Predictors of smoking cessation during pregnancy: a systematic review and meta-analysis

Aim: To identify factors found in the research literature to be associated with smoking cessation in pregnancy.

Methods: Electronic searches of the bibliographic databases of PubMed, EMBASE, PsycINFO, Elsevier, Scopus and ISI Web of Science were conducted to April 2017. All studies reporting factors associated with smoking cessation or continuing smoking during pregnancy were included and reviewed systematically, irrespective of study design. The Newcastle-Ottawa Quality Assessment Scale was used to assess the study quality. The DerSimonian & Laird random-effects model was used to conduct meta-analyses, and where effect estimates were reported for factors included in at least three studies.

Results: Fifty-four studies, including 505 584 women globally who smoked before pregnancy, 15 clinical trials and 40 observational studies, were included in the review and 36 (65.5%) were considered to be of high quality. This review identified 11 socio-demographic, seven socially related, 19 smoking behaviour-related, five pregnancy-related, six health-related and six psychological factors that were associated significantly with smoking cessation during pregnancy. The most frequently observed significant factors associated with cessation were: higher level of education, pooled odds ratio (OR), 95% confidence interval (CI) = 2.16 (1.80-2.84), higher socio-economic status: 1.97 (1.20-3.24), overseas maternal birth: 2.00 (1.40-2.84), Medicaid coverage or private insurance: 1.54 (1.29-1.85), living with partner or married: 1.49 (1.38-1.61), partner/other members of the household do not smoke: 0.42 (0.35-0.50), lower heaviness of smoking index score: 0.45 (0.27-0.77, lower baseline cotinine level: 0.78 (0.64-0.94), low exposure to second-hand smoking: 0.45 (0.20-1.02), not consuming alcohol before and/or during pregnancy: 2.03 (1.47-2.80), primiparity: 1.85 (1.68-2.05), planned breastfeeding:1.99 (1.94-2.05), perceived adequate pre-natal care: 1.74 (1.38-2.19), no depression: 2.65 (1.62-4.30) and low stress during pregnancy: 0.58 (0.44-0.77).

Conclusion: A wide range of socio-demographics, relationship, social, smoking-related, pregnancy-related, health and psychological factors have been found to predict smoking cessation in pregnancy.