The estimated prevalence of herbal use during pregnancy varies greatly from country to country with reported rates varying from 6-9% in Canada and the USA to 52-58% in Australia and the United Kingdom. With such differences in reported usage, a study was undertaken to characterise the prevalence of herbal medicine use pregnancy and the characteristics of herbal medicine users during pregnancy from a multinational perspective,as well as investigating the reasons for herbal medicine use and the sources of recommendation of use.