Changes in folate supplementation, and in serum and red cell folate levels in antenatal patients over the course of a health promotion project for the prevention of neural tube defects.

We assessed the use of folic acid supplements and changes in serum and red cell folate levels in pregnancy over the course of a health promotion project in Western Australia by 4 cross-sectional studies of women attending a public antenatal outpatient clinic in 1992 (before the launch of the health promotion project), 1993, 1994, and 1995. A short questionnaire was completed and blood taken for estimation of serum and red cell folate. There was an increase in the proportion of women taking folic acid supplements in the first trimester (51.9% in the final phase) and before pregnancy (15% in the final phase of the study), and no change in the proportion taking other vitamin supplements. Serum and red cell folate levels increased significantly over the study period in both women taking and not taking folic acid supplements. The proportion of women who had seen the pamphlet used in the health promotion project rose to 35.4% in the third phase, and fell to 27.8% in the final phase. Coincident with the health promotion project, there was an increase in folate status in early pregnancy. However, most women were not taking folic acid supplements before they became pregnant and, hence may not have had sufficient folate at the time of normal neural tube closure.