This study is reported as (1) a Cochrane review and (2) a Health Education Journal article. The abstracts for both appear below.

1. Interventions for promoting smoking cessation during pregnancy

Background

Smoking remains one of the few potentially preventable factors associated with low birthweight, preterm birth and perinatal death.

Objectives

To assess the effects of smoking cessation programs implemented during pregnancy on the health of the fetus, infant, mother, and family.

Search strategy

We searched the Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Tobacco Addiction Group trials register (July 2003), MEDLINE (January 2002 to July 2003), EMBASE (January 2002 to July 2003), PsychLIT (January 2002 to July 2003), CINAHL (January 2002 to July 2003), and AUSTHEALTH (January 2002 to 2003). We contacted trial authors to locate additional unpublished data. We handsearched references of identified trials and recent obstetric journals.

Selection criteria

Randomised and quasi-randomised trials of smoking cessation programs implemented during pregnancy.

Data collection and analysis

Four reviewers assessed trial quality and extracted data independently.

Main results

This review included 64 trials. Fifty-one randomised controlled trials (20,931 women) and six cluster-randomised trials (over 7500 women) provided data on smoking cessation and/or perinatal outcomes. Despite substantial variation in the intensity of the intervention and the extent of reminders and reinforcement through pregnancy, there was an increase in the median intensity of both 'usual care' and interventions over time.

There was a significant reduction in smoking in the intervention groups of the 48 trials included: (relative risk (RR) 0.94, 95% confidence interval (CI) 0.93 to 0.95), an absolute difference of six in 100 women continuing to smoke. The 36 trials with validated smoking cessation had a similar reduction (RR 0.94, 95% CI 0.92 to 0.95). Smoking cessation interventions reduced low birthweight (RR 0.81, 95% CI 0.70 to 0.94) and preterm birth (RR 0.84, 95% CI 0.72 to 0.98), and there was a 33 g (95% CI 11 g to 55 g) increase in mean birthweight. There were no statistically significant differences in very low birthweight, stillbirths, perinatal or neonatal mortality but these analyses had very limited power. One intervention strategy, rewards plus social support (two trials), resulted in a significantly greater smoking reduction than other strategies (RR 0.77, 95% CI 0.72 to 0.82). Five trials of smoking relapse prevention (over 800 women) showed no statistically significant reduction in relapse.

Authors' conclusions

Smoking cessation programs in pregnancy reduce the proportion of women who continue to smoke, and reduce low birthweight and preterm birth. The pooled trials have inadequate power to detect reductions in perinatal mortality or very low birthweight.

Plain language summary

Strategies can help support women to stop cigarette smoking in pregnancy so babies have better health

Cigarette smoking in pregnancy is common, particularly where there is low income and social disadvantage. Smoking in pregnancy increases the risk of babies having low birthweight and being born too early. Babies often struggle to cope with life outside the womb and can suffer ill health later in life. Many mothers find it hard to stop, or to reduce, smoking during pregnancy even knowing the benefits this may have, because smoking can help them cope with stress. There are effective strategies to help and support women to stop smoking that lead to fewer premature babies and better birthweights for babies.

This study should be cited as:

Lumley J, Oliver SS, Chamberlain C, Oakley L. Interventions for promoting smoking cessation during pregnancy. Cochrane Database of Systematic Reviews 2004, Issue 4. Art. No.: CD001055. DOI: 10.1002/14651858.CD001055.pub2.

2. Smoking cessation programmes in pregnancy: systematically addressing development, implementation, women’s concerns and effectiveness

Objectives

To increase a review’s relevance to practitioners and service users and identify the implications for systematic review methodology.

Methods

A systematic review of the effects of smoking cessation programmes implemented during pregnancy integrated process indicators and the vews of maternity service users and health promotion specialists. Additional qualitative data were extracted systematically from included randomised controlled trials (RCTs) to determine whether the design of interventions and conclusions arising from their evaluation related to the views of service users. On completing the review we reflected on the types of observational and qualitative research it drew on, where this research was incorporated into the review, and its added value.

Results

Incorporating process indicators into the review revealed: (1) problems with implementation and transplantation of some interventions and (2) studies with more stringent quality criteria and process evaluations demonstrated greater impact (weighted mean difference in smoking). Pregnant smokers were rarely involved in the design or evaluation of the interventions. Prior observational and qualitative studies and small scale consultations influenced the criteria by which the effectiveness of the interventions were judged, and revealed to what extent these criteria are adopted in practice.

Conclusions

Systematically abstracting data about the development and delivery of interventions revealed gaps that might be filled by the active involvement of service users.

This study should be cited as:

Oliver S, Oakley L, Lumley J, Waters E (2001) Smoking cessation programmes in pregnancy: systematically addressing development, implementation, women’s concerns and effectiveness. Health Education Journal 60 (4) 362–370.