American College of Preventive Medicine public policy statement. Folic acid fortification of grain products in the U.S. to prevent neural tube defects.

Neural tube defects (NTD), specifically spina bifida and anencephaly, affect approximately 4,000 live births and pregnancies each year in the United States.1 Of these, the Centers for Disease Control and Prevention (CDC) report that 1500 infants are born with spina bifida, 1000 are born with anencephaly, and an estimated 1500 fetuses are aborted annually.2 NTDs are implicated in 1.3% of all infant deaths and are second only to cardiac defects as the leading cause of perinatal mortality from all birth defects.3 These spinal cord malformations are associated with serious developmental disabilities including muscle weakness and/or paralysis, bowel and bladder incontinence, and intellectual impairment. While infants with anencephaly usually die shortly after birth, those with spina bifida usually survive into adulthood. The combined lifetime medical and indirect costs for a survivor with spina bifida are estimated to be $350,000.4 For all those affected, the total annual economic burden is in excess of $480 million.5 Certain maternal factors are associated with an increased risk of neural tube defects, including previous history of NTD-affected pregnancy (20–30-fold elevation in risk), genetic defects in folate metabolism, and reduced periconceptional intake of folic acid. The incidence of NTDs has decreased since the 1930s (5 per 1000 to less than 5 per 10,000 live births).6 This has been attributed to prenatal diagnosis with selective pregnancy termination and nutritional factors. Inadequate dietary intake of folic acid has been implicated as a substantive, if not primary, cause of NTDs.7 The CDC estimates that 50%–70% of NTDs could be prevented if women consumed at least 400 micrograms of folic acid daily.7 Unfortunately, recent nutritional surveys demonstrate that, on average, U.S. women of childbearing age consume only about half of the 400 micrograms of folate recommended.8 In a 1997 March of Dimes Birth Defects Foundation, survey only 66% of women reported ever hearing about folic acid; only 16% reported knowledge that it helps reduce birth defects; and only 9% reported knowledge that it should be taken before pregnancy.2 Overall, as few as 30% of non-pregnant women of childbearing age reported taking a vitamin supplement containing folic acid.2 Because adequate folic acid levels are required during the first 28 to 30 days of gestation—prior to closure of the neural tube—it is often too late to begin vitamin supplementation once pregnancy is confirmed. Furthermore, in the U.S., about half of all pregnancies are unplanned and many women remain unaware of their pregnancies for several weeks.9