Birth defects in Arkansas: is folic acid fortification making a difference?
BACKGROUND
Since 1998, fortification of grain products with folic acid has been mandated in the United States, in an effort to reduce the prevalence of neural tube defects (NTDs). Published reports have shown a reduction in the prevalence of spina bifida since fortification was mandated, but no published studies have reported a reduction in birth defects, other than NTDs, that are postulated to be associated with folic acid deficiency. This study was performed to determine if fortification has reduced the prevalence of NTDs and other birth defects in Arkansas.


METHODS
Using data from the Arkansas Reproductive Health Monitoring System, prevalences were computed for thirteen specific birth defects with prior evidence supporting a protective effect of folic acid or multivitamins. Prevalences were calculated using data for live births to Arkansas residents for 1993-2000. Exposure to folic acid fortification was classified by birth year as "pre-fortification" (1993-1995), "transition" (1996-1998) or "post-fortification" (1999-2000). Logistic regression analysis was used to compute crude and adjusted prevalence odds ratios comparing the identified time periods.


RESULTS
Prevalences decreased between the pre- and post-fortification periods for spina bifida, orofacial clefts, limb reduction defects, omphalocele, and Down syndrome, but only the decrease in spina bifida was statistically significant (prevalence odds ratio 0.56; 95% confidence interval, 0.37, 0.83).


CONCLUSIONS
In Arkansas, the prevalence of spina bifida has decreased since folic acid fortification of foods was implemented. Similar studies by other birth defects surveillance systems are needed to confirm a preventive effect of fortification for malformations other than spina bifida.
Simmons
Caroline J
CJ
Arkansas Center for Birth Defects Research and Prevention, College of Medicine, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock 72211, USA.
Mosley
Bridget S
BS
Fulton-Bond
Cynthia A
CA
Hobbs
Charlotte A
CA
D000328:Adult; D001741:Black or African American; D001131:Arkansas / Q000453:epidemiology; D002675:Child, Preschool; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage*; D005527:Food, Fortified; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009436:Neural Tube Defects / Q000453:epidemiology* / Q000517:prevention & control*; D011247:Pregnancy; D015995:Prevalence; D044465:White People
D005492:Folic Acid