Electronic cigarettes (EC) use a battery element to heat a solution of water, propylene glycol or glycerine, nicotine and flavourings to produce an aerosol (Figure 1). This aerosol is inhaled by the user and provides a rapid peak plasma nicotine concentration within minutes, approaching that achieved by smoking a cigarette. EC do not produce carbon monoxide. Other harmful compounds, such as aldehydes and nitrosamines, are produced at a lower level than conventional cigarette smoking. The use of EC has increased substantially in recent years in the pregnant population.
The effects of electronic cigarette use in pregnancy are unknown and there are no data on obstetric outcomes amongst pregnant EC users. Our objective was to determine whether pregnant EC users are a distinct socio-demographic group compared to smokers and non-smokers. Additionally we sought to measure obstetric outcomes related to EC use in pregnancy.
Pregnant EC users appear to be a socioeconomic group distinct from smokers. Over four in ten pregnant EC users are also smoking cigarettes. The rate of ‘never smokers’ using EC users was surprisingly high at 8.4%, a figure much higher than the 1.4% quoted in the non-pregnant population. The use of EC in pregnancy is not associated with low birth weight. The incidence of fetal growth restriction was similar to non-smokers. There is no increase in adverse obstetric outcomes in EC users.