Smoking in pregnancy damages developing arteries

Women who smoke during pregnancy may cause permanent damage to their child's blood vessels that can be detected in young adulthood and which may increase the child's risk of cardiovascular disease, suggests research reported today at an American Heart Association meeting in Orlando.

"Women need to stop smoking, especially in pregnancy, not only for their own health, but for their unborn child," study leader Dr. Cuno S. Uiterwaal of University Medical Center Utrecht in the Netherlands said in an AHA statement.

There is growing interest in the "early life origins of chronic disease in later life," fueled in part by the finding that low birth weight is associated with a higher rate of cardiovascular disease, Uiterwaal told Reuters Health.

Because exposure to tobacco smoke in pregnancy is one of the important factors leading to low birth weight, the Dutch researchers attempted to find out if smoking during pregnancy also leads to higher risk of cardiovascular disease.

In review of the medical files of 732 people born between 1970 and 1973 who had their vascular health checked in between 1999 and 2000, the researchers found that adult children of the 215 mothers who smoked during pregnancy had much thicker walls of the two major arteries in the neck, the carotid arteries, than did adult children of mothers who did not smoke while pregnant.

Increased thickness of the carotid arteries signals increased risk for cardiovascular disease, including stroke.

If both parents smoked during pregnancy, the children, as young adults, had thicker carotid arteries than their counterparts with either one smoking parent or tobacco-free parents.

"Our findings suggest that both smoking by mothers themselves in pregnancy and exposure to passive smoking are important," Uiterwaal said in a statement. "More exposure leads to more vascular damage in the offspring."

The positive associations found in the study were "seemingly independent of other risk factors for cardiovascular disease, including current smoking of the parents or the young adults themselves," Uiterwaal noted.

It's possible, Uiterwaal said that chemicals in tobacco smoke travel through the placenta and directly damage the heart and vascular system of the developing fetus. "The damage appears to be permanent."