Amniotic Fluid B₁₂ And Folate Levels Associated with Neural Tube Defects

ABSTRACT

Amniotic fluid levels of B₁₂ and folate in neural tube defect (NTD) affected pregnancies were compared with the weekly group mean ±SD changes in amniotic fluid B₁₂ and folate levels of 10 unaffected pregnancies each week between 15 and 20 weeks' gestation age. Comparison was by analysis of variance (ANOVA) and Pearson's correlation to B₁₂ and folate levels and to the NTD samples of corresponding gestation age. Amniotic fluid B₁₂ and folate decreased 67 and 62%, respectively, between 15 and 20 weeks' gestation in the unaffected pregnancies, associated with an increase in amniotic fluid volume. The mean ±SD B₁₂ and folate of the NTD affected pregnancies (308 ±156 pg/mL and 3.1 ±1.6 ng/mL) were below the mean ±SD B₁₂ and folate of the total population of unaffected pregnancies (453 ±155 pg/mL and 3.9 ±1.2 ng/mL). The correlation between gestation age and amniotic fluid B₁₂ was -0.9914 (p ≤ .0001) and -0.9599 (p ≤ .002) for amniotic fluid folate. The B₁₂ levels of the affected pregnancies were below the range of unaffected pregnancies in four of the nine affected pregnancies, and folate levels in two of the nine affected pregnancies.

Keywords

Amniotic fluid - B₁₂ - folate