A Randomized, Controlled Trial to Reduce Passive Smoking Exposure among Non-smoking Pregnant Women, in Sichuan Province, China

Abstract Objective: Passive smoking, which has been linked to increased risk of cancer and other diseases. The study was aimed to determine whether a motivational intervention for non-smoking pregnant women to build smoke-free home rules will lead to reduced passive smoking exposure. Methods: A total of 186 non-smoking pregnant women with smoking husbands recruited from eight district/county Women and Children's hospitals were divided randomly into control (N=95) and intervention group (N=91). The intervention included a series of motivational and patient communication activities, a resource booklet, clinician counseling, telephone hotline and regular telephone counseling. Self-administered questionnaire and nicotine concentrations in hair around the occipital bone were used to measure results. Hair nicotine concentrations were tested at baseline and one month post-intervention. Difference-in-differences (DID) approach and bias-corrected matching estimator was conducted to examine the efficacy of the intervention. Results: More non-smoking pregnant women for intervention group reduced the self-reported passive smoking exposure(52.5% versus 29.3%, p＜0.001). The geometric mean of nicotine concentration in the hair decreased by 1.58µg/g for intervention group and increased by 1.26µg/g for control group. The hair nicotine concentration was found statistically significant difference between the intervention group and control group by DID (p＜0.001). Conclusion: These findings demonstrate that there is a need to give emphasis to passive smoking in the home environment and enforcing smoke-free home rules is a strategy for protecting non-smoking pregnant women and their fetuses. Key word: Pregnant women, Passive smoking, Intervention