Smoking during pregnancy increases the risk of schizophrenia in newborns

Increased risk of schizophrenia in children due to prenatal nicotine exposure
It has been known for some time that mothers who smoke during pregnancy harm the health of their unborn child. Researchers now found that children of mothers who smoked during pregnancy were more likely to develop mental disorders later in life. Affected children have an increased risk of developing schizophrenia by up to 38 percent.

Smoking during pregnancy harms the baby. Scientists at the Columbia University's Mailman School of Public Health, the Columbia University Medical Center (CUMC) and the New York State Psychiatric Institute have now discovered in a study in collaboration with Finnish researchers that higher levels of maternal nicotine in the blood can be increased by up to 38 percent increased likelihood of schizophrenia was associated with the offspring. The physicians published the results of their study in the journal "The American Journal of Psychiatry".

Pregnant women should not smoke, so they protect their unborn children from serious illnesses of body and mind. (Image: wong yu liang / fotolia.com)

Researchers find cotinine biomarkers in children of smoking mothers
Using data from a large national Finnish birth cohort of pregnant women, the research team analyzed nearly 1,000 cases of schizophrenia. In addition, Finnish children's controls were found to have elevated levels of the biomarker cotinine. All of the examine children were born between 1983 and 1998, the experts explain. Cotinine is a degradation product of nicotine and is also found in passive smokers in blood and urine as an N-glucuronide conjugate. The findings of the new study also looked at factors such as the parents' psychiatric history, maternal age and socioeconomic status, explain the physicians.

Smoking during pregnancy increases the risk of long-term changes in perception
This is the first biomarker-based study that shows a link between fetal nicotine exposure and schizophrenia, explains author Professor Alan Brown of Columbia University's Mailman School of Public Health. Nicotine passes through the placenta in the fetal circulation and specifically targets the fetal development of the brain. This process can lead to long-term changes in perception and may also contribute to other disorders of development, the professor adds. Long-term changes in cognition and development of nerve anomalies can then result.

Schizophrenia is certainly not the only problem that can be triggered by smoking during pregnancy. Smoking during pregnancy can also contribute to lower birth weight and different attention difficulties, say the scientists. In addition, in a previous study, Professor Brown and colleagues found that there was a link between smoking during pregnancy and increased risk of bipolar disorder.

Further research should determine triggering biological factors
The current results clearly show the potentially debilitating effects of smoking during pregnancy, say the experts. However, all of these effects of smoking on our children are largely preventable, explains Professor Brown. Future studies on maternal smoking and other genetic and epigenetic factors should, in his view, allow identification of the responsible biological mechanisms. In addition, it is also of interest to consider maternal nicotine exposure in relation to other psychiatric disorders such as autism, adds the author. (As)