Folic acid transport to the human fetus is decreased in pregnancies with chronic alcohol exposure.
BACKGROUND
During pregnancy, the demand for folic acid increases since the fetus requires this nutrient for its rapid growth and cell proliferation. The placenta concentrates folic acid into the fetal circulation; as a result the fetal levels are 2 to 4 times higher than the maternal level. Animal and in vitro studies have suggested that alcohol may impair transport of folic acid across the placenta by decreasing expression of transport proteins. We aim to determine if folate transfer to the fetus is altered in human pregnancies with chronic alcohol consumption.


RESULTS
Serum folate was measured in maternal blood and umbilical cord blood at the time of delivery in pregnancies with chronic and heavy alcohol exposure (n = 23) and in non-drinking controls (n = 24). In the alcohol-exposed pairs, the fetal:maternal serum folate ratio was ≤ 1.0 in over half (n = 14), whereas all but one of the controls were >1.0. Mean folate in cord samples was lower in the alcohol-exposed group than in the controls (33.15 ± 19.89 vs 45.91 ± 20.73, p = 0.04).


CONCLUSIONS
Our results demonstrate that chronic and heavy alcohol use in pregnancy impairs folate transport to the fetus. Altered folate concentrations within the placenta and in the fetus may in part contribute to the deficits observed in the fetal alcohol spectrum disorders.
Division of Clinical Pharmacology and Toxicology, Hospital for Sick Children, Toronto, Ontario, Canada.
Janine R
JR
Hutson
Brenda
B
Stade
Denis C
DC
Lehotay
Christine P
CP
Collier
Bhushan M
BM
Kapur
D000328:Adult; D000437:Alcoholism / Q000097:blood / Q000378:metabolism; D000438:Alcohols / Q000009:adverse effects*; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005315:Fetal Diseases / Q000378:metabolism; D005333:Fetus / Q000378:metabolism*; D005492:Folic Acid / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008431:Maternal-Fetal Exchange / Q000187:drug effects*; D011247:Pregnancy; D013997:Time Factors
D000438:Alcohols; D005492:Folic Acid