Impact of folic acid fortification in the United States: markedly diminished high maternal serum alpha-fetoprotein values.
OBJECTIVE
Folic acid fortification of breads and grains was implemented in the United States in 1998 in an attempt to reduce the incidence of neural tube defects. Outcome data from birth registries have shown a 20% drop-less than originally predicted. In this study, we ascertain if the impact of folic acid fortification is better seen at the time of midtrimester prenatal diagnosis by looking at incidence of high maternal serum alpha-fetoprotein (MSAFP) values.


METHODS
Data regarding MSAFP levels in 61,119 patients undergoing maternal serum screening at a large commercial laboratory were categorized by multiples of the median (MoM). The data were compared between 2 groups: before mandatory supplementation in the United States in 1997 and after mandatory supplementation in 2000. High MSAFP values were further categorized as high (2.75-4.00 MoM) or very high (more than 4.00 MoM). Data were analyzed by chi(2) analysis.


RESULTS
Comparative data showed a 32% decrease of patients with MoM greater than 2.75 + (2.5% -1.7%). Further categorizations revealed similar decreases.


CONCLUSIONS
The introduction of folic acid fortification has produced a profound decrease in the number of high MSAFP values, reflective of a decreased incidence of neural tube defects. Our results help to validate the decision to fortify food with folic acid, which represents a highly successful public health policy for primary prevention of birth defects.


METHODS
II-2
Department of Obstetrics and Gynecology, Institute for Genetics and Fetal Medicine, St. Luke's Roosevelt Hospital Center, 1000 10th Avenue, Suite 11A, New York, NY 10019, USA. mevans@chpnet.org
Mark I
MI
Evans
Elisa
E
Llurba
Ellen J
EJ
Landsberger
Joseph E
JE
O'Brien
Harold H
HH
Harrison
D015331:Cohort Studies; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage*; D005527:Food, Fortified; D005865:Gestational Age; D006801:Humans; D009436:Neural Tube Defects / Q000175:diagnosis* / Q000517:prevention & control; D011247:Pregnancy / Q000097:blood*; D011296:Prenatal Diagnosis; D015397:Program Evaluation; D014481:United States / Q000453:epidemiology; D000509:alpha-Fetoproteins / Q000378:metabolism*
D000509:alpha-Fetoproteins; D005492:Folic Acid