Study: Birth Defects Decline With Folic Acid

MINNEAPOLIS -- A certain type of birth defect has been reduced by 19 percent since the Food and Drug Administration authorized adding folic acid to grain products, according to a new study.

But researchers are not sure if the decrease is solely because of the folic acid fortification, according to an article in Wednesday's issue of The Journal of the American Medical Association.

Researchers from the National Center on Birth Defects and Developmental Disabilities in Atlanta studied 10 years' worth of birth certificate data for live births to women in 45 U.S. states and Washington, D.C., to evaluate the impact of food fortification with folic acid on neural tube birth defects.

Previous studies have found that folic acid supplements before conception and during the first trimester of pregnancy reduce the occurrence of two common neural tube defects (NTDs), spina bifida and anencephaly, which occur in about 4,000 pregnancies every year.

In 1992, the U.S. Public Health Service issued a recommendation that all reproductive-aged women who are capable of becoming pregnant should consume 400 micrograms of folic acid daily. A recent survey indicated that in 1998, only 29 percent of U.S. women were following the recommendation.

The Food and Drug Administration authorized the addition of folic acid to enriched grain products -- such as breads, pastas, rice, flour and cereals -- in March 1996, and made it a mandatory addition in January of 1998.

The researchers compared the number of NTDs reported on birth certificates before fortification (October 1995 through December 1996) to the number reported after mandatory fortification (October 1998 through December 1999).

The authors found that the occurrence of NTDs reported on birth certificates decreased from 37.8 per 100,000 live births before fortification to 30.5 per 100,000 live births conceived after mandatory folic acid fortification, representing a 19 percent decline.

During the same period, NTD birth prevalence for women who received only third-trimester or no prenatal care declined 13 percent.