State of the Evidence

Smoking in Pregnancy

The risks of smoking in pregnancy are well established. Smoking in pregnancy results in serious health effects in both the woman and the foetus.  It has been shown to increase the risk of pregnancy complications and to cause serious adverse foetal outcomes including low birth weight, stillbirth, spontaneous abortions, decreased foetal growth, premature births, placental abruption and sudden infant death syndrome. Smoking during pregnancy also poses health risks to the woman such as decreasing folate levels, higher rates of miscarriage and reproductive problems, as well as the typical smoking-related health issues of lung cancer, respiratory disease, and heart disease.

In Canada, approximately 13%-18% of pregnant women use tobacco during pregnancy. Importantly, at least 30-40% of smokers quit during pregnancy – which is far higher than the cessation rates amongst the general population; moreover, the majority of those who quit report doing so “spontaneously” – or on their own – without formal intervention. However, this cessation is usually temporary.  Relapse rates vary, but are approximately 25% before delivery, 25% within one month postpartum, 50% within four months postpartum, and 70%–90% by one year postpartum.

Promising Approaches to Perinatal Tobacco Cessation

Health interventions designed over the past three decades to reduce smoking during pregnancy have not been resoundingly successful. Evidence indicates that the drop in smoking over time among pregnant women has been primarily caused by an overall decline in smoking rates among women of childbearing age, not by increased rates of smoking cessation related to pregnancy.

Our review suggests that this lack of success is because the determinants of smoking among pregnant and postpartum women in industrialized countries such as Canada generally reflect social disadvantage and yet these are rarely accounted for in interventions which focus on individual behaviour change.  The prevalence of smoking during pregnancy and postpartum is higher in pregnant women from lower socioeconomic groups as depicted by low income levels, lower educational attainment and low occupation status.

That said, certain smoking cessation interventions have proven to be effective – when implemented. Our review suggests that a dual need exists: to identify the most current effective interventions and to facilitate and promote effective knowledge translation and exchange between researchers and front line clinicians and workers.

Understudied Groups

Close analysis of statistics, data sources, and qualitative input from women and practitioners indicates that young pregnant women, women who drink alcohol and smoke during pregnancy, and pregnant women who have experienced trauma or violence constitute three specific groups with significant challenges in smoking cessation during pregnancy and postpartum. These groups of women remain underacknowledged in research and intervention development.

For example, in Canada, young women are the group most likely to smoke during pregnancy. During the last three months of pregnancy, more than one in four Canadian women under the age of twenty-five smoke. These young women not only smoke more during pregnancy, but they also experience lower success with cessation.

Little is known about promising approaches to smoking cessation for these three groups. The final report Expecting to Quit: A Best Practices Review of Smoking Cessation Interventions for Pregnant and Postpartum Girls and Women, 2nd edition, includes a new chapter reviewing what we do know about these groups: how their specific issues might affect cessation; how the issues of smoking, alcohol, youth, and trauma may interact and overlap for pregnant and postpartum women and girls; and what we might learn from mainstream pregnancy smoking-cessation programs.

Expecting to Quit: A Best Practices Review of Smoking Cessation Interventions for Pregnant and Postpartum Girls and Women, 2nd edition.   Download or Order
  • Every Woman has her own reasons for smoking.
  • Every woman can find her own way of quitting and staying smoke-free-in her own time.