When Mom Smokes, Brains Don't Develop

Smoking while pregnant can impair the childs brain development

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Data keeps rolling in about the dangers to an unborn baby if the mother smokes. A recent study suggests that brain damage and developmental problems are more likely for the babies of smoking mothers.

New data shows that prenatal smoking causes as much as a 40 percent increase in the probability of developmental issues when the babies are between 3 and 24 months. Children from poor families were most impacted.

"This is a no brainer, quit smoking."

George Wehby, a professor at the University of Iowa's College of Public Health and this study's lead author reports that poor mothers often smoke a great deal more during pregnancy, which in turn affects their unborn child more. However, the number of cigarettes doesn't fully explain the discrepancy.

Also, a woman of a higher socioeconomic class may have healthier behaviors that help offset the bad effects of smoking, Wehby reports.

Study subjects were recruited from health clinics in Central and South America. Almost 1,600 children were included in this study. Mothers were questioned about their smoking habits, and babies received neurological screening.

Nearly 11 percent of these mothers had smoked during pregnancy.

Researchers concede that mothers who smoke during pregnancy are also more likely to participate in other activities while pregnant that could harm their child, including drinking. That said, previous studies that don't take other hazardous activities into account should be overestimating the effects of cigarettes.

However, women with high-risk pregnancies are less inclined to smoke and their babies are still at-risk for reduced neurodevelopment.

This study's researchers used a statistical technique that takes these two biases into account. Their consideration of geographical differences in smoking as it related to different pricing of cigarettes was felt to ameliorate these differences. If women were smoking less due to economic issues, their other risky behaviors were probably less.

Researchers using this control mechanism were able to zero in on the smoking effect specifically.

After these controls were set in place, the smoking effect on the babies was found to be stronger than without them. This suggests previous studies were underestimating the actual effects of smoking on the babies.

In spite of mounting evidence of the dangers of prenatal smoking, rates are quite high for women in the United States. According to the Center for Disease Control and Prevention, 12 percent of women smoked during pregnancy in 2005.

This study's findings are published in the online version of Journal of Human Capital.

Reviewed by: 
Review Date: 
August 22, 2011
Last Updated:
August 31, 2011