The focus of this chapter is on the most common type of tobacco use – cigarette smoking (smoking) – which involves burning tobacco and inhaling the products of this combustion. There are many other tobacco products that can be smoked and also some that involve tobacco use without burning, such as by ingestion or vapour inhalation. Tobacco products that can be smoked include cigarettes (manufactured or hand-rolled), cigars and loose tobacco used in pipes and waterpipes. Ingested (also called ‘smokeless’) forms of tobacco are generally intended for oral use and are sucked, chewed (dipped), gargled or applied to the gums or teeth, and fine tobacco mixtures can be inhaled into the nostrils (snuff).
Tobacco Use in Pregnancy
Types of Tobacco Use in Pregnancy
The focus of this chapter is on the most common type of tobacco use – cigarette smoking (smoking) – which involves burning tobacco and inhaling the products of this combustion. There are many other tobacco products that can be smoked and also some that involve tobacco use without burning, such as by ingestion or vapour inhalation.1 Tobacco products that can be smoked include cigarettes (manufactured or hand-rolled), cigars and loose tobacco used in pipes and waterpipes.1 Ingested (also called ‘smokeless’) forms of tobacco are generally intended for oral use and are sucked, chewed (dipped), gargled or applied to the gums or teeth, and fine tobacco mixtures can be inhaled into the nostrils (snuff).2 Electronic nicotine delivery systems (‘ENDS’ or e-cigarettes) do not burn tobacco leaves, but vaporize a solution (‘vaping’), which may or may not contain nicotine extracts from tobacco. Tobacco can also be inhaled through ‘second-hand smoke’ (SHS) exposure when someone else is smoking.
Physiological Effects of Cigarette Smoking in Pregnancy
Globally, over 5 million people per year die from cigarette smoking, and 12% of all deaths among adults aged 30 years and over were attributed to smoking in 2004.3 Most of the harm from smoking is believed to come from the toxins produced when tobacco is burnt. Smoking is considered to be one of the most significant potentially preventable risk factors in pregnancy and is associated with high rates of long- and short-term morbidity and mortality for mother and child, affecting all stages of human reproduction.4 Smoking is associated with reduced fertility and earlier onset of menopause,5 and serious complications, including abortion, pre-term birth, stillbirth, low birthweight and neonatal death.4 After birth, the effects of exposure to tobacco smoke are associated with an increased risk of sudden infant death syndrome and long-term adult disease for the child.1,4 There is also a much higher risk of children taking up smoking in adolescence themselves if their parents smoke.6
Epidemiology of Cigarette Smoking in Pregnancy
Globally, the prevalence of daily tobacco smoking among people aged older than 15 years decreased from around 41% in 1980 to 31% in 2012 for men and from approximately 11% to 6% for women.7 However, there are huge variations associated with different stages of the tobacco epidemic between high- and low-middle-income countries, particularly in regard to smoking in pregnancy prevalence. In high-income countries, the prevalence of smoking in pregnancy has been declining from more than 20% in the 1980s to around 10% in the 2010s.8,9 However, the decline has not been consistent across all sectors of society, with slower declines among women with lower socio-economic status10 and young women.9 Thus, smoking in pregnancy has become increasingly a marker of social disadvantage11 and understanding these disparities is central to understanding the tobacco epidemic.11 Women who continue to smoke in pregnancy are more likely to have a low income, higher parity, low levels of social support, limited education, access publicly funded maternity care12 and feel criticized by society.13 Additionally, women who smoke in pregnancy experience far more challenging lives, as measured across a range of psychosocial measures.14 Furthermore, the stigmatization of smoking in pregnancy has been an unintended consequence of anti-tobacco smoking campaigns,15 further compounding social isolation. There are also significantly higher rates of smoking during pregnancy among indigenous people.8 These disparities are largely in accord with social and material deprivation. However, in some migrant groups, disadvantage is not associated with smoking in pregnancy, suggesting cultural differences may cut across this social gradient.16 There are also strong psychological associations with smoking in pregnancy, including stress, depression and childhood trauma.17 In low- and middle-income countries there is marked variation in the prevalence of smoking in pregnancy, which reflects the dynamic nature of the tobacco epidemic in these regions.7 While rates of smoking in pregnancy have been low compared to high-income countries, these rates are increasing and the WHO has identified the rise of tobacco use among young females in low-income, high-population countries as one of the most ominous developments of the tobacco epidemic,1 jeopardizing efforts to improve maternal and child health.10
Gender issues are also important when thinking about smoking during pregnancy – when a woman’s role may be seen primarily as a ‘reproducer’, and emphasis is placed on the rights of the unborn child.18 There is a risk these arguments may be used to impose authority over women’s behaviour, ‘blaming’ women for their own plight and that of their children, and using guilt or other means to undermine self-confidence, further reducing the control women have in their lives.19
Understanding Nicotine Addiction and Why Women Smoke During Pregnancy
There are many personal, social, political and economic factors influencing young people starting to smoke,20 including a gesture against authority or to fit in with perceived social images or networks.20 Evidence about the social determinants of health suggests disadvantaged people are more likely to use substances in response to their circumstances.21
Nicotine is rapidly absorbed and reaches the brain within 10–16 seconds,20 which produces a cascade of actions, including release of ‘pleasure enhancing’ dopamine, which strengthens associations of positive feelings with smoking behaviour and appears to be involved in all addictive behaviours.22. Nicotine has a distributional half-life of 15–20 minutes and terminal half-life in the blood of 2 hours.20 The negative effects of withdrawal are thought to be the main drivers of ‘nicotine addiction’, starting within hours of the last cigarette, and are generally the most difficult during the first week.20 They include irritability, restlessness, feeling miserable, impaired concentration and increased appetite.20 While physiological adaptations in pregnancy accelerate nicotine metabolism,23 it is unclear whether withdrawal symptoms are different during pregnancy.24
Strategies to Reduce Smoking Prevalence
The WHO Framework Convention on Tobacco Control (WHO FCTC) is an evidence-based international treaty that guides action to reduce the harm from tobacco.25 In its preamble, the WHO FCTC acknowledges that there is clear scientific evidence that prenatal exposure to tobacco smoke causes adverse health and developmental conditions for children. Given concern about the increase in smoking and other forms of tobacco consumption by women and young girls worldwide, it calls for full participation of women at all levels of policy-making and implementation of the FCTC, and the need for gender-specific tobacco control strategies.1 The WHO FCTC outlines a comprehensive range of socio-ecological measures to reduce tobacco use, including pricing disincentives, regulation of tobacco products and sales to minors, environmental protection from exposure to tobacco smoke, education and community awareness, and cessation support programs.
Supporting Women to Stop Smoking During Pregnancy
Spontaneous Quitting During Pregnancy
Encouragingly, evidence shows that women who smoke are more likely to stop smoking during pregnancy than at other times in their lives, with approximately 50% of female smokers ‘spontaneously quitting’ before their first antenatal visit.26 This suggests that pregnancy, more than any other life event, motivates people who smoke to try to stop (Table 19.1).27
|Reasons to quit|
|Barriers to quitting to ask about|
However, these spontaneous quitting rates are lower among women with socio-economic disadvantage and other vulnerabilities.26 A systematic review of qualitative studies of perceptions of women who smoke during pregnancy describes how smoking was deeply embedded in women’s lives, but pregnancy triggered ‘intense feelings of personal responsibility and inadequacy’ and that women’s responses to social disapproval varied.28 For some, it provided an incentive to attempt to quit, while among others it resulted in increased smoking, either in response to the stress of social pressure or as an act of rebellion against it.28 Beliefs about smoking being a helpful ‘coping mechanism’ and concerns about weight gain were also reported as key concerns for some women.28 A review of barriers and facilitators to quitting smoking in pregnancy identified critical issues for women, including psychological wellbeing, relationships with significant others, changing connections with her baby through and after pregnancy, and appraisal of the risk of smoking. This review concluded that ‘for disadvantaged smokers, these factors are more often experienced as barriers than facilitators to quitting’.29 Women also raised concerns about weight gain. Growing evidence suggests that behavioural interventions that rely solely on the capacity of individuals to act independently (individual agency) are less effective than those that include structural support for socio-economically disadvantaged people.30
Thus, pregnancy offers a ‘window of opportunity’ to support women to stop smoking during frequent scheduled visits with healthcare providers.31 However, providers should understand the complexities of women’s lives and issues associated with smoking, which may be intensified during pregnancy. Stopping smoking is not easy for most women, and individual cessation support is best provided as part of a comprehensive strategy to reduce prenatal smoking.32
Interventions for Supporting Women to Stop Smoking in Pregnancy
There is strong evidence from Cochrane Systematic Reviews that psychosocial/behavioural interventions can increase the number of women stopping smoking in pregnancy (by 35%), and reduce the number of infants being born with low birthweight (by 17%) and admitted to a neonatal intensive care unit (by 22%) (Table 19.2).33 The number needed to treat (NNTB) for an additional beneficial outcome to prevent one infant being born low birthweight is 63 (95% confidence interval (CI) 39–203).There is also borderline evidence that nicotine replacement therapy (NRT) combined with behavioural support, might help women to stop smoking in later pregnancy.34 Thus, providing advice and support for all women to stop smoking during pregnancy is universally recommended in high-quality international guidelines.1,35,36 These recommendations are often summarized in acronyms such as the ‘5 As’ (Ask, Advise, Agree, Assist, Arrange follow-up)37 or ‘ABC’ (Ask, Brief advice, Cessation treatment) (Table 19.3).38
|Intervention||Effect||Quality of evidence|
|1. Ask all pregnant women about smoking in pregnancy|
|2. Advise all pregnant women who smoke to stop||Provide information about risks of smoking and reasons to quit|
|3. Agree on what support is wanted||Ask women about things that might be stopping them from wanting to quit and discuss what support they might want|
|4. Offer assistance to stop smoking|
|5. Arrange ongoing support and feedback||Follow-up at each pregnancy visit and offer ongoing feedback/monitoring|
Asking Women About Smoking During Pregnancy
Identifying women who smoke during pregnancy is the critical first step in enabling access to support to quit. Clinicians and health providers can be supported in this by adopting medical records systems that prominently indicate to the user whether or not a patient smokes. Ideally, smoking status within such medical records systems should be regularly updated so that clinicians always have up-to-date information about the patient’s smoking immediately prior to asking about this. When such systems are implemented, patients are more likely to be asked about their smoking, presumably because clinicians are prompted to enquire, but perhaps also because they can use contemporary smoking status data to phrase questions sensitively.39
However, there is ongoing debate about the most effective way of asking about smoking and identifying women who smoke during pregnancy. The stigma and guilt many women feel about smoking in pregnancy may make it harder to disclose to a health professional. In general, less direct questions, such as asking women to select ‘which statement best describes your smoking’ is more sensitive than simply asking women ‘do you smoke?’ (yes or no answer).40. Research among women using other substances in pregnancy suggests that leaving sensitive questions about maternal behaviour until later in the clinical encounter (when more rapport is established) and asking women to describe (smoking) behaviour among other people in the family/household first may further increase accurate disclosure.41
In the United Kingdom, to address these issues with disclosure, some antenatal healthcare providers have trialled offering all pregnant women routine exhaled breath carbon monoxide (CO) screening to identify those with high concentrations of CO who are most likely to be smokers. This routine method removes the need for women to disclose their smoking and is usually combined with referral to smoking cessation services for all who have CO levels above a pre-defined threshold. Smoking cessation services then contact referred women to offer stop smoking support. Evaluations suggest that this kind of ‘opt out’ referral pathway doubles the proportions of pregnant women who are identified as smokers, referred and most importantly, who subsequently stop smoking.42 Additionally, ‘opt out’ referrals have been well received by both pregnant women and staff tasked with implementing them.43 After considerable debate, routinely offering CO screening appears to be increasingly accepted by women and midwives, with the understanding that the reasons for screening are explained to women, and they are offered the opportunity to accept or decline like any other screening test in pregnancy.44 The optimal way to identify pregnant women who smoke and to assess their interest in receiving support will vary in different healthcare organizations; the next section discusses the ways in which clinicians can best help those pregnant women who smoke and who are motivated to try stopping.