Randomized trial of nicotine inhaler for pregnant smokers

Background Smoking during pregnancy is a serious public health problem in need of better treatments. Nicotine replacement treatment (patch or gum) has not been shown in randomized, placebo-controlled trials to be efficacious for smoking cessation during pregnancy. However, the nicotine inhaler may have advantages over other nicotine replacement treatments because it replicates some of the sensory effects of smoking. Objective The purpose of the study was to examine the efficacy and safety of the nicotine inhaler for smoking cessation during pregnancy. We hypothesized that the nicotine inhaler compared with placebo would increase quit rates and reduce smoking during treatment and at the end of pregnancy, result in a higher birthweight and gestational age in the offspring, and reduce the incidence of preterm birth and low birthweight infants. Study Design We conducted a randomized, double-blind, placebo-controlled trial of the nicotine inhaler for smoking cessation during pregnancy. Pregnant women who smoked ≥5 cigarettes daily received behavioral counseling and random assignment to a 6 week treatment with nicotine or placebo inhaler, followed by a 6 week taper period. Throughout treatment, we assessed tobacco exposure biomarkers, cessation rates, and adverse events. We also obtained information on birth outcomes. The primary outcome was smoking cessation at 32–34 weeks’ gestation; secondary outcomes were smoking reduction, birthweight and gestational age, and the incidence of preterm birth or low-birthweight infants. We compared treatment groups on these measures using Student t tests, Fisher exact tests, and multivariate linear and logistic regression. Results Participants in the placebo (n = 67) and nicotine (n = 70) groups were comparable on baseline characteristics, although women in the placebo group reported a higher motivation to quit ( P  = .016). Biochemically validated smoking cessation rates were similar with nicotine and placebo (after 6 weeks of treatment: 4% [3 of 70] vs 3% [2 of 67], respectively, P P  = .220). Cigarettes per day decreased over time in both groups ( P P  = .022) and 6 weeks after the quit date ( P = .042), but not at 32–34 weeks’ gestation ( P  = .108). Serum cotinine levels, birthweight, gestational age, and reductions in carbon monoxide did not differ by group. However, the incidence of preterm delivery was higher in the placebo than the nicotine group: 15% (10 of 67) vs 4% (3 of 67), respectively, P  = .030). The incidence of delivering a low-birthweight infant was also higher in the placebo than the nicotine group: 15% (10 of 67) vs 6% (4 of 67), respectively, P  = .035, but not after adjusting for preterm delivery P  = .268. Conclusion Although the nicotine inhaler group did not have a higher quit rate during pregnancy than the placebo group, the outcome of preterm delivery occurred less frequently in the nicotine group.