Success of smoking cessation interventions during pregnancy

Abstract

Background: Smoking during pregnancy is a modifiable risk factor associated with adverse pregnancy outcomes. Smoking during pregnancy has been shown to increase the risk of spontaneous abortion, prematurity, low birthweight, congenital malformations, and sudden infant death syndrome. Despite the fact that it is well known that smoking can lead to adverse pregnancy outcomes, 13-25% of pregnant women overall continue to smoke during this critical period.

Objective: The objective of the study was to evaluate the effect of gestational use of bupropion and nicotine patch replacement therapy on the risk of the following: (1) smoking cessation, (2) prematurity, and (3) small for gestational age.

Study design: Women included in the Quebec Pregnancy Cohort who filled the annual autoadministered questionnaire between Jan. 1, 1998, and June 30, 2009, were studied. Smokers before gestation with a pregnancy resulting in a live birth comprised the study population. Three mutually exclusive study groups were formed among those who smoked at the beginning of pregnancy: gestational users of nicotine patch replacement therapy, bupropion, and smokers who did not use nicotine patch replacement therapy or bupropion. Rate of smoking cessation during pregnancy as well as the risk of prematurity and small for gestational age were studied.

Results: Of the 1288 women who met inclusion criteria, 900 were smokers, 72 were bupropion users, and 316 were nicotine patch replacement therapy users. Bupropion and nicotine patch replacement therapy use during pregnancy were associated with higher rates of smoking cessation: 81% in the bupropion group; 79% for nicotine patch replacement therapy; and 0% in those not using buproprion or nicotine patch replacement therapy. After discontinuing smoking cessation medications, 60% of bupropion users and 68% of nicotine patch replacement therapy users did not smoke again during and after pregnancy. Adjusting for potential confounders, nicotine patch replacement therapy use was associated with a lower risk of prematurity (adjusted odds ratio, 0.21, 95% confidence interval, 0.13-0.34), and small-for-gestational-age (adjusted odds ratio, 0.61, 95% confidence interval, 0.41-0.90) compared to smoking. Bupropion was associated with a lower risk of prematurity only (adjusted odds ratio, 0.12, 95% confidence interval, 0.03-0.50).

Conclusion: Bupropion and nicotine patch replacement therapy have an impact on smoking cessation during and after pregnancy. Nicotine patch replacement therapy also decreased the risk of prematurity and small for gestational age.

Keywords: bupropion; nicotine patch replacement; prematurity; small for gestational age; smoking cessation during pregnancy.