Smoking while pregnant affects sons and daughters differently

Sons of mothers who smoked during late pregnancy are more likely to be non-smokers than daughters later in life. This surprising finding, published in Addictive Behaviors, supports growing evidence that gender plays a significant role in tobacco addiction.  

The researchers conducted a retrospective longitudinal analysis of data as part of the United Kingdom's ongoing National Child Development Study that began in 1958.

Subjects were followed from birth into adulthood and numbered 17,400 at the outset and between 10,000 and 12,000 during follow-up periods.

"By no means do these results suggest any benefits to smoking during late pregnancy," cautioned Brad Collins, Ph.D., assistant professor of public health at Temple University and a study co-author.

Rather, the researchers say, these findings highlight areas needing further investigation, including whether there is some sort of protective factor from male hormones that decreases offspring risk of smoking in adulthood and how nicotine affects the genders differently at a molecular level.

"Decades of research definitively show that smoking during pregnancy significantly increases a child's risk for a variety of diseases as well as neuro-cognitive and developmental problems -- for both genders," Collins said.  

"But one important implication of our study is that boys and girls may be affected in different ways by fetal exposure to maternal tobacco, perhaps depending upon when exposure occurs during fetal development."  

Over the past several years, Collins continued, there's been increasing evidence that males and females may start and continue to smoke for different reasons, and respond differently to various quitting programs.

There are several possible reasons for the apparent gender difference in smoking risk based on fetal tobacco exposure. One is that males could be more sensitive and averse to smoking at a cellular level. The hope is that a better understanding of neuronal effects of fetal tobacco exposure will lead to better, more targeted treatments for males and females.     

"Factors that may influence gender differences in fetal response to tobacco exposure may be consistent with factors that predict differential smoking treatment outcomes," Collins said. "Even with state-of-the-art treatments for smoking cessation, women tend to relapse at higher rates than men."  

He believes that researchers must continue to examine potential gender differences in smoking and to design smoking cessation treatments that address relapse risk factors unique to women, such as post-partum depression, menstrual cycle and hormonal changes, and concerns about weight gain.

Future studies should specifically examine gender differences and include examination of biochemical and genetic data, as well as personality traits and peer factors that influence smoking during adolescence to more accurately assess the impact of fetal nicotine exposure on offspring smoking.

Collins is currently studying maternal smoking, child exposure to secondhand smoke, and factors that influence smoking relapse.

- Eryn Jelesiewicz