Primary Outcome Measures:
- Biochemically validated quit rates [ Time Frame: 6 weeks after treatment, end of pregnancy ] [ Designated as safety issue: No ]
Secondary Outcome Measures:
- tobacco exposure measurements [ Time Frame: 6 weeks after treatment, end of pregnancy ] [ Designated as safety issue: Yes ]
- birth weight [ Time Frame: time of delivery ] [ Designated as safety issue: Yes ]
This proposal will examine the utility of one first-line medication, nicotine gum, as an aid to smoking cessation during pregnancy.
The specific aims are:
- (1) To compare smoking cessation rates and smoking reduction among pregnant smokers who are randomized to receive nicotine gum (2 mg dose) or a matching placebo;
- (2) To compare nicotine gum versus placebo on surrogate measures of maternal and fetal safety (i.e., overall nicotine and tobacco exposure at 6 weeks after the quit date and at 32-34 weeks gestation) and birth weight at the time of delivery;
- (3) To examine which subjects benefit the most from the use of nicotine gum for smoking cessation during pregnancy.
Subjects will be recruited from prenatal clinics that serve primarily a low-income, minority population. Two hundred sixty-eight pregnant smokers will be randomly assigned to receive smoking cessation behavioral counseling and either a 6-week course of mint flavored placebo or nicotine gum, followed by 6 weeks of decreasing doses. Maternal blood for genotyping will be obtained at study entry. Primary outcome measures will be 7-day point prevalence of cigarette abstinence, number of cigarettes smoked per day, urinary cotinine concentrations, and measures of tobacco exposure (i.e., carbon monoxide in exhaled air and urine anabasine and anatabine) at 6 weeks after the quit date and at 32-34 weeks gestation, and infant birth weight. We hypothesize that:
- (1) Pregnant smokers who are randomized to nicotine gum will have double the quit rates and will reduce their smoking to a greater degree than subjects randomized to placebo;
- (2) Nicotine gum compared to placebo will reduce maternal levels of tobacco-exposure markers and increase birth weights in the offspring;
- (3) The odds of cigarette abstinence will be increased primarily in subjects who smoke at least 15 cigarettes per day.