Factors associated with tobacco consumption during pregnancy in Portugal: a cross-sectional study

Abstract Background Tobacco consumption during pregnancy hinders mother and foetus health. Previous studies in Portugal have attempted to assess tobacco consumption and its associated factors; but none have studied representative samples. Objectives We aimed to estimate the prevalence of tobacco consumption during pregnancy in Portugal, and to determine sociodemographic, economic and healthcare access associated factors. Methods We performed a cross-sectional study using 2019 National Health Survey data. Women reporting a pregnancy between 2010 and 2019 were included. The outcome was daily or occasional tobacco consumption during pregnancy. Exposure variables were age group, nationality, marital status, region of residence, educational level, occupation/professional area, social support, net monthly income, and pregnancy trimester in the first surveillance appointment. Populational prevalence of tobacco consumption, and crude (PR) and adjusted prevalence ratios (aPR) with 95% confidence intervals (95%CI) were obtained using Poisson regression. Results Prevalence was 8.1% (95%CI: 5.6-11.4) (n = 744). PR was higher in young (PR: 1.4, 95%CI: 0.7-2.8), Portuguese (PR: 4.2, 95%CI: 1.1-16.4), single (PR: 1.6, 95%CI: 0.7-4.0) pregnant women, living in Azores (PR: 2.9, 95%CI: 1.0-7.9), with the 9th grade (PR: 4.9, 95%CI: 1.8-13.9), manual job (PR: 4.2, 95%CI: 1.2-14.2), weak social support (PR: 3.3, 95%CI: 1.3-8.7), 3rd income quintile (PR: 4.5, 95%CI: 1.0-19.9), 2nd or 3rd trimester appointment (PR: 2.1, 95%CI: 0.8-6.0). aPR was higher in pregnant women with the 9th grade (aPR: 4.7, 95%CI: 1.7-13.4) or high school (aPR: 4.0, 95%CI: 1.5-10.8) and weak social support (aPR: 2.9, 95%CI: 1.2-6.6). Conclusions The prevalence of tobacco consumption during pregnancy in Portugal was comparable to the European Region. Portuguese pregnant women, with less than tertiary education, and weak social support showed higher prevalences. Key messages • The prevalence of tobacco consumption during pregnancy in Portugal was 8.1%. Pregnant women with less than tertiary education, and weak social support showed higher prevalences of tobacco consumption. • Overall, smoking is more prevalent in socioeconomically disadvantaged pregnant women thus contributing to increased health inequities.