Prenatal anxiety, tobacco use, and infant birth weight: a multilevel analysis of PRAMS data

Abstract Purpose Maternal anxiety is a clinically relevant mental health concern during pregnancy and may contribute to reduced fetal growth, particularly when co-occurring with prenatal tobacco use. To examine the individual and contextual associations of maternal anxiety and prenatal tobacco use with infant birth weight using 2021–2023 Pregnancy Risk Assessment Monitoring System data. The analytic sample included 29,288 mothers nested within 11 states or jurisdictions. Methods Two-level linear mixed models were estimated to predict continuous infant birth weight, with a random slope for maternal anxiety to assess whether the anxiety–birth weight association varied across states or jurisdictions. Results Prenatal tobacco use was associated with an approximately 219-gram reduction in birth weight ( p < .001), while maternal anxiety was associated with an approximately 60-gram reduction ( p < .001). State-level prevalence of anxiety and tobacco use did not directly predict birth weight; however, the association between maternal anxiety and birth weight varied across states or jurisdictions. Conclusions These findings support integrated prenatal care approaches that combine maternal mental health screening, tobacco cessation support, and attention to contextual systems that may shape maternal and infant health.