Objectives: To compare blood concentrations of nicotine and cotinine and maternal and fetal hemodynamic effects resulting from use of nicotine gum versus cigarette smoking in pregnant smokers.
Methods: Pregnant women (24 to 36 weeks' gestation) who smoked chronically were randomly assigned with a 1:2 randomization scheme to either a group that smoked cigarettes (n = 10) or to a group that stopped smoking and chewed at least six pieces of nicotine gum (2 mg nicotine per piece) per day (n = 19). Blood nicotine and cotinine concentrations, maternal heart rate and blood pressure, uterine resistance index, and fetal heart rate and umbilical artery resistance index were obtained before and after one cigarette was smoked at baseline and after 5 continuous days of either chewing gum or smoking.
Results: A significant reduction from baseline in nicotine (p < 0.0001) and cotinine (p < 0.0025) concentrations was observed in those who chewed nicotine gum compared with those who smoked cigarettes. No significant differences in the changes in maternal or fetal hemodynamic parameters from baseline to estimated time of peak nicotine exposure were observed between those who smoked cigarettes and those who chewed nicotine gum.
Conclusion: Short-term use of nicotine gum delivers less nicotine than usual cigarette smoking in pregnant women.