Helping pregnant smokers quit: Multi-centre RCT of electronic cigarettes vs usual care.

Background: Smoking in pregnancy remains an unresolved issue. A number of interventions failed to show efficacy. Electronic cigarettes (EC) are a promising new option, with a realistic chance of providing practical help to pregnant smokers and their children. No study has tested EC in this context so far. EC 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 some 95% less than risks of smoking. Nicotine itself can have adverse affects on the foetus as shown in animal studies, although the only study that examined birth outcomes in a large cohort of women randomised to NRT or placebo detected no health risks. NRT is universally used by the UK pregnancy stop smoking services because pregnant smokers are consuming nicotine anyway and because the harm to foetus is also caused by other chemicals in tobacco smoke which are absent in NRT. The same logic applies to nicotine intake from EC. Regarding other chemicals in EC ‘vapour’, its main components are propylene glycol, which is approved for use in pregnancy (e.g. in asthma inhalers) and vegetable glycerol which has no known adverse effects. Some flavourings may over time affect the lungs, but to our knowledge, no chemicals other than nicotine have been identified in EC vapour that would be expected to affect the health of the foetus. The safety concerns are tempered by the fact that EC would be used as a replacement for cigarettes which pose well known dangers, and that in the trial setting, pregnant women would be closely monitored and that if there is any sign of an elevated risk, the trial can be stopped. Such a negative result would, in fact, be of significant value. EC are used by an increasing proportion of pregnant smokers. If such use involves risks, evidence of this would have important practical implications. Study design: Multi-centre RCT comparing usual care (behavioural support and nicotine patches) with the same behavioural support with EC instead. Usual care: Standard care across the Stop Smoking Services (SSS) ranges from advice by midwives through telephone support to standard SSS clinics to home visits by specialist advisors. Across these, interventions usually include behavioural support and provision of 16h nicotine patches for up to eight weeks. We propose to provide a representative intervention comprising of initial face-to-face advice by midwives followed by telephone counselling by SSS advisors with six weekly calls, accompanied by 16h nicotine patches. Experimental intervention: This will be the same as the control intervention, but instead of patches, participants will receive EC to use. Participants: Pregnant smokers (12 to 24 weeks gestation) who smoke daily and are interested in stopping smoking. Setting: Maternity services across the UK. Primary outcome: Prolonged smoking cessation, reported throughout pregnancy and validated by salivary cotinine and anabasine at end of pregnancy (36 weeks gestation to 4 weeks post-partum). Secondary outcomes: Changes in smoke intake and in nicotine intake indexed by salivary anabasine and cotinine levels, assessed for quitters currently using NRT/EC products and, and smokers currently using NRT/EC products; self-reported quit rates at 4 weeks and at end of pregnancy; 7-day point prevalence abstinence (end of pregnancy); use of NRT and EC throughout pregnancy. Safety outcomes: Adverse effects throughout pregnancy and birth and maternal safety outcomes at end of pregnancy and 3 months post-partum. Procedures and visits: Participants will attend a baseline visit with a research midwife, and would be randomised to either EC or Patch. A stop-smoking advisor would then post the relevant study product to the participant and call them to set a quit date. Weekly behavioural support phone calls will be conducted on the qui