Maternal smoking may increase risk for neuropsychiatric disorders in kids: Study

Zee Media Bureau

New York: Pregnant women should not smoke as it is not good for the baby and also increases the risk of developing neuropsychiatric disorders in children which is associated with behavioural problems. It also give rise to an increased risk of the development of disease risks later in the child's life.

Maternal smoking during pregnancy also increased the risk for Tourette syndrome and other chronic tic disorders in kids. It not only harm the unborn child but the mother as well.

It is said that tobacco smoking and pregnancy are related to many effects on health and reproduction.

Smoking during pregnancy also causes reduced lung function in infants, and may also cause an increase in the number of lower respiratory tract illnesses, including wheezing, during infancy.

Infants who are born to women who have smoked during pregnancy have weakened innate immune defences, more prone to respiratory infections and develop their acquired immune system more slowly than infants of non-smoking mothers.

The study was conducted and researchers said that the link seems especially strong for complex presentations of the Tourette syndrome which is a nervous system disorder involving repetitive movements or unwanted sounds -- in which two or more psychiatric disorders like chronic tic disorders and pediatric obsessive-compulsive disorder (OCD) are present.

Researchers found that heavy maternal smoking (10 or more cigarettes a day) during pregnancy caused a 66 per cent increase in the risk for chronic tic disorders in the child.

Dorothy Grice, Professor at the Icahn School of Medicine at Mount Sinai, New York, US said, "Our study not only shows an important role for maternal prenatal smoking in risk for both simple and complex chronic tic disorders in children, but it also suggests that smoking may be exerting some of its effects through subtle changes in brain development that might occur as a result of foetal exposure to nicotine".

Heavy smoking when pregnant has been associated with a two to three-fold increased risk of several behavioural manifestations in children, including neuropsychiatric difficulties such as chronic tic disorders and attention-deficit/hyperactivity disorder (ADHD).

Mothers who smoke during pregnancy have high chance of having a psychiatric disorder, so it may be that the risk for psychiatric disorders is transferred from parent to child by genetic factors or environmental factors that are not directly related to smoking.

Maternal smoking can also lead to lower birth weight and premature delivery in children and can become a risk factor for subsequent behavioural problems in the child.

Furthermore, parental smoking is associated with lower socio-economic status and higher rates of alcohol and substance use, and these factors are also linked to behavioural changes in children.

Developing a clear understanding of both the risks for behavioral problems in children and then the mechanisms by which these risk factors operate is a complex undertaking that benefits from very large epidemiological samples and ongoing, rather than retrospective, data collection.

"Identifying environmental causes for chronic tic disorders and related psychiatric conditions is important because if we know specific risk factors, we can develop more effective strategies for prevention," said Grice added.

"The next step is to understand how these environmental factors exert their effects on risk, as this will provide a window into the biological mechanisms that underlie these conditions. As we learn more about the neurobiological pathways that underlie a specific disorder, we will be better positioned to develop more specific and targeted treatments. Our study not only shows an important role for maternal prenatal smoking in risk for both simple and complex chronic tic disorders in children, but it also suggests that smoking may be exerting some of its effects through subtle changes in brain development that might occur as a result of fetal exposure to nicotine."

Researchers observed a 66% increased risk for chronic tic disorders in the child said that heavy smoking is associated with a 2- to 3-fold increased risk of chronic tic disorders occurring with other psychiatric diagnoses in the child ("complex" chronic tic disorders), such as ADHD.

For the study, the team looked at data from 73,073 pregnancies, focusing on maternal smoking (including light versus heavy smoking) and children presenting with chronic tic disorders or pediatric OCD.

The team also adjusted for factors associated with maternal smoking, including maternal age, presence of maternal psychiatric disorders, socioeconomic status, consumption of beer, wine, spirits, coffee, and hashish during pregnancy, gestational age and birth weight, as well as partner smoking.

Further study on how smoking and nicotine exposure alters brain development may offer insight into the brain changes that lead to these outcomes. Educational and treatment programs will support mothers to reduce and eliminate smoking during pregnancy will have beneficial effects for both the mother and the child.

The findings was published in the September 2016 issue of the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP).

(With Agency inputs)