FRIDAY, March 2, 2007 (HealthDay News) -- Women who smoke during pregnancy can cause permanent damage to their child's circulatory system, which can increase risks for heart disease and stroke later in life, Dutch researchers report.
"The kids of the mothers who smoked when they were pregnant have an increased atherosclerosis [hardening of the arteries] compared with kids whose mothers didn't smoke," said researcher Dr. Michiel L. Bots, an associate professor of clinical epidemiology at the University Medical Center Utrecht. "Pregnancy is a critical period for damage from smoke exposure," he added.
His team's analysis of data from the Netherlands Atherosclerosis Risk in Young Adults study found that people exposed to smoke when their mothers were pregnant had permanent cardiovascular damage that could be detected in young adulthood.
The findings were expected to be presented Friday at the American Heart Association's Annual Conference on Cardiovascular Disease Epidemiology and Prevention in Orlando, Fla.
In addition, smoking during pregnancy can result in compromised intrauterine growth and low birth weight, Bots noted.
In the study, Bots and colleagues collected data on 732 people born between 1970 and 1973.
They found that, at the age of 30, adult children of the 215 mothers who smoked during their pregnancy had thicker walls of the carotid arteries in the neck -- an early sign of atherosclerosis -- compared with adult children whose mothers didn't smoke.
Offspring whose pregnant mothers were exposed to smoke had 13.4 micrometers thicker carotid artery walls by the time they reached young adulthood compared to the offspring of mothers who did not smoke during pregnancy.
Fathers weren't left off the hook, either. If both parents smoked during pregnancy, by 30 years of age, their children had thicker artery walls than people with one smoking parent or parents who did not smoke, the researchers noted.
Moreover, the more the mother smoked, the thicker the carotid artery walls of her offspring, Bots's team found.
"We have confirmed that smoking during pregnancy is not good for your child," Bots said. "It fits with the evidence that these children have higher blood pressures and are more overweight when they are adults, and we have extended that to show they have more atherosclerosis when they are 30."
One expert said the findings support the common wisdom on smoking and heart disease.
"This study seems to extend what we already know about coronary artery disease, that the process starts very early," said Dr. Byron Lee, assistant professor of medicine, University of California, San Francisco.
Already, children have been found to have fatty streaks in their arteries, Lee said. "These fatty streaks are the precursors to more severe arterial narrowing that can lead to angina and heart attacks. This study suggests that artery disease may even start during gestation, giving pregnant women yet another reason to refrain from smoking," he said.
Another expert agreed.
"This is further evidence of the need for women who smoke to quit," said Matt Barry, the director of policy research for the Campaign for Tobacco-Free Kids. "And also for them to avoid secondhand smoke," he added.
People need to be educated about not smoking in their homes, Barry added. "There need to be more programs to help people quit," he said. "In addition, we need to be more aggressive in reaching out to pregnant women and women of childbearing age."
Barry noted that many women do quit when they are pregnant but then start smoking again after delivery. "Seven out of 10 women who quit [during pregnancy] take up smoking again," he said. "Often, smoking during the postpartum environment is as dangerous as the pregnancy itself."
For more information on the perils of smoking during pregnancy, visit the American Pregnancy Association.