The study involved 732 young adults, born between 1970 and 1973, who were evaluated at around 30 years of age. Compared with young adults of mothers who did not smoke during pregnancy, young adults of mothers who did light up during pregnancy had much thicker walls of the carotid arteries in the neck that supply blood to the brain.

Even if the mothers did not smoke during pregnancy, having a father who smoked during gestation was also associated with thicker neck or "carotid" arteries. The association was strongest when both parents smoked during pregnancy.

Dr. Cuno S. P. M. Uiterwaal, from University Medical Center Utrecht in The Netherlands, and colleagues also found that young adults of mothers who smoked were more likely to smoke themselves, and these subjects had the greatest increase in carotid artery thickness compared with nonsmokers who were not exposed in the womb to tobacco.

"The interaction between participant’s current smoking behavior and maternal smoking during pregnancy could indicate that if the cardiovascular system is exposed to tobacco smoke in utero, the vessels are more vulnerable to tobacco smoke later in life."

On the other hand, current smoking by women who abstained during pregnancy had no effect on the thickness of their children’s neck arteries.

"Our findings were largely independent of other cardiovascular disease risk factors," the Uiterwaal and colleagues point out, lending plausibility to the notion of deleterious vascular effects from gestational exposure to tobacco smoke. – Reuters