The March of Dimes has been campaigning for nearly 10 years for increased folic acid fortification of basic foods like flour and bread, and now they say why. (I'm sure they said why before, too; it's not like MOD is the Knights Templar or anything. Right? Right?) It helps drastically reduce neural tube defects (NTD) like spina bifida and anencephaly, which often occur in the earliest weeks of pregnancy.
People with uteruses can also get folic acid from vegetables and multivitamins, and people with uteruses, insurance and a hankerin' to use them can get it from pre-natal multivitamins, which are as big as your fist.
New research shows folic acid in grains has reduced birth defects [marchofdimes, via robotwisdom]