Prenatal Exposure to Smoking Has Lasting Effects

Expectant mothers are warned to avoid smoking during pregnancy as it can lead to premature birth and a higher rate of stillbirth. In addition, smoking during pregnancy can result in children who have birth defects or respiratory problems. A study provided evidence that nicotine exposure to the fetus can lead to alterations in the child’s reward processing during adolescence.

Altered reward processing is known to produce risk-taking behaviors in teens like experimentation with illegal substances or dangerous joyriding in a car. Teens engage in these types of behaviors because of the pleasure response in the brain.

The findings, published in JAMA Psychiatry, add support to expert assertions that repeated prenatal pleasure center stimulation has lasting impacts on how the child responds to future rewards.

The study included 177 individuals ages 13-15 who were exposed to prenatal cigarette use. When compared with teens who had not been exposed to nicotine in the womb, these teens were found to be more impulsive and more likely to be excited when presented with opportunities to try new experiences, including drug experimentation.

Among the teens involved in the study that were exposed to prenatal nicotine, five percent had used cigarettes in the previous 30 days, eight percent exhibited risk factors for alcohol abuse and 45 percent had tried a cigarette. Of teens that had not been exposed to nicotine during fetal development only 32 percent had tried a cigarette.

The study participants were told to press a button when an image popped up on a screen about potential reward if they pressed the button quickly enough. The prenatal smoking exposure teens became excited and impulsive when presented with a potential reward and reacted with strong negativity when they did not succeed.

The teens also performed in a way that indicated that there was limited understanding of the connection between the visual stimuli and the expected motor response. The exposed teens largely pushed the button too late, eliminating the possibility of the reward. As the teens went on with the exercise, the anticipation of a reward improved reaction times, but did not improve accuracy rates.

The researchers believe that the results can be explained by altered brain structures that lower the capabilities of neurotransmitters that lead to pleasure responses in the brain. This reduces natural pleasure reactions, which may lead the child to seek out ways to increase pleasure, thus setting the stage for teen drug experimentation and addiction.

The findings highlight the importance of anti-smoking awareness among expectant mothers. While this behavior has long been known to increase the chances of low birth weight and other pregnancy complications, this study provides evidence that the effects are lasting and severe.

Expectant mothers should talk with their obstetrician about smoking cessation help. A physician can provide information and then support and encourage the mother as she seeks to provide a healthy start for her baby.