Secondhand smoke may affect brain of fetus

Pregnant women who are chronically exposed to secondhand smoke may have children who are at greater risk of problems related to attention and emotion, University of Washington researchers believe.

In a study released Wednesday, scientists found that children who have such psychological problems have a higher frequency of them -- or more severe troubles -- if their mothers were regularly exposed to tobacco smoke while pregnant.

Those troubles include Attention Deficit Hyperactivity Disorder (ADHD), aggressive behavior, defiance and a behavior pattern called conduct disorder, which can include truancy, fighting, failing in school, substance abuse, theft and property destruction.

"Parents should be really aware of the [fetal] brain development going on during pregnancy," said psychologist Lisa Gatzke-Kopp, lead investigator of the study, which was reported in the current issue of the journal Child Psychiatry and Human Development. "It's a very sensitive period of time."

Gatzke-Kopp said scientists believe that nicotine in tobacco smoke affects fetal brain development, including areas responsible for emotions and feelings.

In the study, Gatzke-Kopp and Theodore Beauchaine, a UW associate professor of psychology, compared 171 children, mainly boys, who were divided into three groups:

• Children of 96 mothers who did not smoke during pregnancy.

• Children of 21 mothers who smoked during the final six months of pregnancy.

• The children of 16 mothers who didn't smoke but were exposed to secondhand smoke.

Mothers exposed to nicotine -- the smoking mothers and the secondhand smoke mothers -- generally had children with more severe problems with attention or more severe emotional and behavioral problems than the children of nonsmokers, said Gatze-Kopp.

She said the findings could extend to all children whose mothers were exposed to tobacco smoke during pregnancy.

Gatze-Kopp said the data for the study were taken from a larger study of the relationship between depression and conduct disorder. She granted that the smoking study is as a small sample and needs additional research.

Previous research, cited in a 2006 U.S. Surgeon General's report, found that secondhand smoke may increase the risk of miscarriages and instances of babies with low birth weights.

Gatze-Kopp said pregnant women should avoid any chronic exposure to secondhand smoke.

"Mothers should know: 'If it's not safe for me, it's not safe for my baby,' " she said.

Warren King: 206-464-2247 or wking@seattletimes.com

Information in this article, originally published June 28, 2007, was corrected July 2, 2007. A University of Washington study suggested that pregnant women who are chronically exposed to tobacco smoke may have children at greater risk of attention and emotional problems than the children of mothers who are not exposed to the smoke. The original version of the story about the study contained an editing error in some editions that stated the children born to pregnant women chronically exposed to tobacco smoke had a higher risk of the problems. The name of psychologist Lisa Gatzke-Kopp, a University of Washington scientist, was misspelled in this article.