Published online by Cambridge University Press: 30 June 2016
Introduction: Smoking during pregnancy is associated with adverse outcomes. Tobacco cessation in the general population is associated with weight gain. Aims: We sought to compare gestational weight gain (GWG) in women who quit smoking during pregnancy with those who continued smoking and non-smokers in two countries with high smoking prevalence in pregnancy. Methods: This study uses baseline data from a brief cessation intervention clustered randomised controlled trial; data were collected from clinical records and through questionnaires at post-partum hospitalisations during October 2011–May 2012. Women had attended one of 20 selected clusters of publicly funded prenatal care clinics in Argentina and Uruguay. Self-reported cessation was verified biochemically. Results: Of 2636 pregnant women, 29.9% were smokers at the beginning of pregnancy; among them 41.9% quit and 58.1% continued smoking. Most women (60.7%) had a normal pre-pregnancy body mass index (BMI). Adjusted mean weight gain was higher in quitters than in continuing smokers and non-smokers. Cessation increased GWG by 2.4 kg (95% confidence interval 1.3–3.4) after adjusting by pre-pregnancy BMI and other confounders in comparison with women who continued smoking(p < 0.001). Conclusions: GWG was slightly higher in women who quit smoking at any time during pregnancy.