Rates of selected birth defects in relation to folic acid fortification, Hawaii, 1986-2002

Because of studies suggesting that folic acid use reduces risk of various birth defects, the Unites States fortified enriched cereal grains with folic acid in 1998. To determine whether this fortification reduced rates for birth defects in Hawaii, rates were calculated before and after fortification. Of the 19 birth defects categories studied, the rates for 16 were lower after fortification.