DESCRIPTION: (Applicant's Abstract) Cigarette smoking is the leading preventable cause of morbidity and mortality in the United States today. Cigarette smoking during pregnancy poses a serious but preventable health risk to both the pregnant woman and the fetus. While many pregnant women quit smoking on their own or with the help of behavioral smoking cessation interventions, there are a substantial number of pregnant women who are unable to quit smoking. These women continue to be at risk for adverse pregnancy outcomes associated with cigarette use. Nicotine replacement therapy (nicotine patch) has been shown to increase smoking cessation rates in a number of clinical trials. Although the nicotine patch is successfully used to aid smokers to quit, its' use has not been tested in treating nicotine addiction in pregnant women. A large beneficial public health outcome is achievable if nicotine patch use results in increased smoking cessation rates in pregnant women who have failed to quit smoking after a behavioral smoking cessation program. We hypothesize that nicotine patch use will result in increased initial and long term rates of smoking cessation as compared to placebo patch use in pregnant women who continue to smoke after completing a behavioral smoking cessation intervention. Therefore, we propose to test this hypothesis in a two-armed randomized clinical trial of the effect of the 16 hour nicotine patch (Nicotrol) as compared to a placebo patch on smoking cessation rates in pregnant women who have failed to quit smoking with a behavioral smoking cessation intervention. Our primary endpoint assessment is the difference in smoking cessation rates as validated by biochemical measures between the treatment group (nicotine patch) and the control group (placebo patch). Our randomized clinical trial will provide a rigorous test of the efficacy of nicotine patch use in treating nicotine addiction in pregnant women smokers.