Tobacco use during pregnancy detrimental to offspring’s neurocognitive development

Tobacco use among pregnant women appears to contribute to long-term language and memory impairments in children, according to a study.

The study included 11,448 children between 9 and 10 years of age (wave 1; mean age 9.9 years, 52.3 percent boys, 52.8 percent White). These children underwent a 2-year follow-up when they were between 11 and 12 years of age (wave 2).

Neurocognition was measured using the National Institutes of Health (NIH) Toolbox Cognition Battery. In addition, brain structures in defined regions were assessed using structural magnetic resonance imaging (sMRI).

Of the children, 1,607 were born to mothers who used tobacco during pregnancy (exposed group). In the NIH Toolbox Cognition Battery, this group had poorer performance on the oral reading recognition (mean B, −1.2; p<0.001), picture sequence memory (mean B, −2.3; p<0.001), and picture vocabulary (mean B, −1.2; p<0.001) tests and had a lower crystallized cognition composite score (mean B, −1.3; p<0.001) at wave 1 compared with the group of children whose mothers did not use tobacco during pregnancy (control). Results at wave 2 followed a similar pattern.

SMRI data showed that the exposed group, compared with the control group, had substantially smaller cortical areas in precentral (mean B, −104.2 mm²; p=0.001), inferior parietal (mean B, −153.9 mm²; p<0.001), and entorhinal (mean B, −25.1 mm²; p<0.001) regions.

The exposed group also had markedly lower cortical volumes in precentral (mean B, −474.4 mm³; p<0.001), inferior parietal (mean B, −523.7 mm³; p<0.001), entorhinal (mean B, −94.1 mm³; p<0.001), and parahippocampal (mean B, −82.6 mm³; p<0.001) regions at wave 1. The observed between-group differences persisted at wave 2.