Prevalence and predictors of maternal smoking prior to and during pregnancy in a regional Danish population: a cross-sectional study

Abstract

Background Maternal smoking is still a major public health problem posing the risk of several negative health outcomes for both the pregnant woman and her offspring. The prevalence of maternal smoking in Denmark and other high-income countries has decreased continuously since the 1980s, and a prevalence below 10% of women who continue to smoke during pregnancy has been reported in studies after 2010. Previous studies have shown that low socioeconomic status is associated with maternal smoking. Information from the Danish Birth Register about maternal smoking shows that the prevalence of women who report to smoke in pregnancy has decreased continuously with 23.3% who reported ever smoking in pregnancy in 2000, 12.9% in 2010 and 9.0% in 2017. The aim of this study was to estimate the prevalence of maternal smoking at the time of conception and at 20 weeks of gestation in a regional Danish population, to describe differences in maternal characteristics among smokers, quitters and never-smokers, and to estimate predictors of smoking at the time of conception. Methods A cross-sectional study was conducted among pregnant women receiving antenatal care at the Department of Obstetrics, Zealand University Hospital, Denmark from August 2015 to March 2016 ( n = 566). The main outcome was smoking at the time of conception and at 20 weeks of gestation. The questionnaire also collected information about maternal, health-related and sociodemographic characteristics. Descriptive analysis was conducted, and multivariate logistic regression analysis was used to assess the potential associated predictors (adjusted odds ratio). Results The prevalence of self-reported smoking at the time of conception was 16% ( n = 90) and 6% smoked at 20 weeks of gestation ( n = 35), as 61% of smokers quit smoking during early pregnancy. Multiple logistic regression analysis showed that significant predictors for smoking at conception were the socioeconomic factors; ≤12 years of education, shift work and being unemployed. Conclusion The prevalence of self-reported maternal smoking in this regional Danish population of pregnant women is lower than seen in previous studies. However, predictors for smoking at the time of conception remain to be factors of low socioeconomic status confirming a social inequality in maternal smoking. Women at risk of smoking during pregnancy must be identified in early pregnancy or even before pregnancy and be offered interventions to help them quit smoking.

The importance of socioeconomic position in smoking, cessation and environmental tobacco smoke exposure during pregnancy

“…In the current study, findings concerning working status, even though not significant, align with those in the literature, that report occupation as a predictor for smoking before and during pregnancy 11,13,26 ; occupation is also commonly related to an individual education and income 44 . Research also supports that smoking is a habituated response to the circumstance of housewife, often associated with economic vulnerability 45 .…”

“…As reported by other authors 11,13,22 , in our study, educational disadvantage was found to be a predictor of smoking status during pregnancy; participants who belong to the highest educational levels had a lower probability of smoking. In Portugal, these inequalities in pregnant smoking women have also been previously described 16 .…”

“…In line with prior research on the role of demographic characteristics on maternal consumption in pregnancy 11,23,25,40 , the current study suggests that mid-age women (older than 25 years-old), probably due to individual life circumstances and higher understanding of harms related to smoking, are less likely to smoke. Other relevant predictors of smoking among pregnant women identified in previous studies include parity 11,24 , and alcohol consumption 13,23 . Nevertheless, in our study, after adjustment for significant variables, there was no significant association between parity or alcohol use and smoking status.…”

“…Educational level may not only increase the likelihood of awareness of harmful effects of smoking during pregnancy 41 , but also of access to cessation programs 42 . In fact, several studies have noted that more highly educated women were more likely to quit smoking during pregnancy 11,22,43 . In our findings, a significant association was also found between educational levels (an indicator of SEP) and smoking cessation, indicating that continuers were more often those with lower education and with unskilled work.…”

Experts’ Views on Behaviour Change Techniques for Smoking Cessation in Pregnancy: A Qualitative Study

“…A recent study highlighted the correlation between higher tobacco store density and lower socioeconomic status with higher smoking-during-pregnancy rates [ 13 ]. Another study found predictors of maternal smoking during pregnancy related to women from lower socioeconomic backgrounds; these included unemployment, less time in education and women living alone [ 14 ]. Barriers related to psychological well-being were also identified as being highly influential; for example, women can perceive the stress related to a quit attempt to be more detrimental to their mental health and the health of the baby than continued smoking [ 12 ].…”