Household-smoking bans are associated with reduced nicotine exposure, increased smoking abstinence, and improved birth outcomes among pregnant women enrolled in smoking-cessation treatment.

Data indicate household-smoking bans aid cessation and reduce secondhand smoke exposure. This study assessed prevalence of antepartum (AP) and postpartum (PP) household-smoking bans and associations with nicotine exposure, abstinence, and birth weight among pregnant women. The current study is a secondary analysis of clinical trials examining the efficacy of financial incentives for smoking-cessation among pregnant women ( = 284). Participants were current smokers at the start of prenatal care and followed from ∼10 weeks gestational age through 24 weeks PP. Household-smoking rules and biochemically verified urinary cotinine were measured repeatedly. Nicotine exposure and birth weight were analyzed using analysis of covariance. Association with abstinence was analyzed using backward elimination logistic regressions. Prevalence of household-smoking bans increased from ∼ 45% to 55% AP and then increased to ∼80% PP. Women with a ban exhibited lower nicotine exposure in early and late pregnancy compared to smokers without a ban. Women with a ban at baseline or who adopted a ban early in treatment were more likely to be abstinent at late pregnancy and 24 weeks PP compared to women without a ban. There was a dose-response relationship between combined exposure (i.e., smoking and ban status) and infant birth weight, with infants of women who quit and reported a ban having the highest adjusted mean birth weight (3426 ± 63 g), while infants of women who continued smoking without a ban having the lowest (3153 ± 37 g). These results provide an empirical rationale for prospectively investigating whether adopting a household-smoking ban can reduce fetal exposure among pregnant smokers. (PsycInfo Database Record (c) 2021 APA, all rights reserved).