "inferior parietal regions." The unexposed children had more activity in the "inferior frontal regions."

These are two different regions of the brain. The activity occurred in these children's brains when they correctly completed the task they were given.

The researchers state that these results imply that children exposed to prenatal tobacco smoke use a different part of the brain and possibly a different way of thinking to get a correct answer compared to children unexposed to tobacco.

The researchers adjusted their results to account for whether the children had been exposed to alcohol before birth and whether they had experienced medical problems as newborns.

The researchers also controlled for the children's gender and other environmental risks they may have been exposed to.

It's not clear what it means that the children use different areas of the brain, but past research has shown that children exposed to tobacco smoke before birth "exhibit higher rates of learning and emotional-behavioral problems related to worse working memory performance," the authors write.

If the worse performance is related to the findings in this study that exposed and unexposed children use different parts of the brain, this may be an area to address in improving the short-term memory of the children exposed to tobacco.

"Such improvements in working memory may lead to improved academic and behavioral performance for children," the authors write.

The study was published July 21 in the journal Brain Imaging Behavior. The research was funded by grants from the Pennsylvania Department of Health and the National Institute on Drug Abuse. The authors declared no conflicts of interest.

Review Date: 
September 24, 2012