The object of this study was to explore the role of folate in the path
ophysiology of neural tube defects (NTD). Maternal and fetal serum and
red blood cell folate were assayed in 14 cases of NTDs and compared w
ith 14 controls with other malformations and matched for gestational a
ge (range 18-36 weeks). In mothers of NTD fetuses, serum folate (5.2 n
g/ml), red blood cell folate (294 ng/ml) and the folate methylation ra
te (65%) were significantly lower than in controls (6.6 and 399 ng/ml,
respectively, and 77%). However, the fetal folate status was similar
in cases and controls. In the NTD group, folate metabolism was altered
in the mothers but not in the fetuses. Therefore, a normal folate pla
cental transfer can be assumed in this group. In addition, it could be
speculated that decreased maternal folate methylation might be involv
ed in the pathogenesis of NTDs.