Smoking Cessation During Pregnancy: Analysis of Psychosocial Interventions

A review published in the Cochrane Database of Systematic Reviews found that psychosocial interventions for supporting women to help them stop smoking during pregnancy can increase the number of women who stop smoking in late pregnancy, and can reduce the number of infants born with a low birthweight.

Counseling, feedback, and monetary incentives (such as a “Quit and Win” lottery program) appeared to be effective; the effects of health education and social support were less clear.

Catherine Chamberlain, a senior research fellow from the Aboriginal Health Domain at the Baker IDI Heart & Diabetes Institute in Melbourne, Victoria, Australia, and colleagues searched the Cochrane Pregnancy and Childbirth Group’s Trials Register as of November 13, 2015 and included in their review 102 randomized controlled trials with 120 intervention arms, as well as data from 88 randomized controlled trials involving more than 28,000 women. The main interventions analyzed were counseling (n=54), health education (n=12), feedback (n=6), incentives (n=13), social support (n=7), and exercise (n=1).

Results from the review showed that there was moderate to high quality evidence that psychosocial interventions:

• Increased the number of women who stopped smoking in late pregnancy by 35%
• Increased the average infant birthweight by 56 g
• Reduced the number of babies born with a low birthweight by 17%
• Reduced the number of babies admitted to neonatal intensive care immediately after birth by 22%
• Did not appear to have any adverse effects

Researchers found the following effectiveness for each intervention:

• Counseling had a clear effect on stopping smoking compared with usual care
• Interventions that provided feedback had a clear effect compared with usual care or when combined with counseling
• Financial incentives had a clear effect when compared with alternatives such as a non-contingent incentive intervention
• Health education was not clearly effective when compared with usual care or when it was part of a broader maternal health evaluation
• Social support was not clearly effective when provided by peers, partners, or as part of a broader intervention to improve maternal health
• Exercise and dissemination of counselling did not have a clear effect compared with usual care (as shown by 1 study of each of the 2 interventions)

“The pooled effects were similar for interventions provided to women who were poor,” the investigators wrote. “A clear effect was also seen with interventions among women from ethnic minority groups, but not among indigenous women (4 studies).”

The researchers also noted that pooled results suggest that interventions during pregnancy can actually reduce smoking cessation after birth. While some suggest that many smokers simply suspend smoking during pregnancy,^2,3,4 the relapse rates are similar to the rates in non-pregnant women.⁵ “These findings suggest there may be a need for different approaches to promote continued abstinence postpartum, including focusing on the benefits for the mother, without excessive emphasis solely on the benefits for the baby,” the researchers wrote.

The effects of these interventions on preterm births (19 studies) and stillbirths (8 studies) were unclear.

Summary

“Counseling, feedback, and financial incentives appear to reduce the number of women smoking in late pregnancy,” the investigators wrote. “However, the interventions and the context of the interventions need to be carefully considered. The effect of health education and social support is less clear.”

The researchers also noted that the intensity of support women received in both the intervention and comparison groups has increased over time.

Limitations

• Most of the studies were carried out in high-income countries, making it difficult to assess whether the findings are applicable in other contexts
• Generalizability is limited, as there may be differences between women who sought out studies vs the general population or women who were recruited
• Many studies did not provide information about the number of women who were eligible for inclusion or who were approached to participate in studies, which would have provided information about general acceptability of interventions or about selection bias in the studies
• Timing of the final assessment of smoking status varied considerably among the studies
• New trials on this topic were published during the preparation of this review and will be included in the next update

References

1. Chamberlain C, O’Mara-Eves A, Porter J, et al. Psychosocial interventions for supporting women to stop smoking in pregnancy [published online February 14, 2017]. Cochrane Database Syst Rev. doi:10.1002/14651858.CD001055.pub5
2. Stotts AL, DiClemente CC, Carbonari JP, Mullen PD. Pregnancy smoking cessation: a case of mistaken identity. Addictive Behaviors. 1996;21:459-471.
3. Lawrence T, Aveyard P, Cheng KK, Griffin C, Johnson C, Croghan E. Does stage-based smoking cessation advice in pregnancy result in long term quitters? 18-month postpartum follow-up of a randomized controlled trial. Addiction. 2005;100:107-116.
4. Flemming K, Graham H, Heirs M, Fox D, Sowden A. Smoking in pregnancy: a systematic review of qualitative research of women who commence pregnancy as smokers. J Adv Nurs. 2013;69:1023-1036.
5. Bombard JM, Farr SL, Dietz PM, Tong VT, Zhang L, Rabius V. Telephone smoking cessation quitline use among pregnant and non-pregnant women. Matern Child Health J. 2012;17(6):989-995.