A new analysis of trial data on pregnant smokers, led by researchers at Queen Mary University of London, finds that the regular use of nicotine replacement products during pregnancy is not associated with adverse pregnancy events or poor pregnancy outcomes.
The study, published today in Addiction Journal, presents a secondary analysis of the Pregnancy Trial of E-cigarettes and Patches (PREP) randomized controlled trial. The study aimed to examine the safety of e-cigarettes (EC) and nicotine patches (NRT) when used to help pregnant smokers quit. The participants comprised 1140 pregnant smokers, and the measurements included nicotine intake compared with baseline, birth weight, other pregnancy outcomes, adverse events, maternal respiratory symptoms, and relapse in early abstainers.
The findings revealed that regular use of e-cigarettes or nicotine patches by pregnant smokers does not appear to be associated with any adverse outcomes. Specifically, the use of EC was more common than the use of NRT, and women who stopped smoking and used EC at the end-of-pregnancy (EOP) reduced their salivary cotinine by 45%. Additionally, there were no differences in birth weights between abstainers and smokers using nicotine products, suggesting that the use of EC and NRT in later pregnancy may not affect intrauterine growth.
Furthermore, the study found that use of nicotine products during pregnancy did not increase the risk of relapse to smoking in early abstainers. Additionally, the analysis of birth and maternal outcomes, adverse events, and relapse rates were adjusted for baseline characteristics associated with the outcomes, and no significant differences were observed between participants using nicotine products and those not using them.
Notably, respiratory symptom assessments revealed that EC users reported more improvements in cough and phlegm than non-users, with no changes in shortness of breath and wheezing. The study also analyzed changes in salivary cotinine levels and found that regular use of nicotine products was associated with specific changes in cotinine levels, with dual users and reducers showing different patterns of cotinine increase compared to abstainers and smokers. However, the study acknowledged limitations such as the reliance on self-reported abstinence and the limited statistical power in some comparisons due to a small sample size.
In conclusion, the research suggests that the regular use of e-cigarettes or nicotine patches by pregnant smokers does not appear to be associated with adverse outcomes.
The findings provide important insights into the safety of nicotine products as stop-smoking aids in pregnancy, offering valuable information for healthcare professionals and pregnant women seeking smoking cessation support.