Pregnant women who smoke are ashamed to admit it. That’s the conclusion of a study using data from a recent National Health and Nutrition Examination Survey, which was conducted from 1999 to 2006. According to the results, 23 percent of pregnant women claimed they don’t smoke even though they had high blood levels of cotinine, a tobacco metabolite and biomarker of tobacco exposure. Secondhand smoke may also increase cotinine levels, but since pregnant women metabolize the chemical more quickly than nonpregnant women, the rate of smoking during pregnancy may actually have been underestimated, researchers of the study published in The American Journal of Epidemiology say.
Unlike ingesting alcohol during pregnancy, which when consumed in modest amounts has weak evidence for adverse fetal effects, smoking is known to be very dangerous to the developing baby. “Therefore,” says ACSH’s Dr. Gilbert Ross, “it’s no surprise that when asked about their smoking habits, these women downplay them. When questioned by their doctor, many of them might even explain away the high cotinine levels by saying they were were exposed to secondhand smoke at a party, but doctors should consistently remind pregnant women to not smoke and to also avoid social gatherings where many people are smoking.”
Whether still in the womb or already a toddler, parental smoking habits can have a negative health impact on children. In a 2007-2008 study of 4,236 five-year old German children, those with one or both parents who smoked had an increased likelihood that their blood pressure reading would fall into the top 15 percent of the total sample.
Though being overweight and having a hypertensive parent were more strongly associated with high blood pressure in children, lead study author Dr. Giacomo D. Simonetti says that smoking is most likely the easiest risk to modify. Dr. Simonetti also says that high childhood blood pressure persists into adulthood when it becomes a major contributor to heart disease risk.
“Convincing parents who smoke to quit by advising them of the implications for their children may be more effective than detailing the risks to themselves,” adds Dr. Ross.