Prevalence of dual use of combustible tobacco and E-cigarettes among pregnant smokers: a systematic review and meta-analysis.

Background: As e-cigarettes gain popularity as potential tobacco cessation aids, concerns arise about their dual use with traditional cigarettes, especially among pregnant women, potentially subjecting both women and fetuses to heightened risks. This systematic review and meta-analysis aimed to determine the overall prevalence of dual use of tobacco smoking and e-cigarette use in pregnant women.

Methods: A literature search was conducted across databases including PubMed, Embase, Web of Science, and Cochrane on October 20, 2023. The included studies reported the number of pregnant women and the count of those who were dual users. Quality assessment was undertaken using the JBI tool. The pooled prevalence of dual use was determined via a random-effects model. All statistical analyses were executed using R software, version 4.3.

Prospero: CRD42023486020.

Results: Eighteen studies were analyzed, encompassing 5,983,363 pregnant women. The meta-analysis indicated an overall prevalence of 4.6% (95% CI: 2.0-10.3) for dual users with significant heterogeneity (I² = 100%). Subgroup analysis based on the country showed a prevalence of 4.9% (95% CI: 2.0 to 11.6) for USA and 8.1% (95% CI: 0.00 to 1.00) for UK. Meta-regression revealed reduction of prevalence of dual use from 2019 to 2023. A potential publication bias was indicated by the LFK index and the Doi plot.

Conclusion: The dual consumption of e-cigarettes and traditional tobacco in pregnant women is a significant health concern, with a notable prevalence. Given the established risks of tobacco smoking during pregnancy and the uncertainties surrounding e-cigarettes, more comprehensive research and public health interventions are urgently needed to address this issue.