International retrospective cohort study of neural tube defects in relation to folic acid recommendations: are the recommendations working?
OBJECTIVE
To evaluate the effectiveness of policies and recommendations on folic acid aimed at reducing the occurrence of neural tube defects.


METHODS
Retrospective cohort study of births monitored by birth defect registries.


METHODS
13 birth defects registries monitoring rates of neural tube defects from 1988 to 1998 in Norway, Finland, Northern Netherlands, England and Wales, Ireland, France (Paris, Strasbourg, and Central East), Hungary, Italy (Emilia Romagna and Campania), Portugal, and Israel. Cases of neural tube defects were ascertained among liveborn infants, stillbirths, and pregnancy terminations (where legal). Policies and recommendations were ascertained by interview and literature review.


METHODS
Incidences and trends in rates of neural tube defects before and after 1992 (the year of the first recommendations) and before and after the year of local recommendations (when applicable).


RESULTS
The issuing of recommendations on folic acid was followed by no detectable improvement in the trends of incidence of neural tube defects.


CONCLUSIONS
Recommendations alone did not seem to influence trends in neural tube defects up to six years after the confirmation of the effectiveness of folic acid in clinical trials. New cases of neural tube defects preventable by folic acid continue to accumulate. A reasonable strategy would be to quickly integrate food fortification with fuller implementation of recommendations on supplements.
Botto
Lorenzo D
LD
National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. icbd@icbd.org
Lisi
Alessandra
A
Robert-Gnansia
Elisabeth
E
Erickson
J David
JD
Vollset
Stein Emil
SE
Mastroiacovo
Pierpaolo
P
Botting
Beverley
B
Cocchi
Guido
G
de Vigan
Catherine
C
de Walle
Hermien
H
Feijoo
Maria
M
Irgens
Lorentz M
LM
McDonnell
Bob
B
Merlob
Paul
P
Ritvanen
Annukka
A
Scarano
Gioacchino
G
Siffel
Csaba
C
Metneki
Julia
J
Stoll
Claude
C
Smithells
Richard
R
Goujard
Janine
J
D000028:Abortion, Induced / Q000706:statistics & numerical data; D015331:Cohort Studies; D019587:Dietary Supplements; D005060:Europe / Q000453:epidemiology; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007557:Israel / Q000453:epidemiology; D009436:Neural Tube Defects / Q000453:epidemiology / Q000517:prevention & control*; D016742:Preconception Care; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D012042:Registries; D012189:Retrospective Studies
D005492:Folic Acid
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