This is a plain English summary of an original research article
Counselling services, including cognitive behavioural therapy and motivational interviewing, help women to stop smoking during pregnancy by increasing quit rates. Feedback and financial incentives may also be effective, though evidence is weaker for both. Education alone and peer support were not found to be effective. Some of the counselling interventions are already at least partly supplied through NHS Stop Smoking Services – two of the UK trials recruited through the Service.
When pooled together, these non-pharmacological interventions, called psychosocial interventions, increased the chances of quitting by over 40% and reduced the chance of giving birth to a low birthweight baby by 17%, and chance of admission to a neonatal ward by 22%.
Smoking during pregnancy is associated with poor health outcomes for mother and child. This high quality Cochrane review included 102 relevant trials in which the researchers had high confidence. It suggests that psychosocial interventions can help pregnant women quit, but that health education alone is not sufficient.
Interventions may need to be targeted for deprived and underserved populations, although it remains unclear how they should be implemented into routine pregnancy care.
Why was this study needed?
Smoking during pregnancy raises the risk of miscarriage, sudden infant death syndrome, stillbirth and a range of other serious health conditions. For expectant mothers, quitting smoking during pregnancy therefore offers health benefits for both mother and child.
Smoking rates in the UK have fallen since the 1980s, although the decline has not been consistent across society. For example, in Scotland 30% of women living in the most deprived areas continue to smoke during pregnancy, compared to 7% in the least deprived areas. This disparity has been cited as a major driver of inequalities in health outcomes between rich and poor.
This Cochrane review investigated the effectiveness of psychosocial interventions that aim to help women to stop smoking during pregnancy; these are non-pharmacological strategies that use cognitive-behavioural, motivational and other supportive approaches. This is the sixth iteration of the review, and updates the previous 2013 version.
What did this study do?
The systematic review included 102 randomised controlled trials (over 28,000 women) of psychosocial interventions that support smoking cessation in pregnancy, compared to either usual care or “less intensive” versions of the intervention.
Interventions were categorised as: counselling, including motivational interviewing and cognitive behaviour therapy; health education; feedback on how smoking is impacting the foetus during pregnancy; financial incentives offered in return for quitting smoking; social support from peers or partners; and exercise.
Nearly all studies were conducted in high-income countries; 18 were from the UK. This means the findings are generaliseable to an NHS audience. About half the trials explicitly included women with low socio-economic status. Trials with drug therapies were included if there were differing levels of psychosocial support in the trial arms.
Studies had a low risk of bias, and the main outcomes and findings were supported by high quality of evidence in which the researchers had high confidence.
What did it find?
- Counselling interventions improved quit rates from about 9% without to 13% with the interventions. A relative increase of about 44% compared with usual care (relative risk [RR] 1.44, 95% confidence interval [CI] 1.19 to 1.73; 30 studies). There was no difference between different types of counselling.
- Feedback also improved quit rates when compared with usual care, as long as it was provided in conjunction with other strategies, such as counselling (RR 4.39, 95% CI 1.89 to 10.21). However, the wide confidence interval indicates uncertainty in this result. In addition, this was from only two studies, one from Norway and one from the UK, and the UK study had a conflict of interest (the author had directorship of the company producing feedback cotinine tests).
- The evidence was unclear for health education, social support from peers or partners, incentive-based interventions and exercise.
- Pooling all the interventions together, women who received psychosocial interventions were 17% less likely to have a low birthweight baby (18 studies), and babies were on average 55.6g heavier at birth (95% CI 29.82g to 81.38g higher). There was also a 22% reduction overall in neonatal intensive care admissions (8 studies).
- Psychosocial interventions did not appear to have any adverse effects.
What does current guidance say on this issue?
The 2010 NICE guideline on stopping smoking in pregnancy and after childbirth recommends that cognitive behaviour therapy and motivational interviewing are effective interventions, as is structured self-help and support from NHS Stop Smoking Services.
The guideline further states that though the provision of incentives to quit has been shown to be effective in other countries, research is required to see whether it would work in the UK. They do not consider that giving pregnant women feedback on the effects of smoking on the unborn child and on their own health is effective.
What are the implications?
Counselling to stop smoking should be considered for women who are pregnant, or seeking to become pregnant. Studies suggest women expect and appreciate the support, and psychosocial interventions are more likely to improve women's psychological well-being than worsen it.
This study provides some information to help midwives to inform women of the likely risks to them and their baby. The provision of health education and risk advice alone is unlikely be sufficient, and so any education-based intervention should include additional components, such as counselling or feedback.
New trials have been published during the preparation of the review; these will be included in the next update.
The NIHR Dissemination Centre has produced a recent themed review of all NIHR funded studies on health promotion during pregnancy, including substantive research on smoking cessation initiatives.
Citation and Funding
Chamberlain C, O'Mara-Eves A, Porter J, et al. Psychosocial interventions for supporting women to stop smoking in pregnancy. Cochrane Database Syst Rev. 2017;2:CD001055.
Cochrane UK and the Pregnancy and Childbirth Cochrane Review Group are supported by NIHR infrastructure funding.
NHS Choices. Breastfeeding and smoking. London: NHS Choices; 2016.
NICE. Smoking: stopping in pregnancy and after childbirth. Public health guideline PH26. London: National Institute for Heath and Care Excellence; 2010.
Tappin DM, MacAskill S, Bauld L, et al. Smoking prevalence and smoking cessation services for pregnant women in Scotland. Substance Abuse: Treatment, Prevention, and Policy. 2010;5:1.
Wanless D. Securing Good Health for the Whole Population. London: TSO; 2004.
Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre