UC Davis

Background and Aims: Substance and tobacco use is associated with poor maternal and child health outcomes. Although these have each been linked to lower breastfeeding rates when examined separately, studies have yet to examine how the combination of tobacco and other substance use influences breastfeeding initiation and continuation. The aim of this study was to examine how the combination of smoking tobacco and use of illicit substances influences the odds of breastfeeding initiation and continuation. Materials and Methods: This retrospective cohort study (n = 15,634) used survey data from the 2016-2018 Centers for Disease Control and Prevention (CDC) Pregnancy Risk Assessment Monitoring System from eight US states to examine the association of tobacco and illicit substance use with breastfeeding initiation and continuation (≥6 weeks). The odds of breastfeeding initiation and continuation for individuals with and without prenatal tobacco and illicit substance use, adjusting for maternal and infant characteristics, were estimated using weighted, multivariable logistic regression models. Results: The combination of prenatal tobacco and illicit substance use was associated with a 42% reduction in the odds of initiating breastfeeding (adjusted odds ratio [aOR] 0.58 [95% confidence interval, CI 0.39-0.87]) and a 39% reduction in the odds of breastfeeding for at least 6 weeks (aOR 0.61 [95% CI 0.41-0.92]) when compared with those without tobacco and substance use. Conclusion: The odds of breastfeeding initiation and continuation are significantly lower among individuals with both prenatal tobacco and illicit substance use. Future studies are needed to identify barriers to breastfeeding within this population, to inform patient-centered interventions aimed at overcoming these barriers.