Reducing secondhand smoke exposure among nonsmoking pregnant women: a systematic review

Abstract

Introduction: Exposure to second-hand smoke (SHS) in pregnancy leads to an increased risk of stillbirths, congenital malformations and low birth weight. There is a lack of evidence about how best to achieve reductions in SHS exposure among non-smoking pregnant women. This work systematically reviews individual or household interventions to reduce pregnant women’s exposure to SHS. Methods: MEDLINE, EMBASE and CINAHL databases were searched from their dates of inception to 17th April 2019. Studies were included if: participants were non-smoking pregnant women; involved an intervention to reduce SHS exposure or encourage partner quitting; and measured SHS exposure of pregnant women and/or recorded quit rates among partners. The UK National Institute for Health & Care Excellence (NICE) Quality Appraisal checklist was used to determine internal and external validity. Results: Nine studies met the inclusion criteria. Educational interventions were primarily targeted at the pregnant woman to change her or others’ behaviour, with only two studies involving the partner who smoked. Intervention delivery was mixed, spanning brief discussions through to more involving sessions with role play. The effective interventions involved multiple follow-ups. There was no standardised method of assessing exposure to SHS. Many of the included studies had moderate to high risk of bias. Conclusion: There is mixed evidence for interventions aimed at reducing pregnant women’s exposure to SHS, though multi-component interventions seem to be more effective. The effectiveness of family-centred approaches involving creating smoke-free homes alongside partner smoking cessation, perhaps involving pharmacological support and/or financial incentives, should be explored.