A Randomized Trial of Nicotine-Replacement Therapy Patches in Pregnancy
Are nicotine-replacement therapies safe and effective for smoking cessation during pregnancy?
Participants between the ages of 16 and 50 years old were recruited from seven hospitals in England between May 2007 and February 2010. All women were between 12 and 24 weeks’ gestation and had smoked 10 or more cigarettes daily before pregnancy, were currently smoking five or more cigarettes per day during the pregnancy, and had an exhaled carbon monoxide concentration of at least 8 ppm. All participants received behavioral cessation support and were also randomly assigned to 8 weeks of treatment with active nicotine patches (15 mg per 16 hours) or matched placebo patches. The primary outcome of interest was abstinence from the date of smoking cessation until delivery, and was validated by exhaled carbon monoxide measurement. Safety outcomes included adverse events related to pregnancy and birth.
Of the 2,410 women who expressed interest in the study, a total of 1,050 women were enrolled, of which 521 were randomly assigned to nicotine replacement therapy and 529 were assigned to placebo. No difference was observed in the abstinence rate (from quit date to delivery date) between the two groups (nicotine patch vs. placebo patch) with an unadjusted odds ratio for the nicotine replacement group of 1.26 (95% confidence interval, 0.82-1.96) for smoking abstinence. However, during the first month, the abstinence rate was higher among the nicotine replacement group compared to the placebo group (21.3% vs. 11.7%). Compliance was low for both groups, with 7.2% of women assigned to the nicotine replacement group and 2.8% of women assigned to the placebo group using patches for more than 1 month. Rates of adverse pregnancy and adverse birth outcomes were similar between the two groups.
The investigators concluded that adding a nicotine patch to behavior support for smoking cessation during pregnancy did not significantly increase the rate of abstinence or the risk for adverse events during pregnancy or with birth. However, low compliance significantly limited the assessment of safety.
These data suggest that nicotine replacement may be safe during pregnancy; however, as the investigators note, the low compliance limits this finding. Additional research regarding the factors that are associated with low compliance for smoking cessation will provide information on the design of future interventions for women who smoke during pregnancy.
Keywords: Odds Ratio, Risk, Nicotine, Exhalation, Postpartum Period, Tobacco Use Cessation Products, Smoking, Carbon Monoxide, Confidence Intervals, England, Pregnancy, Patient Compliance, Smoking Cessation
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