Bush et al. [1] question the conclusion from our study [2] that 'Regular use of e-cigarettes or nicotine patches by pregnant smokers does not appear to be associated with any adverse outcomes' because in animal studies, nicotine in pregnancy damaged offspring in ways our study may not have detected; other chemicals in e-cigarettes may be dangerous; and the conclusion may provide false reassurance and confuse the public.The effects of forced very high chronic dosing used in animal studies have unclear relevance for voluntary intermittent self-dosing in humans [3] and have indeed not been confirmed in studies of pregnant women using nicotine replacement therapy [4]. There is, however, clear evidence that other components of cigarette smoke such as carbon monoxide and lead are fetotoxic [5,6]. There is, therefore, no doubt that removing smoke chemicals is beneficial for pregnancy, even if nicotine intake continues. Regarding other chemicals in e-cigarette aerosol, there is now a large body of evidence showing that they pose only a small fraction of the risks of smoking [7]. Regarding public misinformation and confusion, in sharp contrast to evidence, 57% of smokers in England believe that vaping is as harmful as or more harmful than smoking [8]. Bush et al. [1] support this opinion when they state that vaping in pregnancy may or may not be the lesser of evils. It is the gross misinformation about risks of vaping, rather than reassurances that vaping is much less dangerous than smoking, that threatens public health, because it puts smokers off using one of the best stop-smoking approaches we currently have. Both common sense and our results provide strong reassurances that for pregnant smokers who are unable to quit unaided, e-cigarettes are a valuable option.