Though it is no secret that smoking is bad and pregnant women should avoid smoking for the health of the unborn child, a new study identifies impacts on behavior for children exposed to maternal smoking.

The study, which was published in JAMA Psychiatry, found a statistically significant correlation between exposure to maternal smoking and conduct problems between the ages of four and 10.  Researchers also accounted for children reared by their biological mothers and children reared by adoptive parents, but still found a significant relationship.

Using data from three earlier studies, which took place in the U.S., the U.K. and New Zealand, the researchers combined the information for a larger analysis.  These studies asked mothers whether or not they smoke cigarettes during pregnancy.  Then, researchers collected information from the parents and teachers about the conduct problems of the children.  For children that were raised by the biological mother, children with exposure to maternal smoking showed a significantly higher level of conduct problems.  For children that were raised by adoptive parents, a significantly higher level of conduct issues persisted.  This demonstrated that the environment did not alter conduct problems correlated with exposure to maternal smoking.

An earlier study, conducted in 1998, looked at the impact of cigarette smoking on a wider array of psychiatric issues.  This research found that maternal smoking during pregnancy increased the prevalence of conduct disorders, major depression, anxiety, and substance abuse in the child.  Some of these effects would be moderated by accounting for family background, child-rearing practices, and parental characteristics.

The March of Dimes identifies some of the key risks of smoking while pregnant.  The woman is more likely to suffer a placental abruption, where the placenta comes partially away from the uterine wall before delivery, stillbirth, vaginal bleeding, or an ectopic pregnancy.  The child is more likely to have birth defects, have low birthweight, and be born prematurely.

Smoking is damaging to the unborn child because of ingredients in cigarettes and the manner in which cigarettes affect necessary bodily functions.  Smoking while pregnant reduces the amount of oxygen available to both the mother and the child.  It increases the likelihood that the child will suffer from a respiratory condition.  Moreover, the child will be exposed to poisons including nicotine and carbon monoxide.  If smoking continues after the child is born, the risks persist.  The child is more likely to develop allergies, asthma, emphysema, heart disease, and lung cancer.  The infant is also at greater risk of passing away from sudden infant death syndrome (SIDS).  There are numerous smoking cessation programs to help pregnant women and others quit smoking, improving their own health and the health of others around them.