Prevalence of smoking during pregnancy
Authors: Patrick Doorley, Joan Hanafin
Journal: The Lancet Global Health (2018)

Shannon Lange and colleagues (July, 2018)1Lange S Probst C Rehm J Popova S National, regional, and global prevalence of smoking during pregnancy in the general population: a systematic review and meta-analysis.Lancet Glob Health. 2018; 6: e769-e776Summary Full Text Full Text PDF PubMed Scopus (231) Google Scholar report the results of a systematic review and meta-analysis of the scientific literature from 1985 to 2016 to estimate the prevalence of smoking during pregnancy by country, WHO region, and globally. Smoking during pregnancy leads to adverse effects for women and children and this much-needed report is welcome. Estimates for smoking during pregnancy were calculated via meta-analysis for 43 countries and via statistical modelling for 131 countries. At 38%, Ireland was reported to have the highest estimated prevalence of all countries. We enter a note of caution in relation to the figure for Ireland. The five studies used to calculate estimates for Ireland had small sample sizes (n=100 for the 1992 study, n=127 for the 1996 study, n=151 for the 2006 study, n=450 for the 2008 study, and n=1011 for the 2011 study), and the two very high prevalence rates were published in 1992 (62%) and 1996 (60·6%). In recent decades, Ireland has introduced a suite of tobacco control measures leading to substantial decreases in smoking prevalence in the general population and among pregnant women, specifically as a result of the 2004 smoking ban.2Kabir Z Daly S Clarke V Keogan S Clancy L Smoking ban and small-for-gestational age births in Ireland.PLoS One. 2013; 8: e57441Crossref PubMed Scopus (31) Google Scholar Smoking prevalence for women in Ireland was 32% in 19983Brugha R Tully N Dicker P Shelley E Ward M McGee H SLÁN 2007: survey of lifestyle, attitudes and nutrition in Ireland. Smoking Patterns in Ireland: Implications for policy and services, Department of Health and Children. The Stationery Office, Dublin2009: 8Google Scholar and had decreased to 14·7% in 2017,4Health Service ExecutiveSmoking Prevalence Tracker. Half Year—2017 Infographic.https://www.hse.ie/eng/about/who/tobaccocontrol/research/tracker-2017-update.pdfDate accessed: June 11, 2018Google Scholar although it was highest in the 25–34 year age group, at 26·1%. Two recent Irish studies5McCrory C Layte RJ Prenatal exposure to maternal smoking and childhood behavioural problems: a quasi-experimental approach.J Abnorm Child Psychol. 2012; 40: 1277-1288Crossref PubMed Scopus (18) Google Scholar, 6Reynolds CME Egan B McKeating A Daly N Sheehan SR Turner MJ Five year trends in maternal smoking behaviour reported at the first prenatal appointment.Ir J Med Sci. 2017; 186: 971-979Crossref PubMed Scopus (11) Google Scholar with large sample sizes from the time period of the study by Lange and colleagues (20125McCrory C Layte RJ Prenatal exposure to maternal smoking and childhood behavioural problems: a quasi-experimental approach.J Abnorm Child Psychol. 2012; 40: 1277-1288Crossref PubMed Scopus (18) Google Scholar and 20176Reynolds CME Egan B McKeating A Daly N Sheehan SR Turner MJ Five year trends in maternal smoking behaviour reported at the first prenatal appointment.Ir J Med Sci. 2017; 186: 971-979Crossref PubMed Scopus (11) Google Scholar) indicate that smoking prevalence in pregnancy is much less than the estimated 38% and continues to fall annually. Data from the national longitudinal study Growing Up in Ireland reported by McCrory and Layte5McCrory C Layte RJ Prenatal exposure to maternal smoking and childhood behavioural problems: a quasi-experimental approach.J Abnorm Child Psychol. 2012; 40: 1277-1288Crossref PubMed Scopus (18) Google Scholar showed that 28% of mothers whose children were born between 1997 and 1998 reported that they smoked during pregnancy, and this number fell to 18% of mothers whose children were born in 2007. A study7Reynolds CME Egan B McKeating A Daly N Sheehan SR Turner MJ Five year trends in maternal smoking behaviour reported at the first prenatal appointment.Ir J Med Sci. 2017; 186: 971-979Crossref PubMed Scopus (19) Google Scholar of over 42 500 women who passed through the Coombe maternity hospital in Dublin recorded annual decreases in smoking during pregnancy, with prevalence dropping from 14·3% to 10·9% between 2011 and 2015. The decrease in smoking during pregnancy is a positive development for public health policy in Ireland but further efforts are needed, especially among disadvantaged populations, if smoking-related risk to pregnant mothers, their infants, and children is to be further reduced. We declare no competing interests. National, regional, and global prevalence of smoking during pregnancy in the general population: a systematic review and meta-analysisSmoking during pregnancy is still a prevalent behaviour in many countries. These findings should inform smoking prevention programmes and health promotion strategies, as well as draw attention to the need for improved access to smoking cessation programmes for pregnant women. Full-Text PDF Open AccessPrevalence of smoking during pregnancyShannon Lange and colleagues1 published a systematic review and meta-analysis reporting the prevalence of smoking during pregnancy by country. As the authors highlighted, Uruguay is among the top three countries with the highest prevalence, and Argentina is situated in the group of countries with a prevalence between 10% and 15%. The burden of tobacco in pregnant women in these two countries is surprisingly high since both countries have adopted comprehensive tobacco control measures. Full-Text PDF Open AccessPrevalence of smoking during pregnancy – Authors' replyWe thank Patrick Doorley and Joan Hanafin from Ireland and Mabel Berrueta and colleagues from Argentina and Uruguay for their comments about our Article on the global prevalence of smoking during pregnancy.1 The comments from these researchers, who represent countries with a higher than average prevalence of smoking among pregnant women,1 along with the results of our study, highlight the need to establish national surveillance systems on prenatal tobacco use and other substance use that can be used to monitor the prevalence of substance use over time, study risk factors associated with substance use, investigate possible associations between prenatal substance exposure and maternal and child health outcomes, and assess the effectiveness of policy measures. Full-Text PDF Open Access