Associations between maternal stress and smoking: findings from a population-based prospective cohort study

Aims To investigate associations between maternal stress and smoking prior to, during and 6 months after the pregnancy. Design A prospective population‐based cohort study. Setting Norway. Participants A total of 71 757 women in the Norwegian Mother and Child Cohort Study (MoBa) participating twice during pregnancy and at 6 months postpartum. Measurements Respondents' estimates of anxiety and depression, relationship discord and negative life events were measured, along with self‐reports of smoking behaviour and demographic variables. Smoking was assessed at gestation weeks 17 and 30 and at 6 months postpartum. Findings Of the 27.5% women who smoked at conception, 55.8% quit smoking during pregnancy. At 6 months postpartum, 28.9% of quitters had relapsed to smoking. In total, 12.9% of the sample reported smoking during the pregnancy. Adjusted for well‐known risk factors, women reporting high levels of anxiety and depression had a decreased likelihood of quitting smoking during pregnancy [odds ratio (OR) 0.80, 95% confidence interval (CI): 0.73, 0.88) and an increased likelihood of relapsing after delivery (OR 1.26, 95% CI: 1.11, 1.44). Both relationship discord (OR 0.82, 95% CI: 0.75, 0.90) and exposure to negative life events (OR 0.93, 95%: CI 0.90, 0.96) had a negative influence on quitting smoking during pregnancy but had no influence on relapse to smoking postpartum. Conclusions Maternal stress and relationship discord may inhibit smoking cessation during pregnancy and promote resumption of smoking after pregnancy in women who have achieved abstinence.