To determine the present risk of a Neural Tube Defect [NTD] pregnancy in the caucasian primigravid population in Dublin by comparing the serum folate and red cell folate status of primigravid patients attending the first prenatal booking clinic with data from the late 80's. This Cross-sectional population study looking at blood folate status of over 400 sequential primigravid caucasian women with a singleton pregnancy, booking at less than or equal to 20 weeks gestation. All patients were attending a prenatal booking clinic at the Rotunda Hospital in Dublin during 2003-2004. Comparing serum and red cell folate values in 454 primigravid patients in 2003-4 to values to in a large case-control study based on over 56,000 women attending maternity hospitals in Dublin from 1986 to 1990. Just 13.9% of our patients took periconceptual folate, 33.5% of patients took folate in the first 20 weeks of pregnancy and 58.8% of mothers were taking no folate supplement. Overall, 30% of mothers had RCF levels below 400 ug/L--a level recommended as the minimum value required for protection. NTD risk occurred most frequently amongst patients with RCF levels between 300 and 400 ng/mL.