Nicotine patches for pregnant smokers: a randomized controlled study.

To assess the effect of nicotine patches on continine-validated smoking cessation in pregnant women and the effect of nicotine on birth weight and preterm delivery. Pregnant women who smoked ten or more cigarettes after the first trimester (N = 250) were randomly assigned to receive nicotine patches (n = 124) or placebo patches (n = 126). Women randomized to nicotine were treated with 15-mg patches (16 hours/day) for 8 weeks, and 10-mg patches (16 hours/day) for 3 weeks. Overall, 26% stopped smoking and 14% were nonsmokers 1 year after delivery. There was no difference between nicotine and placebo groups. At the end of the intervention, the mean value of cotinine in saliva in women assigned to nicotine was 120 ng/mL and placebo 153 ng/mL (mean difference -33; 95% CI -72, 6 ng/mL). Mean birth weight difference was 186 g (95% CI 35, 336 g) higher in the nicotine than placebo group, and there was an insignificantly lower rate of low birth weight (under 2500 g) in the former group. There was no difference in the rate of preterm delivery between the two groups. Nicotine patches had no influence on smoking cessation during pregnancy, although they might increase birth weight in comparison with placebo.