The Public Health Interventions Advisory Committee (PHIAC) took account of a number of factors and issues when developing the recommendations.
3.1 PHIAC recognised that many of the women most likely to smoke during pregnancy live in circumstances which make it difficult for them to quit the habit. It believes that strategies which seek to address the wider socioeconomic factors linked to smoking would increase their chances of success.
3.2 The role of the family is important. The attitude of the family, including the woman's partner, towards smoking can have an effect on her smoking behaviour (and her health, if they smoke).
3.3 A range of effective interventions and services, such as NHS Stop Smoking Services, are available to help people quit smoking. Nevertheless, only a small number of women take up the offer of help during pregnancy or after childbirth. PHIAC believes a range of local approaches are needed to increase the number of these women who are referred to the services and who receive help.
3.4 PHIAC noted that the smoking, nicotine and pregnancy (SNAP) randomised control trial is currently testing the efficacy and safety of using nicotine patches with pregnant women. The results are due in 2011.
3.5 In studies, biochemical measures of carbon monoxide (CO) levels showed that women who said they had reduced the amount they smoked during pregnancy did not necessarily reduce their exposure to toxins. Additional evidence highlights the importance for a woman who is pregnant to quit smoking altogether – rather than just cutting down. This includes research showing that children are more likely to take up the habit if their parents smoke and data on the damage – for both mother and child – associated with continued exposure to secondhand smoke.
3.6 Women who are pregnant may receive mixed messages from health professionals about the benefits of cutting down as opposed to quitting smoking altogether.
3.7 US-based trials show that financial incentives are an effective way to encourage women who are pregnant to quit smoking. However, rigorous UK-based research is needed to take account of any cultural differences. The committee acknowledge that there is a need to avoid a proliferation of local evaluations which may be insufficiently powered or inappropriately designed to determine whether or not incentives are effective.
3.8 PHIAC was concerned to ensure health professionals in contact with pregnant women who smoke are not put off if their first offer of help to quit smoking is refused. As a result, the recommendations emphasise the importance of offering help to stop smoking throughout the pregnancy and beyond.
3.9 Professional barriers to tackling smoking among women who are pregnant or who have recently given birth include: lack of time, lack of resources and concern about jeopardising the professional relationship with the client. PHIAC believed that these issues can be addressed by referring the women for specialist help as part of normal practice.
3.10 Although many women quit smoking during their pregnancy, relapse rates are high and most start smoking again within 6 months of giving birth. PHIAC noted that the types of interventions that had been studied had not been effective in preventing relapse.
3.11 None of the studies of women who were pregnant included household members other than the partner (that is, the expectant father).
3.12 PHIAC acknowledged that encouraging practitioners to refer all pregnant women who smoke – even those who are currently unwilling to consider quitting – may create a need for additional stop-smoking resources. It also acknowledged that initially, at least, this may also lead to lower success rates. Nevertheless, the committee believed that higher referral rates are important in tackling smoking in pregnancy.
3.13 The cost-effectiveness model showed that interventions to encourage women who are pregnant to quit smoking were cost effective (in the main, they were more effective and less costly than not intervening). However, due to insufficient data, not all the effects of smoking during pregnancy were modelled. For instance, the model did not include the impact on subsequent infant morbidity and quality of life or healthcare costs for children aged over 5 years. If these factors had been included in the analysis, PHIAC believes the interventions would have probably been even more cost effective.