The harmful effects of cigarettes have long been known. But it turns out that if a woman smokes during pregnancy, a bad habit can cause various mental disorders in the unborn child.
Yale University molecular biologist Marina Picciotto and her colleagues conducted experiments1 in mice and found that nicotine exposure to the fetus leads to changes in the genes, which ultimately disrupt the formation of brain cells. As a result, the mice, growing up, showed behavior similar to hyperactivity in children. These changes persisted in rodents throughout life.
«High concentration of nicotine in the blood of women increases the risk of developing schizophrenia in a child by 38%»
Another group of American scientists studied how nicotine affects the human fetus and whether it increases the risk of mental disorders in a child in the future. To do this, they used data from a multi-year study of the risks of developing schizophrenia, conducted in Finland. As part of the study, doctors took blood samples from mothers who gave birth between 1983 and 1998. It turned out that a high concentration of nicotine in the blood of women increases the risk of developing schizophrenia in a child in the future by 38%.
Large-scale work was carried out by Norwegian scientists, who analyzed the data of 9000 mothers and children2. Twice during pregnancy, women were asked if they continued to smoke, and if so, how often. And after the birth of children, scientists figured out how they develop at different stages — at 18 months, 36 months and 5 years. It turned out that children whose mothers smoked during pregnancy were more likely to suffer from anxiety and depression. Especially harmful was smoking in the early stages.
Despite warnings, an average of 10% to 20% of smokers are reluctant to quit the habit even after learning they are expecting a baby. In France, where the problem is particularly acute, as an experiment, doctors offer pregnant women who come for examination gift certificates (a total of 300 euros) for giving up cigarettes. The study began recently, and it will be possible to judge the effectiveness of such measures only in a few years.
1 Y. Jung et al. «An epigenetic mechanism mediates developmental nicotine effects on neuronal structure and behavior», Nature Neuroscience, May 2016.
2 S. Niemelä et al. «Prenatal Nicotine Exposure and Risk of Schizophrenia Among Offspring in a National Birth Cohort», American Journal of Psychiatry, May 2016.