“…Available estimates vary widely, from about 3% 15 to 30%, 1,[16][17][18] Most studies on prevalence have come from small clinical samples in maternity wards, 16 which often serve particular patient groups and communities, such as immigrant or minority groups, 19 rural communities, 20 adolescents, 21 and women from affluent areas. 22 A number of other studies include participants from rural and urban areas of the USA, 23 Canada, 24 Peru, 25 Mexico, 17 Rwanda, 26 Nigeria, 27 Saudi Arabia, 28 Iran, 16 as well as from India, 29 Pakistan, 30 UK, 15 and New Zealand. 31 Studies vary greatly in respect to the survey methods employed, which include face-to-face, telephone, computer-based and questionnaire interviews, which may affect response rates.…”