McDonnell BP, et al. - Via performing a prospective observational cohort study, the obstetric outcomes and socio-demographic factors in electronic cigarette (EC) users vs cigarette smokers and non-smokers in pregnancy were determined. In the setting of a large urban maternity hospital, researchers identified reports of live birth in 218 women with exclusive EC use and in 195 women with dual use of both cigarettes and EC during the study period. Infants born to EC users vs non-smokers had comparable birthweight but relative to infants born to cigarette smokers, had significantly greater birthweight. Infants born to dual users of both cigarettes and EC vs those of smokers had similar birthweights.