Tobacco Use in Pregnancy

Abstract

Although 18% to 25% of female smokers in the United States have been reported to quit smoking once they become pregnant, 13% of all women report smoking during the last 3 months of pregnancy. Higher rates are reported among women of lower socioeconomic status, who live below the poverty line, and who have less than 12 years of formal education.1 Cigarettes expose mothers and their fetuses to more than 4000 compounds, including 100 carcinogens and mutagens, resulting in serum carbon monoxide levels 3 times higher in smokers than in nonsmokers and fetal plasma concentrations twice that of their mothers. Like carbon monoxide, nicotine crosses the placenta and is measurable at higher levels in the amniotic fluid and the fetal plasma than in maternal plasma.2 Similarly, secondhand smoke exposure can result in fetal levels of nicotine and cotinine as high as one third that of fetuses exposed to maternal smoking during pregnancy.3 Thus, both maternal smoking during pregnancy and maternal exposure to secondhand smoke represent direct exposures to even higher levels of those compounds in the developing fetus. Ideally, no woman would smoke during pregnancy. Given the observations presented above, there is an apparent gap between ideal and existing patient care. This article addresses the existing gap by focusing on 3 primary areas. First, it reviews the effects of smoking on both pregnancy outcomes and childhood/adult health outcomes of the exposed fetus— a critical component of the obstetrician’s ability to provide evidence-based patient education and counseling. Second, it describes and recommends an approach to physicianbased interventions that have been demonstrated to have efficacy in promoting smoking cessation in the pregnant population. Finally, it reviews evidence regarding the safety and efficacy of nicotine replacement therapy (NRT) to allow for informed clinical decision making regarding its use on an individual basis.