Plain English Summary
Background and study aims
Smoking in pregnancy remains an unresolved issue. Quit rates in pregnant smokers are low and advice by doctors and nurses, even when combined with behavioural support and nicotine replacement treatment (NRT), has only a limited effect. NRT (e.g. nicotine patch) has shown little effect most likely because pregnant women use them very little. Pregnant women also use up nicotine faster, and standard NRT doses may be too slow and too low for them. Nicotine patches also do not allow the dose to be tailored to smokers’ needs. Electronic cigarettes (EC) may overcome these limitations. ECs allow flexible dosing and have a faster effect than NRT. They also provide some of the sensations and enjoyment that smokers get from smoking. These characteristics should ensure better treatment uptake. It is estimated that in the UK half a million smokers have switched from smoking to vaping (EC use) so far, with some 20,000 quitting smoking with the help of EC per year who would not have quit otherwise. The EC must therefore be tested as a stop-smoking treatment for pregnant women, but the safety of such treatment needs to be addressed. ECs do not contain most of the chemicals responsible for health risks of smoking and those that are present are there at levels much lower than those present in cigarette smoke. The overall risks of EC use are estimated to be 95% less than risks of smoking. No chemicals other than nicotine have been identified in EC vapour that would be expected to affect the health of the baby. NRT is universally used by the UK pregnancy stop smoking services because pregnant smokers are consuming nicotine anyway and because the harm to the baby is also caused by other chemicals in tobacco smoke which are absent in NRT. The same logic applies to nicotine intake from ECs. The safety concerns are reduced by the fact that ECs would be used as a replacement for cigarettes which pose well known dangers. If there is any sign of an increased risk, the study can be stopped. If such use involves risks, evidence of this would have important practical implications. The aim of this study is to find out whether ECs are more effective at helping pregnant women to quit smoking than NRT.
Who can participate?
Women aged 18 or over, who are 12 to 24 weeks pregnant, smoke daily and want help with stopping smoking
What does the study involve?
Participants are randomly allocated to use either an EC or nicotine patches. The products are posted out to participants, and they are called by a stop smoking advisor shortly after to check they know how to use the product and to set a quit day. The advisor then calls the participant weekly for a further 5 weeks to provide support and check on their progress. Participants are followed up at the end of their pregnancy and also at 3 months after birth. Smoking quit rates and side effects from the two treatments are compared at end of pregnancy and at 3 months after birth.
What are the possible benefits and risks of participating?
The benefit to participants is that taking part may help them to stop smoking, improving not only their health, but also the health and wellbeing of their baby. A positive result would also provide a new, inexpensive, and practical way to tackle an important and so far unresolved problem. No risks to participants are expected. Nicotine patches are approved to be used in pregnancy, and ECs do not pose any risks greater than cigarettes, which participants are already smoking.
Where is the study run from?
Queen Mary University of London (UK)
When is the study starting and how long is it expected to run for?
May 2017 to April 2021
Who is funding the study?
NIHR Health Technology Assessment Programme (UK)
Who is the main contact?
Dr Dunja Przulj
011822; HTA 15/57/85
Helping pregnant smokers quit: a multi-centre randomised controlled trial of electronic cigarettes and nicotine patches
Smoking in pregnancy remains an unresolved issue. Quit rates in pregnant smokers are low and advice by doctors and nurses, even when combined with behavioural support and nicotine replacement treatment (NRT) has only limited efficacy. NRT has shown little effect most likely because pregnant women use them very little. Pregnant women also metabolise nicotine faster and standard NRT doses may be too slow and too low for them. Nicotine patches also do not allow dosing tailored to smokers’ needs.
Electronic cigarettes (EC) may overcome these limitations. EC allow flexible dosing and have a faster effect than NRT. They also provide some of the sensations and enjoyment that smokers get from smoking. These characteristics should ensure better treatment adherence.
The trialists hypothesise that EC may be more effective in helping pregnant women to quit smoking than NRT.
More details can be found at: https://www.journalslibrary.nihr.ac.uk/programmes/hta/155785/#/
London- South East Research Ethics Committee, 29/06/2017, REC ref: 17/LO/0962
Multi-centre open-label randomised controlled trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet
Randomisation will be conducted by a web-based application system created by the trialists' clinical trials unit. Randomisation will be in blocks of mixed sizes. Allocation is 1:1.
Participants will be randomised (1:1) to receive either nicotine patches for up to 8 weeks (15mg/16hr) or an e-cigarette starter pack. Both groups will receive weekly telephone support for 6 weeks from specialist stop smoking advisors. Participants will be follow up at the end of pregnancy and at 3 months postpartum.
Primary outcome measure
Prolonged abstinence rates at the end of pregnancy, defined as per Russell Standard (up to 5 lapses allowed from 2 weeks after the target quit day until end of pregnancy, with no smoking at all during the previous week at the time of follow-up), and verified by salivary cotinine (< 15 ng/ml) for those not reporting using any nicotine product and anabasine (< 1 ng/ml) for those reporting other forms of nicotine use.
Secondary outcome measures
1. Smoke intake and nicotine intake, measured by salivary anabasine and salivary cotinine levels, assessed for participants still using NRT or EC at end of pregnancy and for ‘dual users’
2. 7-day point-prevalence abstinence (not a puff in the last 7 days), self-reported at 4 weeks, end of pregnancy and at 3 months post-partum
3. Prolonged abstinence, self-reported at end of pregnancy and 3 months post-partum
4. Use of NRT and EC throughout pregnancy, measured by asking participants on how many days they used their products at each weekly contact and at follow-ups
5. Safety examined by looking at the proportion of participants reporting adverse events and serious adverse events in each group throughout pregnancy; proportion of participants in each group reporting adverse events and serious adverse events for themselves or their infant at 3 months post-partum; and differences in birth and maternal outcomes between the two groups
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Daily smokers
2. 12 to 24 weeks pregnant
3. Wants help with stopping smoking
4. Willing to be randomised to use either NRT or EC (to avoid selective drop-out and contamination)
5. Wiling to receive 6 weekly support calls over the phone plus two follow-up calls
6. Speaks English (to allow data collection via phone)
7. Aged 18 years or over
Target number of participants
Participant exclusion criteria
1. Known allergic reaction to nicotine skin patches (a contraindication for patch use)
2. Current daily use of NRT or EC
3. Taking part in another interventional trial
4. Serious medical problem or high-risk pregnancy (to avoid problems with follow-up and data collection)
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Queen Mary University of London
Health Technology Assessment Programme
NIHR Health Technology Assessment Programme, HTA
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The results of the study will be published in a high-impact peer reviewed journal.
IPD sharing plan
The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Dunja Przulj.
Once the study is published, if a researcher/academic requests the dataset or part of the dataset (for example if conducting a review/meta-analysis), then they will be provided with the Excel data file if necessary. Data is archived electronically for 20 years. Any data shared will be completely anonymised, and as consent has not been requested from participants for this.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)