Relationship between total homocysteine and folate levels in pregnant women and their newborn babies according to maternal serum levels of vitamin B12.
OBJECTIVE
To determine total homocysteine and folate levels in pregnant women according to vitamin B12 (B12) levels, and to analyse the impact of maternal B12 levels on the nutritional status of their newborn babies.


METHODS
Cross sectional observational study.


METHODS
Two public hospitals in Jundiai City, São Paulo, Brazil.


METHODS
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 B12 by enzyme immunoassay.


METHODS
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 B12 levels, but not between maternal B12 and neonatal red blood cell (RBC) folate. There was a weak correlation between maternal B12 levels and neonatal serum folate. However, there were significant correlations between maternal and neonatal total homocysteine levels and between neonatal B12 and neonatal total homocysteine levels. Mean (+/- SD) umbilical cord blood B12, RBC folate, serum folate and total homocysteine levels were 1.7 +/- 0.8, 1.8 +/- 0.8, 2.2 +/- 0.8 and 0.9 +/- 0.3 times higher than maternal B12, RBC folate, serum folate and total homocysteine values, respectively.


CONCLUSIONS
These data suggest that pregnant women with low B12 levels are unable to provide the necessary amount of B12 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.
Department of Clinical Chemistry and Toxicology, Faculty of Phamaceutical Science, University of São Paulo, Brazil.
Elvira M
EM
Guerra-Shinohara
Adriana A
AA
Paiva
Patrícia H C
PH
Rondo
Kátia
K
Yamasaki
Carolina A
CA
Terzi
Vânia
V
D'Almeida
D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005492:Folic Acid / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D009752:Nutritional Status; D011247:Pregnancy / Q000097:blood*; D012044:Regression Analysis; D014805:Vitamin B 12 / Q000097:blood*
D015415:Biomarkers; D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12