Smoking during pregnancy: Research reveals link to impaired brain growth

Prenatal nicotine exposure impairs the growth of the fetal visual cortex, according to research conducted by Tomasz Paus and colleagues at the Saint-Justine center in Montreal. The findings suggest that nicotine specifically targets the mechanisms responsible for developing the visual system rather than affecting the brain uniformly. The development of the visual cortex relies on spontaneous electrical waves generated by the retina. These signals travel to the brain to stimulate the proliferation of progenitor cells. Nicotine disrupts this transmission, which inhibits tissue development. Researchers first analyzed data from 27,000 adults via a British biobank. MRI scans revealed that individuals whose mothers smoked during pregnancy had a smaller overall cortical area, with the most significant reduction occurring in the visual cortex.