Determinants of folate status in pregnant women: results from a national cross-sectional survey in Belgium.
OBJECTIVE
Folic acid deficiency during pregnancy can lead to neural tube defects (NTD) in the fetus. Folate status was determined in a representative sample of Belgian pregnant women and determinants of folate status were assessed.


METHODS
The women were selected using a multi-stage proportionate-to-size sampling design. Blood samples were collected and a questionnaire was completed face-to-face with a study nurse. Erythrocyte (red blood cell (RBC)) folate concentration was measured by chemoluminescence.


RESULTS
In total, 1311 pregnant women participated and women with a lower socio-economic status were well represented. Median RBC folate concentration was 436 ng/ml (95% confidence interval=425-452 ng/ml) among first trimester and 496 ng/ml (95% confidence interval=474-515 ng/ml) among third trimester women. Few women had a RBC folate concentration below 140 ng/ml, indicating depletion of folate stores. In the first trimester, 39% of women had a RBC concentration below 400 ng/ml, whereas 15% of the first trimester women had a RBC concentration below 300 ng/ml. Among women in the first trimester, 69.1% reported taking folic acid-containing supplements of which 41.2% started taking them before pregnancy. For third trimester women, these percentages were 76.2% and 21.9%, respectively. In both trimesters, folate status increased significantly with education level and was significantly higher among women who planned the pregnancy and who did not smoke.


CONCLUSIONS
It was found that 39% of the first trimester pregnant women had a folate status that might not be optimal to prevent NTD. Some groups of women need to be targeted as they are at higher risk of inadequate folate status.
Department of Public Health and Surveillance, Scientific Institute of Public Health, Brussels, Belgium.
S
S
Vandevijvere
S
S
Amsalkhir
H
H
Van Oyen
R
R
Moreno-Reyes
D000293:Adolescent; D000328:Adult; D001530:Belgium / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004032:Diet / Q000009:adverse effects*; D019587:Dietary Supplements; D004522:Educational Status; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000097:blood / Q000627:therapeutic use; D005494:Folic Acid Deficiency / Q000097:blood / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D006306:Health Surveys; D006801:Humans; D008875:Middle Aged; D009436:Neural Tube Defects / Q000453:epidemiology / Q000517:prevention & control; D009752:Nutritional Status; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D012306:Risk; D012907:Smoking / Q000009:adverse effects; D055815:Young Adult
D005492:Folic Acid