NEURAL-TUBE DEFECTS AND ELEVATED HOMOCYSTEINE LEVELS IN AMNIOTIC-FLUID

OBJECTIVE: Our purpose was to study maternal blood and amniotic fluid concentrations of homocysteine and relevant vitamins in relation to neural tube defects. STUDY DESIGN: Concentrations of total homocysteine, folate, and vitamins B-12 and B-6 were measured in maternal blood and amniotic fluid of 27 women carrying a fetus with a neural tube defect and 31 control women carrying a healthy fetus. RESULTS: The mean total homocysteine concentration in amniotic fluid of the study group was significantly higher than that of the control group. The mean concentrations of total homocysteine in blood and the vitamins folate, B-12, and B-6 in, respectively, blood and amniotic fluid were not significantly different between the groups. The mean concentrations of homocysteine and vitamin B-6 were significantly lower in amniotic fluid than in blood in both groups, whereas vitamin B-12 in amniotic fluid was higher than in blood. CONCLUSION: These results support the hypothesis that at least the cause of a subset of neural tube defects could reside in a primary or secondary maternal or fetal derangement of homocysteine metabolism.