The health hazards of tobacco have long been common knowledge, as has the fact that pregnant women should refrain from smoking, drinking alcohol, or ingesting any other conceivably toxic substances. But the immune, neurological, respiratory and cardiovascular risks associated with these substances are not the only harmful outcomes that can result from exposure to tobacco. Research has shown that even second-hand smoke can have a significant effect on a child’s behavior.

In the December 2007 issue of the journal Child Psychiatry and Human Development, researchers from the University of Washington pointed toward cigarettes as a predictor of psychological problems like attention deficit/hyperactivity disorder (ADHD), conduct disorders, and anti-social behavior. Among a group of 171 children aged seven through 15, those who went through their developmental stages in a smoke-free environment were considerably less likely to exhibit symptoms of ADHD than those whose mothers either smoked themselves or regularly interacted with smokers at work or at home. Significantly, those exposed to second-hand smoke had a greater risk than those not exposed to smoke at all. These trends proved true even after controlling for factors such as socioeconomic status, alcohol and drug abuse, and birth weight. Animal studies have shown that exposure to nicotine affects brain development in the later stages of pregnancy, at least partially because it deprives the maturing fetus of oxygen.

Despite public health warnings, many women who smoke continue to do so during pregnancy, and even if they manage to quit, their children may still inherit negative conditions and behaviors promoted by regular tobacco use, such as colic in infancy and hyperactivity in childhood. Nicotine replacement products do not negate this problem, as patches and gums often deposit even more nicotine in the system than smoking itself. In addition, many of those who find quitting so difficult have close family members who smoke, including spouses or partners with whom they share close living quarters, and this proximity to tobacco often proves a substantial barrier to overcoming the addiction. Quitting is crucial, however, as prenatal exposure to tobacco can contribute to negative behavioral outcomes for children, and even exposure to second-hand smoke conveys substantial risks.