Erythrocyte folate, plasma folate and plasma homocysteine during normal pregnancy and postpartum: a longitudinal study comprising 404 Danish women Folate is essential for normal DNA and RNA biosynthesis and is required for homocysteine metabolism (1). Overt deficiency may cause a variety of deficiency features including hyperhomo- cysteinaemia, megaloblastic anaemia and neuro- logical disease (2). It appears obvious that folate is essential for normal foetal development, and during pregnancy, women have an increased physiological need for this vitamin. There is convincing evidence that an inadequate intake of folate may impair the devel- opment of the neural tube, causing neural tube Milman N, Byg K-E, Hvas A-M, Bergholt T, Eriksen L. Erythrocyte folate, plasma folate and plasma homocysteine during normal pregnancy and postpartum: a longitudinal study comprising 404 Danish women. Eur J Haematol 2006: 76: 200–205. Ó Blackwell Munksgaard 2006. Abstract: Objective: To assess folate and homocysteine status during normal pregnancy and postpartum in a longitudinal set- ting. Methods: This study, performed in 1995–1996, comprised 404 healthy pregnant Danish Caucasian women residential in Copenhagen County. Women taking folic acid tablets or vitamin B 12 injections were not included. Dietary multivitamin supplements containing folic acid 100 lg or vitamin B 12 1 lg, taken by 34%, were discontinued at inclu- sion. Participants had normal renal function. Folate status [erythrocyte (Ery-) folate, plasma (P-) folate, P-homocysteine] was measured at 18, 32 and 39 wk of gestation and 8 wk postpartum when the women were lactating. Results: Through 18, 32 and 39 wk of gestation and post- partum, P-folate demonstrated a significant fall: median values were 14.4, 10.2, 9.3 and 8.9 nmol/L, respectively (P < 0.0001). The pre- valence of low P-folate <6 nmol/L increased during pregnancy from 0.7% to 19.0% postpartum (P < 0.0001). Ery-folate displayed a simi- lar, significant fall: median value was 0.84, 0.75, 0.65 and 0.55 lmol/L, respectively (P < 0.0001). The prevalence of low Ery-folate <0.40 lmol/L increased during pregnancy from 0.5% to 17.2% post- partum (P < 0.0001). P-homocysteine demonstrated a significant in- crease: median value was 6.4, 7.0, 7.7 and 10.8 lmol/L, respectively (P < 0.0001). The prevalence of P-homocysteine >13 lmol/L increased during pregnancy from 0.7% to 20.8% postpartum (P < 0.0001). The prevalence of low folate status (defined as P-folate <6 nmol/L and P-homocysteine >13 lmol/L) was 0%, 0%, 1.2%, and 8.4% at 18, 32 and 39 wk of gestation and 8 wk postpartum, respect- ively. Conclusion: Low folate status occurs among Danish pregnant women, especially in late pregnancy and postpartum during lactation. Despite new guidelines for folic acid supplement since 1997, only 13% of pregnant women followed the guidelines in 2003. The official recom- mendations for periconceptional folic acid supplement should be reconsidered and reinforced. Nils Milman 1,2 , Keld-Erik Byg 1 , Anne-Mette Hvas 3 , Thomas Bergholt 1 , Lisbeth Eriksen 1 1 Department of Obstetrics, Gentofte Hospital, University of Copenhagen, Denmark; 2 Department of Medicine B, Rigshospitalet, University of Copenhagen, Denmark; 3 Department of Clinical Biochemistry, Skejby Hospital, Aarhus University Hospital, Denmark Key words: folic acid; folic acid deficiency; homocysteine; hyperhomocysteinemia; lactation; postpartum period; pregnancy Correspondence: Nils Milman MD, Department of Medicine, B 2142, Rigshospitalet, DK-2100 Copenhagen, Denmark Tel: +45 35452601 Fax: +45 35452648 e-mail: milman@rh.dk Accepted for publication 28 October 2005 Eur J Haematol 2006: 76: 200–205 doi:10.1111/j.1600-0609.2005.00606.x All rights reserved Ó 2006 The Authors Journal compilation Ó 2006 Blackwell Munksgaard EUROPEAN JOURNAL OF HAEMATOLOGY 200