Women's Longitudinal Patterns of Smoking during the Pre-Conception, Pregnancy and Postnatal Period: Evidence from the UK Infant Feeding Survey.

BACKGROUND: An understanding of women's longitudinal patterns of smoking during the pre-conception, pregnancy and postnatal period and the factors associated with these patterns could help better inform smoking cessation services and interventions. METHODS: Latent class analysis (LCA) was used to empirically identify women's smoking patterns in a sample of 10,768 mothers from the 2010 UK Infant Feeding Survey. Multinomial logistic regression was used to identify characteristics associated with these patterns. RESULTS: LCA identified five distinct smoking patterns during the pre-conception, pregnancy and postnatal period: "non-smokers" (74.1% of women); "pregnancy-inspired quitters" (10.2%); "persistent smokers" (10.1%); "temporary quitters" (4.4%); and postnatal quitters (1.1%). Smoking patterns varied markedly according to socio-demographic variables and parity. After adjusting for these variables, mothers who lived during pregnancy with a partner who smoked were more likely to be temporary quitters (aOR 2.64, 95% CI 1.74-3.99) or persistent smokers (aOR 3.32, 95% CI 2.34-4.72) than pregnancy-inspired quitters. Mothers who lived during pregnancy with someone else other than a partner who smoked were more likely to be persistent smokers (aOR 2.34, 95% CI 1.38-3.97) or postnatal quitters (aOR 2.97, 95% CI 1.07-8.24) than pregnancy-inspired quitters. Mothers given information on how their partner could stop smoking if they lived during pregnancy with a smoking partner were less likely to be persistent smokers (aOR 0.42, 95% CI 0.27-0.65) than pregnancy-inspired quitters. CONCLUSION: Health professionals should ask about smoking at every opportunity, and refer women who self-report as current smokers to an evidence based smoking cessation service.