The use of e-cigarettes or nicotine patches during pregnancy does not seem to negatively affect the fetus. This is the result of a major UK study involving over 1100 pregnant women.
"The baby's birth weight was the same as for non-smokers, but significantly higher than for those who continued to smoke during pregnancy," the British researchers state.
Neither e-cigarette use nor nicotine patches affect the fetus when used for smoking cessation during pregnancy. This is the result of a randomized control trial that compared different forms of nicotine use during pregnancy with no nicotine use at all. The study was funded by the NHS.
Missing reality studies
E-cigarettes and other smokeless nicotine products are often used as smoking cessation aids. Especially among pregnant women. Although the use of smokeless nicotine is considered to be less harmful than smoking, there is a lack of real-life studies showing how it affects the fetus in the womb and the mother-to-be. Researchers at Queen Mary University London wanted to find out.
1100 pregnant smokers participated
1100 pregnant smokers admitted to hospitals in 23 cities in England and Scotland took part in the study. The researchers gave the women the option of using different tools to stay smoke-free, e-cigarettes or nicotine patches. They then divided the women into three groups. One group swapped cigarettes completely for e-cigarettes, one group stayed smoke-free using nicotine patches, and one group continued to smoke to some extent during pregnancy.
"It turned out that 47% of the women chose e-cigarettes and 21% chose nicotine patches. Some combined the products and others continued to smoke partially while using one of the nicotine products occasionally," the researchers write.
No difference between non-smokers and vejp users
The study started near the 12th week of pregnancy. To check the results, the researchers measured the levels of cotinine - a biomarker for measuring higher levels of nicotine in the blood. The samples were taken at the beginning and end of the study and at a follow-up three months after delivery.
Smoking during pregnancy has previously been linked to lower birth weight and several other birth complications. The results of the study showed that the babies of those who used e-cigarettes and nicotine patches as a substitute for cigarettes had a birth weight similar to that of babies of non-smoking mothers. It was also found that those who used alternatives to cigarettes had 45% lower levels of cotinine in their blood compared to the beginning of the study.
Smoking caused complications
Newborns of a smoking mother had the same or higher levels of cotinine in their blood as at the start of the study. This was regardless of whether they vejped or used patches in parallel to reduce cigarette intake. The babies of the women in this group also had significantly lower birth weights than babies in the other groups. The average weight was 3.1 kg compared to 3.3 kg.
The researchers also compared the incidence of other complications linked to smoking and newborns. Those who vejp or used nicotine replacement therapy did not differ, as a group, from non-smokers. However, there were some differences compared to smokers, although complications were low even in this group.
"E-cigarettes help pregnant smokers to quit smoking, without posing any detectable risks to pregnancy. This is true even when compared to quitting smoking without nicotine use." says Peter Hajek, addiction researcher and one of the researchers who led the study. "Using nicotine-containing aids to quit smoking during pregnancy thus appears to be a safe method. The harm caused by smoking during pregnancy, at least in the later stages, appears to be primarily due to other chemicals in tobacco smoke, rather than nicotine." notes Peter Hajek.
Same level of risk as nicotine medicines
Unlike Swedish authorities, UK health authorities currently recommend pregnant smokers to use smokeless nicotine. At least to the extent that they are unable to quit smoking by other means during pregnancy. However, many midwives and doctors have been reluctant to recommend e-cigarettes to pregnant women. This is despite the fact that, according to the UK Public Health Agency, the risks are on a par with other smokeless nicotine products classified as medicinal.
"Women who continue to smoke during pregnancy do so because they find it very difficult to quit. Therefore, it is important that doctors, pregnant women and their families are informed that it is indeed safe to use nicotine replacement products or e-cigarettes during pregnancy" says Linda Bauld, co-author of the study and Professor of Public Health at the University of Edinburgh.
The study was funded by government National Health Service and was recently published in the journal Addiction.
Sources for this article:
Addiction: Safety of e-cigarettes and nicotine patches as stop-smoking aids in pregnancy: Secondary analysis of the Pregnancy Trial of E-cigarettes and Patches (PREP) randomized controlled trial
Queen Mary University of London: Nicotine replacement products offer safe quit option for pregnant smokers
Facts about the study:
Participants who chose e-cigarettes in the study received a refillable starter kit (a simple One by UK E-cig Store mouth-to-lung system, with a power of 14 watts) and two 10 ml bottles of flavored e-liquid (18 mg/ml nicotine). Additional supplies of e-liquid were sent on request for up to 8 weeks. However, participants were allowed to purchase and pay for any replacement parts after 8 weeks.
Participants who chose nicotine patches received an initial 2-week supply of Nicorette Invisi 15 mg/16-hour nicotine patches. Additional supplies were available on request for up to 8 weeks. Participants were encouraged to access additional supplies of patches and/or other NRT products via their GP or local stop smoking service. In the UK, pregnant smokers receive NRT free of charge.
