Smoking during pregnancy linked to behavioral problems in children

November 3, 2009 by Shawn Douglas
Filed under: Baby Health, News, Pregnancy

Smoking during pregnancy may significantly increase the risk of behavioral problems in a mother’s child later in life.

New research set to be published in the Journal of Epidemiology and Community Health suggests that mothers who smoke while pregnant are essentially toying with the brain chemistry of their future children.

“There are 4000 toxic substances in cigarette smoke, and many of these will pass into the brain of the fetus, and it is possible that they could have an effect on how the brain chemistry works,” said Professor Alan Maryon-Davis, president of the Faculty of Public Health, to the BBC.

The research involved more than 14,000 pairs of mothers and their children, all participants in the Millennium Cohort Study, a study that focused on children born in the U.K. between 2000 and 2001.

First, mothers were put into categories based upon the amount of cigarettes they smoked during pregnancy. Then, using a validated questionnaire called Strengths and Difficulties, mothers were asked to grade their children’s level of hyperactivity, type of temperament, frequency of fights, and ease of distraction. Taking into account factors that might influence the results, including socioeconomic status, mother’s age, and level of education, the researchers began analyzing the data.

It was found that nearly one in ten women smoked heavily during pregnancy, 12.5 percent smoked lightly during pregnancy, and 12.4 percent said they stopped smoking while pregnant.

Boys of mothers who smoked heavily while pregnant were almost twice as likely to have behavioral problems, while boys of mothers who smoked lightly while pregnant had an 80 percent increased likelihood of having an attention deficit disorder.

Researchers found a significant increase in likelihood that those girls of mothers who smoked lightly or heavily had conduct issues.

“Smoking during pregnancy may damage the developing structure and function of the fetal brain, which has already been shown to be the case in animals”, said the authors.

“The fetal development of boys may also be more sensitive to this kind of chemical assault, which might explain why boys are more likely to have behavioral problems than girls.”