Maternal smoking during pregnancy in relation to adolescent anxiety and poor mental health: A cross-sectional study based on NHANES 2007-2012.

INTRODUCTION: Maternal smoking during pregnancy (MSDP) has been suggested as a potential contributor to adolescent mental health problems, yet existing evidence remains inconsistent. This study aimed to examine the association between MSDP and anxiety and poor mental health outcomes among US adolescents. METHODS: This is a secondary analysis of pooled cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) 2007-2012, which employs a complex, multistage probability sampling design to ensure national representativeness. A total of 1445 adolescents aged 12-15 years were included. MSDP was assessed via parental report. Anxiety and poor mental health symptoms were measured by self-reported numbers of days feeling anxious or mentally unwell in the past 30 days. Weighted negative binomial regression and logistic regression models were used to estimate the rate ratio (RR) and odds ratio (OR), accounting for the complex survey design. Sensitivity analyses were performed using unweighted logistic regression models. RESULTS: Of the participants, 14.9% were exposed to MSDP. The prevalence of high anxiety (23.2% vs 12.4%, p=0.002) and poor mental health (28.2% vs 12.3%, p=0.001) was greater in the MSDP-exposed group than in the unexposed group. After full adjustment, MSDP was associated with a 1.68-fold increase in the number of anxiety days (95% CI: 1.19-2.37) and a 1.97-fold increase in the number of poor mental health days (95% CI: 1.40-2.77). As categorical outcomes, MSDP was also associated with higher odds of severe anxiety (adjusted odds ratio, AOR=3.03; 95% CI: 1.45-6.29) and severe poor mental health (AOR=3.11; 95% CI: 1.55-6.24). Sensitivity analyses confirmed the robustness of these associations. CONCLUSIONS: In this cross-sectional study, MSDP was associated with a higher likelihood of anxiety and poor mental health in adolescents. Given the study design, causality cannot be established. Future longitudinal studies are warranted to confirm these findings and explore potential underlying mechanisms.