FRIDAY, Oct. 30 (HealthDay News) -- Relying on women to self-report whether they smoke results in many pregnant smokers going undetected each year, according to a study published online Oct. 29 in BMJ.

Deborah Shipton, Ph.D., of the Medical Research Council Social and Public Health Sciences Unit in Glasgow, U.K., and colleagues studied a random sample of 3,475 women in the west of Scotland who underwent second trimester prenatal screening over a one-year period. They validated smoking status with cotinine measurement by maternal area deprivation category.

The researchers found that reliance on women's self-reported smoking status underestimated true smoking prevalence by 25 percent. They projected that more than 2,400 pregnant smokers go undetected in Scotland every year. Thirty-nine percent of pregnant smokers in the least deprived areas did not report smoking, compared to 22 percent of pregnant smokers in the most deprived areas. However, because smoking is far more common in the most deprived areas, it would be expected that there are twice as many undetected pregnant smokers in the most deprived areas as the least deprived.

"Reliance on self-reporting to measure smoking during pregnancy significantly underestimates the number of pregnant smokers in Scotland, with more than 2400 unrecognized pregnant smokers a year who will not be offered smoking cessation services. Overall, these figures call for more accurate methods of identifying pregnant smokers, especially when such data are used to inform policy and provide patient care," the authors conclude.

Abstract
Full Text