Relationship between total homocysteine and folate levels in pregnant women and their newborn babies according to maternal serum levels of vitamin B₁₂

Abstract

Objective To determine total homocysteine and folate levels in pregnant women according to vitamin B 12 (B 12 ) levels, and to analyse the impact of maternal B 12 levels on the nutritional status of their newborn babies. Design Cross sectional observational study.Setting Two public hospitals in Jundiai City, São Paulo, Brazil.Sample Sixty-nine pregnant women and their respective newborn babies at the time of delivery.Methods Maternal blood was collected up to 8 hours before delivery. Umbilical cord blood was collected after the expulsion of the placenta. Total homocysteine was measured by high perfomance liquid chromatography, folate by ion capture methodology and B 12 by enzyme immunoassay. Main outcome measures Relationship between low maternal vitamin B12 levels and total homocysteine and folate levels in pregnant women and newborn babies. Results There was a significant correlation between maternal and neonatal B 12 levels, but not between maternal B 12 and neonatal red blood cell (RBC) folate. There was a weak correlation between maternal B 12 levels and neonatal serum folate. However, there were significant correlations between maternal and neonatal total homocysteine levels and between neonatal B 12 and neonatal total homocysteine levels. Mean (FSD) umbilical cord blood B 12 , RBC folate, serum folate and total homocysteine levels were 1.7 F 0.8, 1.8 F 0.8, 2.2 F 0.8 and 0.9 F 0.3 times higher than maternal B 12 , RBC folate, serum folate and total homocysteine values, respectively. Conclusions These data suggest that pregnant women with low B 12 levels are unable to provide the necessary amount of B 12 to their fetuses. The clinical consequences could be the presence of neurological abnormalities as well as the lack of utilisation of homocysteine for methionine transformation.

The Impact of Third Trimester Maternal Serum Vitamin B12 and Folate Status on Fetal Birth Weight. Is Maternal Serum Homocysteine a Predictor of Low Birth Weight Infants?

“…Our results showed significantly high serum homocysteine level of mothers of LBW infants compared to mothers of ABW infants (9.10 ± 5.9 vs. 7.6 ± 3.83 μmol/L respectively, P = 0.042) which is consistent with former studies which reported that higher total homocysteine was significantly associated with LBW but they suggested the cause of LBW is vitamin B12 deficiency rather than folate deficiency [3] [46] [47] [48]. On the other hand Guerra-Shinohara et al [4] found no correlation was detected between birth weight and maternal or neonatal biochemical variables (B12, RBC and serum folate and total homocysteine). In our study we revealed a strong significant positive correlation between maternal antenatal serum vitamin B12 and birth weight which is supported by Ahmed et al, and Frery et al [12] [49].…”

“…A progressive reduction in vitamin B12 levels has been documented to occur during pregnancy despite the maintenance of normal dietary intakes. Guerra-Shinohara et al [4] reported 37% decrease in vitamin B12 levels in pregnancy which considered owing to physiological changes in hormonal status and increase in plasma volume, and returned to pre-pregnancy levels within few weeks after delivery [5].…”

Abnormal Transmethylation/transsulfuration Metabolism and DNA Hypomethylation Among Parents of Children with Autism

“…Elevated maternal homocysteine can cross the placental membrane (Guerra-Shinohara et al 2002) and are correlated with fetal homocysteine levels (Murphy et al 2004). Elevation in fetal homocysteine and SAH could theoretically alter fetal methylation patterns and induce inappropriate gene expression during development that could affect predisposition to autism.…”

Cobalamin status in children

“…In the first year of life, plasma tHcy is strongly correlated to serum cobalamin, whereas the relation to serum folate is weak or absent (Minet et al 2000;Bjorke Monsen et al 2001;Guerra-Shinohara et al 2002;Molloy et al 2002). In infants ≤6 months, MMA is inversely related to cobalamin, but the MMA concentrations are higher through the range of cobalamin concentrations than in older children .…”