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Prevention Program for Reducing Risk for Neural Tube Defects -- South Carolina, 1992-1994

Neural tube defects (NTDs) are common and serious malformations that originate early in pregnancy. In the United States, approximately 4000 pregnancies each year are affected by the two most common NTDs (spina bifida and anencephaly), and an estimated 2500 infants are born with NTDs. Based on a Public Health Service (PHS) recommendation published in September 1992, at least one half of NTDs could be prevented if all women capable of becoming pregnant consumed 0.4 mg of folic acid daily during the periconceptional period (1). Women who have previously had an NTD-affected pregnancy would especially benefit from folic acid supplements (2). In 1992, with support from a CDC cooperative agreement, the South Carolina Department of Disabilities and Special Needs implemented a prevention program to reduce the incidence of folic acid-preventable NTDs in the pregnancies of women with prior NTD-affected pregnancies. This report describes surveillance findings resulting from this program during 1992-1994.

In October 1992, the NTD prevention program initiated a pilot surveillance system to monitor the occurrence of NTDs in the Piedmont Region of the state (1990 population: 1.1 million). Data about NTD cases were collected from hospital medical records, vital records, and prenatal diagnoses procedure records. In October 1993, the surveillance system was expanded statewide (1990 population: 3.5 million). During October 1992-September 1994, the surveillance system identified 105 NTD cases and 72,493 live-born infants, representing a rate of 14.5 cases per 10,000 resident live-born infants.

Of the 105 women identified as having had NTD-affected pregnancies, 71 participated in a personal interview about use of folic acid-containing supplements during the periconceptional period (i.e., 1 month before conception through the third month of pregnancy). Overall, six (8%) of the 71 women reported using a folic acid-containing multivitamin supplement during the periconceptional period, including four (7%) of the 54 women who had a last menstrual period after the PHS recommendation was issued, and two (12%) of the 17 women who had a last menstrual period before the PHS recommendation was issued. Reported by: RE Stevenson, MD, JH Dean, WP Allen, MD, Greenwood Genetic Center, Greenwood; M Kelly, South Carolina Dept of Disabilities and Special Needs, Columbia. Birth Defects and Genetic Diseases Br, Div of Birth Defects and Developmental Disabilities, National Center for Environmental Health, CDC.

Editorial Note

Editorial Note: During 1980-1990, an estimated 18,000 infants were born in the United States with spina bifida; by 1990, approximately 5000 (28%) of these children had died. Annual medical and surgical costs in the United States for all persons with spina bifida exceed $200 million. For each person with typical severe spina bifida, the estimated lifetime direct and indirect costs are $250,000 (3).

In 1992, PHS estimated that, if all women capable of becoming pregnant adhered to the recommendation to consume 0.4 mg of folic acid per day, the number of cases of spina bifida and anencephaly would be reduced by 50%. Consumption of a vitamin supplement containing the prescribed amount of folic acid is one method to ensure receipt of the proper dosage of folic acid. In 1992, an estimated 20% of all U.S. women were consuming a multivitamin containing 0.4 mg of folic acid (4). However, the findings in this report indicate that, among women with NTD-affected pregnancies in South Carolina who had conceived after issuance of the PHS recommendation, only 7% had consumed 0.4 mg of folic acid during the periconceptional period. In addition, among a sample of 60 women in South Carolina who had given birth to infants without NTDs during October 1992-September 1994, seven (12%) reported using folic acid-containing vitamin supplements during the periconceptional period (Greenwood Genetic Center, Greenwood, South Carolina, unpublished data, 1994). These findings suggest that overall use of folic acid-containing supplements in South Carolina is lower than the 1992 PHS estimate of use among the total population of U.S. women (4).

The findings in this report underscore the need for increased efforts in South Carolina to 1) publicize the benefits and promote the use of increased folic acid consumption during the periconceptional period, 2) encourage women of childbearing age to increase their folic acid consumption, and 3) ensure that all women have the opportunity to increase their consumption of folic acid. Since promulgation of the 1992 PHS recommendation, public and private health-care and advocacy organizations in South Carolina have initiated information and education campaigns to promote consumption of folic acid among women of childbearing age. In addition, educational programs have been designed and implemented to communicate information about the protective benefits of folic acid to health professionals, public school educators, and the public.


  1. CDC. Recommendations for the use of folic acid to reduce the number of cases of spina bifida and other neural tube defects. MMWR 1992;41(no. RR-14).

  2. MRC Vitamin Study Research Group. Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. Lancet 1991;338:131-7.

  3. CDC. Economic burden of spina bifida -- United States, 1980-1990. MMWR 1989;38:264-7.

  4. Moss AJ, Levy AS, Kim I, et al. Use of vitamin and mineral supplements in the United States: current users, types of products, and nutrients. Hyattsville, Maryland: US Department of Health and Human Services, Public Health Service, CDC, NCHS, 1989. (Advance data no. 174).

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