Objective: To evaluate the prevalence of the awareness of and the behaviour towards folic acid in 2003 and the trend of folic acid use among pregnant Dutch women between 1995 and 2003 with regard to socio-economic status (SES). Method: We conducted 2-yearly cross-sectional studies among pregnant women who filled in a questionnaire during the first or second antenatal visit. The highest achieved level of education was taken as a proxy for SES. Results: In 2003 the general level of folic acid awareness was high but with significant differences relating to SES; a quarter of the lower educated women did not know about folic acid before pregnancy. Of the subjects with a lower SES 20% knew the correct period of use compared with nearly 50% in the...