Behavioral and biochemical effects of gradual reductions in cigarette yields in pregnant and nonpregnant smokers

Abstract

Smoking-related risks have been well-documented for both the smoker and the pregnant smoker's unborn child, but the risks associated with low tar/nicotine cigarette smoking are still controversial. The present study examined some of the behavioral and biochemical effects of gradual reductions in tar and nicotine yields in six pregnant and six nonpregnant smokers. Over four sessions spanning a 6-week period, smokers switched to cigarette brands progressively lower in tar and nictotine. Examination of the topographical variables assessed both during (cigarette frequency, puff frequency, and cigarette duration) and between sessions (daily cigarette rate and nicotine intake) revealed significant decreases in both pregnant and nonpregnant smokers' cigarette duration and nicotine intake. Also observed were significantly lower and less variable carboxyhemoglobin (COHb) levels among the pregnant smokers when they smoked the lowest tar and nicotine brands. However, even the pregnant smokers' lower mean COHb levels did not drop below the 3% minimal cardiovascular risk level. The pregnant smokers also tended to have lower and less variable salivary thiocyanate (SCN) levels, but these differences were nonsignificant. The results were discussed in terms of implications for controlled smoking treatment programs for pregnant smokers.