title: Alcohol use, smoking and their co-occurrence during pregnancy among Canadian women, 2003 to 2011/12.
abstract: BACKGROUND
  The co-occurrence of alcohol use and smoking during pregnancy has been shown to have a negative synergistic effect on fetal and perinatal risks. The objectives were to: 1) obtain an estimate of the prevalence of smoking during pregnancy in Canada by province and territory from 2003 to 2011/12; 2) determine if the prevalence of smoking during pregnancy has increased or decreased over time; 3) investigate whether smoking status is differentially associated with alcohol use during pregnancy; and 4) examine the risk factors predictive of alcohol use only, smoking only, and the co-occurrence of alcohol use and smoking during pregnancy.
  
  
  METHODS
  Secondary data analysis was conducted using five cycles of the Canadian Community Health Survey (CCHS; 2003, 2005, 2007/08, 2009/10 and 2011/12). The prevalence of smoking during pregnancy, and 95% confidence interval (CI) was calculated by province and territory and by year. The likelihood ratio test was used to determine if the prevalence of smoking during pregnancy has increased or decreased over time. The relationship between smoking status and alcohol use during pregnancy was explored using a quasi-Poisson regression model. A multinomial logistic regression model was utilized to determine which factors were predictive of alcohol use only, smoking only, and the co-occurrence of alcohol use and smoking during pregnancy.
  
  
  RESULTS
  In Canada, between 2003 and 2011/12, the weighted pooled prevalence of smoking during pregnancy was 14.3% (95% CI: 13.6%-15.0%). Women who smoked daily during pregnancy, occasionally during pregnancy, or had a lifetime history of smoking (but did not smoke while pregnant) were 2.54 (95% CI: 2.11-3.06, P < 0.0001), 2.71 (95% CI: 2.25-3.27, P < 0.0001), and 2.09 (95% CI: 1.85-2.37, P < 0.0001), respectively, times more likely to have consumed alcohol during pregnancy, compared to pregnant women who were lifetime non-smokers when controlling for age, household income, ethnicity and CCHS cycle. Risk factors that predicted alcohol use only, smoking only, and the co-occurrence of alcohol use and smoking during pregnancy differed.
  
  
  CONCLUSIONS
  It is apparent that smoking in any capacity, whether during pregnancy or not, increases the likelihood that a woman consumed alcohol while pregnant. Ascertaining smoking status among pregnant women and women of childbearing age could be a useful screening method for identifying those at-risk of consuming alcohol during pregnancy, and vice versa.
authors.affiliation: Social and Epidemiological Research Department, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, ON M5S 2S1, Canada; Institute of Medical Science, University of Toronto, Faculty of Medicine, Medical Sciences Building, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
authors.forename: Shannon
authors.initials: S
authors.lastname: Lange
authors.affiliation: Social and Epidemiological Research Department, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, ON M5S 2S1, Canada; Epidemiological Research Unit, Klinische Psychologie and Psychotherapie, Technische Universität Dresden, Chemnitzer Str. 46. 01187 Dresden, Germany.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Probst
authors.affiliation: Institut de Santé Publique d'Épiémiologie et de Développement, l'Université Bordeaux Segalen, 146 Rue Léo Saignat, 33076 Bordeaux cedex, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Quere
authors.affiliation: Social and Epidemiological Research Department, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, ON M5S 2S1, Canada; Institute of Medical Science, University of Toronto, Faculty of Medicine, Medical Sciences Building, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Epidemiological Research Unit, Klinische Psychologie and Psychotherapie, Technische Universität Dresden, Chemnitzer Str. 46. 01187 Dresden, Germany; Dalla Lana School of Public Health, University of Toronto, 155 College St, Toronto, ON M5T 3M7, Canada.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Rehm
authors.affiliation: Social and Epidemiological Research Department, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, ON M5S 2S1, Canada; Institute of Medical Science, University of Toronto, Faculty of Medicine, Medical Sciences Building, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Dalla Lana School of Public Health, University of Toronto, 155 College St, Toronto, ON M5T 3M7, Canada; Factor-Inwentash Faculty of Social Work, University of Toronto, 246 Bloor Street W., Toronto, ON M5S 1V4, Canada. Electronic address: lana.popova@camh.ca.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Popova
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology*; D002170:Canada / Q000453:epidemiology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys / Q000706:statistics & numerical data*; D006801:Humans; D011247:Pregnancy; D037841:Pregnant People / Q000523:psychology*; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D012959:Socioeconomic Factors
keywords: Alcohol use; Canada; Canadian Community Health Survey; Pregnancy; Prevalence; Smoking