While the study results indicate that prenatal exposure to second-hand smoke can be harmful to the unborn child regardless of socioeconomic conditions, the data also suggest that lower-income children may be less able to compensate for these effects over the next few years of life. The study will appear in the March 2004 issue of the journal Neurotoxicology and Teratology.
The study, conducted by researchers at the Columbia Center for Children's Environmental Health, part of the Mailman School of Public Health at Columbia University, found that children whose mothers are exposed during pregnancy to second-hand smoke have reduced scores on tests of cognitive development at age two, when compared to children from smoke-free homes.
The reduction amounts to almost five developmental quotient points out of an average score of 100. In addition, the children exposed to second-hand smoke during pregnancy are approximately twice as likely to have developmental scores below 80, which is indicative of developmental delay.
These differences are magnified for children whose mothers lived in inadequate housing or had insufficient food or clothing during pregnancy. The combined effect results in a developmental deficit of about seven points in tests of cognitive performance.
While the influence of material hardship on the association between second-hand smoke and cognitive development was measured during the postnatal period, the test results show that the subjects' postnatal e
Contact: John Peterson
NIH/National Institute of Environmental Health Sciences