Smoking behaviour in pregnancy and its impact on smoking cessation at various intervals during follow‐up over 21 years: a prospective cohort study

• Published in: BJOG : an international journal of obstetrics and gynaecology 2013-02, Vol.120 (3), p.288-296
• Main Authors: Rattan, D, Mamun, A, Najman, JM, Williams, GM, Doi, SA
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cohort study; Female; Follow-Up Studies; Gynecology. Andrology. Obstetrics; Health Behavior; Humans; Life Style; Medical sciences; Postpartum Period - psychology; Pregnancy; Prospective Studies; Risk Factors; risk reduction behaviour; Smoking - psychology; smoking cessation; Smoking Cessation - psychology; smoking during pregnancy; Tobacco, tobacco smoking; Toxicology; Young Adult
• ISSN: 1470-0328; 1471-0528
• DOI: 10.1111/1471-0528.12027

Please cite this paper as: Rattan D, Mamun A, Najman J, Williams G, Doi S. Smoking behaviour in pregnancy and its impact on smoking cessation at various intervals during follow‐up over 21 years: a prospective cohort study. BJOG 2013;120:288–296 Objective  To determine whether mothers who quit or reduce their level of smoking in pregnancy comprise a group of health‐conscious women who are disproportionally likely to adopt a healthier smoking lifestyle in the medium to longer term, compared with women who continue to smoke during pregnancy. Design  A prospective cohort study. Setting  A public hospital in Australia. Population  A cohort of 6703 individual mothers who completed both initial phases of data collection in 1981–1983; mothers who smoked daily (2992) before pregnancy were included in this study. Methods  Mothers were interviewed at 3–5 days post‐delivery, 6 months, 5 years, 14 years and 21 years to determine their smoking status. An inverse probability‐weighted Poisson regression with a robust error variance was fitted to the data using a log‐link function and a binary response variable for smoking outcome, and adjusting for several possible confounding factors. Main outcome measure  Smoking cessation at several follow‐up points, for up to 21 years. Results  Of the mothers who smoked daily before pregnancy, 12, 23, 37 and 41% reported having ceased smoking at 6 months and at 5, 14 and 21 years, respectively. The decision to quit smoking during pregnancy was found to be independently associated with a higher rate ratio (RR) of smoking cessation at 6 months (RR 30.60, 95% CI 20.50–45.69), 5 years (RR 4.36; 95% CI 3.61–5.27), 14 years (RR 2.42, 95% CI 2.12–2.75) and 21 years (RR 1.86; 95% CI 1.60–2.15), after adjusting for several possible confounding factors. Conclusions  Pregnancy appears to be an opportunity for successfully quitting smoking, regardless of socio‐economic circumstances or demographic background.