What Smoking Cessation Strategies are Most Effective for Pregnant Women?

A systematic review and meta-analysis published in the journal Addictive Behaviors examined the most successful ways to help pregnant women stop smoking.¹ The research, conducted in Spain in March 2022, examined a wide range of interventions. The information gives an updated understanding of the evidence, with the hopes of improving maternal, fetal, and infant health.

The authors used EMBASE, Cochrane, and PubMed databases in 2 stages to identify meta-analyses and systematic reviews examining this topic from January 2012 to January 2022, and then updated the searches based on studies that met their criteria. They focused on randomized clinical trials (RCT) that evaluated digital, psychosocial, and pharmacological interventions for adults over 18. These were compared with placebos, gentler interventions, or routine care. Two researchers performed the searches while a third reviewed selected studies. The authors used the AMSTAR scale to assess study quality and the Rob-2 tool to evaluate bias risk; the GRADE system was used to evaluate the evidence.

Nicotine and tobacco exposure during pregnancy are associated with a wide range of complications, including low birth weight, fetal growth restriction, premature birth, ectopic pregnancy, miscarriage, placental abruption, and fetal death.

“In exposed infants it increases the risk of asthma and respiratory infections, sudden infant death syndrome, and can give rise to adverse neurodevelopmental and cardiovascular effects,” researchers said.

There are also long-term health effects such as dyslipidemia, arterial hypertension, arrhythmias, increased insulin resistance, obesity, and impaired lung development that can last from childhood into adulthood, in addition to harmful epigenetic and genomic changes.

It's clear that pregnant women should refrain from nicotine and tobacco use. However, “almost 50% of women continue smoking during pregnancy,” researchers wrote, and “tobacco therefore ranks as the most important modifiable risk factor on which professionals who attend pregnant women should focus their efforts.” But what strategies are most effective to help pregnant women stop smoking?

Researchers used 63 RCTs that had 19,849 pregnant participants to find the most effective smoking cessation techniques. After the data was analyzed, researchers found that digital interventions such as videos, text messages, WhatsApp, and interactive computer programs were not statistically effective. Neither was exercise, short-term nicotine replacement therapy (NRT), bupropion, social support, or biofeedback. Data that showed long-term NRT could be helpful was judged as having low evidence quality.

The researchers said the most effective smoking cessation method was counseling, which could be boosted with financial incentives and doctor/nurse feedback interventions, and that “the results of this meta-analysis support the adoption of psychosocial interventions to promote smoking cessation during pregnancy (moderate-high quality evidence).”

Study strengths include consistent eligibility criteria and evaluation methods. In addition, all the studies used lab verification that the women had stopped smoking.

“A USA study among 4197 pregnant women aged 20 to 44 years compared questionnaire-based maternal self-reported smoking and serum cotinine concentrations, and found that 23% of pregnant smokers did not report tobacco use,” researchers said. This sets the study apart from other meta-analyses, which often rely solely on self-reported data and may be social desirability biased, the authors said.

Researchers noted that the inclusion of unpublished studies helped mitigate publication bias. They added that the focus on randomized controlled trials (RCTs) published after 2012 is justified because of the availability of high-quality systematic reviews and meta-analyses.

For study limitations, researchers said that a pregnant women’s abilities, needs, culture, and situation vary, and successful smoking cessation needs can be different depending on location and identity. Another limitation is that most of the studies in this review were done in the United States.

Lastly, researchers said that low socio-economic status pregnant women may benefit less from cessation interventions because they, “are usually heavier smokers that live in pro-smoking environments and could require more intensive and targeted interventions.”

Reference

1. Vila-Farinas A, Pérez-Rios M, Montes-Martinez A, et al. Effectiveness of smoking cessation interventions among pregnant women: An updated systematic review and meta-analysis [published online ahead of print, 2023 Sep 3]. Addict Behav. 2023;148:107854. doi:10.1016/j.addbeh.2023.107854