Vapes and nicotine patches called safe for pregnant women quitting smoking

British and Australian researchers analyzed randomized trials and concluded that the use of e-cigarettes and nicotine patches as an aid to tobacco cessation was not associated with adverse pregnancy outcomes. A report of the work is published in the journal Addiction.

Tobacco smoking significantly increases the risk of adverse pregnancy outcomes such as miscarriage, preterm birth, birth weight deficiency, and tissue damage to various organs in the baby. There is little information on whether these effects are related to nicotine or other substances in tobacco smoke. Nicotine replacement therapy, mainly with nicotine-containing patches, is widely used to help pregnant women quit smoking, but data on their safety are scarce. Some women use e-cigarettes to quit tobacco during pregnancy, which are more affordable and effective, but because they are consumer rather than medical products, there is even less information on their safety.

To get to the bottom of this issue, Peter Hajek of Queen Mary University of London and colleagues from the UK and Australia conducted a secondary analysis of data from their randomized PREP trials. They randomized 1,140 women 12-24 weeks pregnant and motivated to quit smoking to either nicotine patches or e-cigarettes (restocked on demand for eight weeks) and received up to six sessions of psychological support per week by telephone. The work was based at 23 English hospitals and the Scottish Stop Smoking Service.

The women and their babies were followed up until three months after delivery. Researchers documented cigarette and substitution use, symptom trends (cough, dyspnea, sputum expectoration and audible wheezing in the bronchi), and saliva tests for the major nicotine metabolite cotinine. Complete data were obtained from 1095 female participants and included in the final analysis.

It turned out that women preferred electronic cigarettes: in the end, they were used by 47.3 percent of participants in the group compared to 21.6 percent in the group with patches. Those who quit smoking but switched to e-cigarettes had an average 45 percent decrease in salivary cotinine by the end of pregnancy; only one quitter had used patches by that time and had the test done. When regular cigarettes, vape or patches were used, cotinine levels increased by 19 percent for cigarettes and 16 percent for vape and patches.

The birth weight of the baby was on average the same at 3.1 kilograms (standard deviation 0.6 kilograms) for smokers who used and did not use additional replacement therapy. Those who quit smoking but used e-cigarettes or patches had a significantly higher average weight of 3.3 kilograms (standard deviation 0.7 kilograms) and did not differ from those who abstained from both smoking and nicotine replacement products. Substitution use did not affect the incidence of adverse pregnancy outcomes and adverse side effects among both quitters and smokers. Those who used e-cigarettes were, on average, significantly less likely to cough (relative risk 0.59) and expectorate sputum (relative risk 0.53) compared with those who did not use them and adjusted for tobacco smoking.

Based on the findings, the authors of the paper concluded that regular use of e-cigarettes or nicotine patches by pregnant smokers does not appear to be associated with any adverse pregnancy outcomes.

In 2022, the UK Department of Health published a major report on e-cigarettes, which showed that switching from tobacco to nicotine-containing vapes can significantly reduce health risks, but they are still harmful on their own (which is important to consider with the growing popularity of vaping among teenagers).