Introduction Argentina and Uruguay have a high prevalence of smoking during pregnancy. However, and despite national recommendations, pregnant women are not routinely receiving cessation counseling during antenatal care (ANC). We evaluated a multifaceted strategy designed to increase the frequency of pregnant women who received a brief smoking cessation counseling based on the 5As (Ask, Advise, Assess, Assist, and Arrange). Methods We randomly assigned (1:1) 20 ANC clusters in Buenos Aires, Argentina and Montevideo, Uruguay to receive a multifaceted intervention to implement brief smoking cessation counseling into routine ANC, or to receive no intervention. The primary outcome was the frequency of women who recalled receiving the 5As during ANC at more than one visit. Frequency of women who smoked until the end of pregnancy, and attitudes and readiness of ANC providers towards providing counseling were secondary outcomes. Women’s outcomes were measured at baseline and at the end of the 14- to 18-month intervention, by administering questionnaires at the postpartum hospital stay. Self-reported cessation was verified with saliva cotinine. The trial took place between October 03, 2011 and November 29, 2013. Results The rate of women who recalled receiving the 5As increased from 14.0% to 33.6% in the intervention group (median rate change, 22.1%), and from 10.8% to 17.0% in the control group (median rate change, 4.6%; P = .001 for the difference in change between groups). The effect of the intervention was larger in Argentina than in Uruguay. The proportion of women who continued smoking during pregnancy was unchanged at follow-up in both groups and the relative difference between groups was not statistically significant (ratio of odds ratios 1.16, 95% CI: 0.98–1.37; P = .086). No significant changes were observed in knowledge, attitudes, and self-confidence of ANC providers. Conclusions The intervention showed a moderate effect in increasing the proportion of women who recalled receiving the 5As, with a third of women receiving counseling in more than one visit. However, the frequency of women who smoked until the end of the pregnancy was not significantly reduced by the intervention. Implications No implementation trials of smoking cessation interventions for pregnant women have been carried out in Latin American or in middle-income countries where health care systems or capacities may differ. We evaluated a multifaceted strategy designed to increase the frequency of pregnant women who receive brief smoking cessation counseling based on the 5As in Argentina and Uruguay. We found that the intervention showed a moderate effect in increasing the proportion of women receiving the 5As, with a third of women receiving counseling in more than one visit. However, the frequency of women who smoked until the end of the pregnancy was not significantly reduced by the intervention.

Evidence of bias of self-reported smoking cessation during pregnancy is reported in high-income countries but not elsewhere. We sought to evaluate self-reported smoking cessation during pregnancy using biochemical verification and to compare characteristics of women with and without biochemically confirmed cessation in Argentina and Uruguay. In a cross-sectional study from October 2011 to May 2012, women who attended one of 21 prenatal clinics and delivered at selected hospitals in Buenos Aires, Argentina and Montevideo, Uruguay, were surveyed about their smoking cessation during pregnancy. We tested saliva collected from women <12 h after delivery for cotinine to evaluate self-reported smoking cessation during pregnancy. Overall, 10.0% (44/441) of women who self-reported smoking cessation during pregnancy had biochemical evidence of continued smoking. Women who reported quitting later in pregnancy had a higher percentage of nondisclosure (17.2%) than women who reported quitting when learning of their pregnancy (6.4%).

Argentina and Uruguay have a high prevalence of smoking during pregnancy, as well as of secondhand smoke (SHS) exposure. In this secondary analysis of a trial to implement brief smoking cessation counseling during antenatal care in Argentina and Uruguay, we aim to evaluate the effects of the intervention on the rates of self-reported SHS exposure at home and at work, and on attitudes recalled by non-smoker women enrolled in the intervention group compared with the control group. We randomly assigned (1:1) 20 antenatal care clusters in Argentina and Uruguay to receive a multifaceted intervention to implement brief smoking cessation counseling, which also included questions and counseling regarding SHS exposure, or to receive the standard of care. There was not a statistically significant difference between groups of the intervention’s effect (reduction of exposure to SHS) on any of the three exposure outcome measures (exposure at home, work or other indoor areas) or on the attitudes of women regarding exposure (avoiding breathing SHS and having rooms where smoking is forbidden). This analysis shows that we should not expect reductions in SHS exposure with this modest intervention alone. To achieve such reductions, strategies engaging partners and other household members may be more effective.