According to a new study, published online on December 26 (and also the January 2012 print edition) in the journal Pediatrics, women who smoke during pregnancy may cause vascular damage to their child, which can become apparent at five years of age. In addition, if their partner is a smoke, the risk is increased.
“Smoking during pregnancy has been related to thicker carotid intima media thickness in young adults, and this was also shown in neonates,” wrote Caroline C. Geerts, MD and colleagues from the Julius Center for Health Sciences and Primary Care and University Medical Center Utrecht in the Netherlands and colleagues. “The relation between smoke exposure in early life, the prenatal period in particular, and the vascular development of young children is largely unknown.”
To evaluate the association between parental smoking during pregnancy and subsequent vascular characteristics in their children, the investigators evaluated data from the birth cohort enrolled in the Wheezing Illnesses Study Leidsche Rijn (WHISTLER)-Cardio study. At five years of age, 259 participants underwent ultrasonographic measurement of carotid artery intima-media thickness (CIMT) and arterial wall distensibility. In addition, parental smoking data were also updated.
After adjustment for the child’s age and sex, maternal age, and breast-feeding, children of mothers who had smoked throughout pregnancy were found to have more vascular damage than children of mothers who did not smoke during pregnancy. Children of mothers, who smoked after pregnancy but not during pregnancy, did not suffer from these adverse effects on CIMT and distensibility. If both parents smoked during pregnancy, the associations were even stronger than with only maternal smoking.
The authors noted, “This study is the first to show that the effect of smoking during pregnancy on the vasculature of children is visible at the age of 5 years… Pregnancy appears to be the critical period for this damage to occur.”
The authors noted that limitations of their study included slightly different profiles in participants than in nonparticipants, lack of nicotine measurements at birth, and reliance on parental self-report of smoking. They concluded, “In view of the early origins of cardiovascular disease, preventive measures against smoking should be specifically directed at the gestational period.”
Take Home Message: One out of five women in Los Angeles County smoke. Some quit when they become pregnant; however, others do not. This study is one more that points to the harmful effects of smoking on the unborn child. It also notes the increased harm from residing with a partner who smokes.