Predictors of tobacco use among pregnant women: a large-scale, retrospective study

Abstract

Objective To investigate the predictors of smoking among pregnant women in Iran, focusing on health literacy and associated socioeconomic factors. Methods This retrospective cohort study included 103,042 pregnant women aged 18–45 years who attended healthcare centers affiliated with Mashhad University of Medical Sciences for routine prenatal and postnatal checkups between 2017 and 2020. Data were collected from the Sina Electronic Health Record System (SinaEHR ® ), which recorded sociodemographic characteristics, medical history, and lifestyle behaviors, including tobacco use. Results Smoking prevalence was 0.9%. Women with undergraduate or higher education had significantly lower odds of smoking (OR = 0.36; 95% CI = 0.28–0.47) compared to those with primary education or less. Maternal age was marginally associated with increased smoking risk (OR = 1.01; 95% CI = 1.00-1.03). While unemployment showed an increased crude risk for smoking, this was not significant after adjustment (adjusted OR = 1.02; 95% CI = 0.86–1.21). Strong associations were found between tobacco use and alcohol consumption (OR = 46.3; 95% CI = 24.8–83.4) and opium addiction (OR = 23.4; 95% CI = 14.5–36.3). Chronic disease history also increased smoking odds (OR = 1.51; 95% CI = 1.17–1.92). Conclusion Lower education, substance use, and chronic disease are significant predictors of smoking among pregnant women in Iran. Targeted interventions to improve health literacy and address these factors are essential to reduce tobacco use during pregnancy.