Data Highlights | References | Tables

Background

Neural tube defects (NTDs), which include spina bifida (open spine) and anencephaly (open skull), are among the most common birth defects that contribute to perinatal mortality, infant mortality, and serious disability in surviving children.^1,2 NTDs affect an estimated 3,000 pregnancies annually.¹ Just under one-third (approximately 850) of NTD-affected pregnancies are terminated spontaneously or electively, and approximately 2,200 pregnancies result in the birth of an infant with an NTD.¹ Among children born with an NTD, 95% are born to couples with no family history of these birth defects. Women who have had an NTD-affected pregnancy have a 2%–3% risk for a recurrence in subsequent pregnancies.²

Research indicates that consumption of folic acid, a B vitamin, before conception and during the first trimester can reduce the occurrence of NTDs by 50%–70%.^1,3–7 Given the effectiveness of folic acid in preventing NTDs, the U.S. Public Health Service (PHS) and the Food and Nutrition Board of the Institute of Medicine have separately recommended that all women capable of becoming pregnant consume 0.4 milligrams (mg) of folic acid daily.^8,9 Because more than half of all pregnancies in the United States are unplanned and NTDs occur during the first 4 weeks of pregnancy (4–6 weeks after the first day of a woman's last menstrual period), before many women even realize they are pregnant, this recommendation applies to all women capable of becoming pregnant—not just to women who are currently pregnant or planning to become pregnant.^2,10

The 1992 PHS recommendation identified three potential approaches for delivering folic acid in the dosage recommended: consuming foods rich in naturally occurring folates, using dietary supplements containing folic acid, and fortifying food.¹¹ Following the Food and Drug Administration (FDA)-mandated fortification of cereal grain products with folic acid that began in January 1998,¹² the occurrence of NTDs declined 27%, from an annual average of 4,130 cases in 1995–1996 to 3,020 cases in 1999–2000.¹

Despite efforts to increase folic acid intake through fortification, not all women obtain adequate levels of folic acid through their diets.³ Therefore, the PHS recommends that women who could become pregnant take daily multivitamins, which generally contain the recommended daily allowance of 0.4 mg of folic acid.^9,13 According to data from national telephone surveys conducted by the Gallup Organization for the March of Dimes Birth Defects Foundation, the use of multivitamins with folic acid increased slightly from 32% in 2003 to 33% in 2005.³ Nonwhite, young, less-educated, and low-income women were the least likely to report daily use of a vitamin containing folic acid.³

In 2000, 25%–41% of women in 19 PRAMS states reported taking a multivitamin 4 or more times per week in the month prior to pregnancy.¹⁴ In all 19 states, women with 12 or fewer years of education were significantly less likely than women with more than 12 years of education to report using multivitamins before pregnancy. Reported use of multivitamins also increased with maternal age. Additionally, in 11 states, reported multivitamin use was significantly higher among white/other race women than among black women, while in 10 states, reported use among non-Hispanic women was significantly higher than use by Hispanic women.¹⁴

PRAMS collects data on multivitamin consumption (4 or more times per week) in the month prior to pregnancy. States can use PRAMS data to promote multivitamin use among populations where folic acid consumption is lower than recommended. States can also use PRAMS data to monitor their progress in achieving the Healthy People 2010 objective (Objective 16–16a) of increasing the proportion of nonpregnant women aged 15–44 years who consume at least 0.4 mg of folic acid per day from fortified foods or supplements from 21% (1991–1994) to 80%.¹⁵

Data Highlights

• In 2002, the prevalence of multivitamin use (4 or more times per week) in the month prior to pregnancy ranged from 24.8% (Oklahoma) to 41.8% (North Dakota).
  
  
• During 2000–2002, the prevalence of multivitamin use in the month prior to pregnancy increased in 3 states (Illinois, North Carolina, and Utah).

References

1. Centers for Disease Control and Prevention. Spina bifida and anencephaly before and after folic acid mandate—United States, 1995–1996 and 1999–2000. MMWR 2004;53(17):362–365.
   
   
2. American Academy of Pediatrics. Folic acid for the prevention of neural tube defects. Pediatrics 1999;104(2):325–327.
   
   
3. Centers for Disease Control and Prevention. Use of dietary supplements containing folic acid among women of childbearing age—United States, 2005. MMWR 2005;54(38):955–958.
   
   
4. Moore LL, Bradlee ML, Singer MR, Rothman KJ, Milunsky A. Folate intake and the risk of neural tube defects: an estimation of dose-response. Epidemiology 2003;14(2):200–205.
   
   
5. Lumley J, Watson L, Watson M, Bower C. Periconceptional supplementation with folate and/or multivitamins for preventing neural tube defects. The Cochrane Database of Systematic Reviews 2001;(3). CD001056.
   
   
6. Locksmith GJ, Duff P. Preventing neural tube defects: the importance of periconceptional folic acid supplements. Obstetrics and Gynecology 1998;91(6):1027–1034.
   
   
7. Medical Research Council (MRC) Vitamin Study Research Group. Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. Lancet 1991;338(8760):131–137.
   
   
8. Institute of Medicine (IOM). Dietary Reference Intake: Folate, Other B Vitamins, and Choline. Washington, DC: National Academy Press; 1998.
   
   
9. Centers for Disease Control and Prevention. Recommendations for the use of folic acid to reduce the number of cases of spina bifida and other neural tube defects. MMWR Recommendations and Reports 1992;41(RR-14):1–7.
   
   
10. Centers for Disease Control and Prevention National Center on Birth Defects and Developmental Disabilities (Web site). Folic Acid Professional Resources: Recommendations. October 31, 2003. Available at http://www.cdc.gov/ncbddd/folicacid/health_recomm.htm.
    
    
11. Centers for Disease Control and Prevention. Folic acid and prevention of spina bifida and anencephaly: ten years after the U.S. Public Health Service Recommendation. MMWR Recommendations and Reports 2002;51(RR-13):1–3.
    
    
12. U.S. Department of Health and Human Services Food and Drug Administration. Food standards: amendment of the standards of identity for enriched grain products to require addition of folic acid. Federal Register 1996;(61):8781–8797.
    
    
13. Moss AJ, Levy AS, Kim I, Park YK. Use of vitamin and mineral supplements in the United States: current users, types of products, and nutrients. Advance Data From Vital and Health Statistics. Hyattsville, MD: National Center for Health Statistics; 1989.
    
    
14. Williams LM, Morrow B, Lansky A, Beck LF, Barfield W, Helms K, et al. Surveillance for selected maternal behaviors and experiences before, during, and after pregnancy. Pregnancy Risk Assessment Monitoring System (PRAMS), 2000. MMWR Surveillance Summaries 2003;52(SS-11):1–14.
    
    
15. U.S. Department of Health and Human Services. Healthy People 2010: Understanding and Improving Health. 2nd Edition. Washington, DC: U.S. Government Printing Office; 2000.

 

Prevalence of Multivitamin Use 4 or More Times per Week During the Month Prior to Pregnancy, 2002

State	Respondents	Percent†	Standard Error	95% CI‡
Alabama	1,561	25.7	1.3	23.1–28.4
Alaska	1,615	31.6	1.4	29.0–34.3
Arkansas	1,956	26.5	1.4	23.9–29.4
Colorado	2,288	38.3	1.3	35.8–40.9
Florida	2,016	30.4	1.6	27.4–33.6
Hawaii	1,818	34.4	1.4	31.8–37.1
Illinois	1,928	40.4	1.2	38.0–42.7
Louisiana	1,699	27.5	1.2	25.2–29.9
Maine	1,134	37.7	1.6	34.6–40.9
Maryland	1,454	35.3	1.8	31.8–39.0
Michigan	1,540	35.1	1.4	32.4–37.8
Minnesotaa	1,147	36.9	1.8	33.4–40.5
Montana	1,044	36.5	1.5	33.6–39.5
Nebraska	1,883	36.8	1.4	34.2–39.5
New Jerseyb	946	38.5	1.8	35.0–42.1
New Mexico	1,561	28.9	1.2	26.6–31.3
New Yorkc	1,225	37.9	1.7	34.5–41.3
North Carolina	1,542	35.2	1.5	32.3–38.2
North Dakota	906	41.8	1.6	38.7–45.0
Ohio	1,372	32.8	1.6	29.6–36.1
Oklahoma	1,868	24.8	1.6	21.9–28.0
Rhode Island	1,408	40.3	1.5	37.4–43.4
South Carolina	1,409	33.9	2.0	30.1–38.0
Utah	1,571	38.6	1.6	35.6–41.7
Vermont	1,103	40.8	1.5	38.0–43.7
Washington	1,516	37.2	1.8	33.7–40.7
West Virginia	1,692	25.2	1.5	22.4–28.3
All PRAMS states§	41,202	34.3	0.4	33.6–35.1
† 2002 state range is 24.8–41.8%. ‡ Confidence interval. § Aggregate of the 27 PRAMS states. a Data represent Minnesota births from May–December 2002. b Data represent New Jersey births from July–December 2002. c Data exclude New York City.

 

Prevalence of Multivitamin Use 4 or More Times per Week During the Month Prior to Pregnancy, 2002

Healthy People 2010 Objective 16–16a Increase the proportion of nonpregnant women aged 15–44 years who consume at least 0.4 mg of folic acid each day from fortified foods or dietary supplements to at least 80%.

 

Prevalence of Multivitamin Use 4 or More Times per Week During the Month Prior to Pregnancy, 2000–2002

State	2000 (%)	2001 (%)	2002 (%)	P value for trend#
Alabama	25.9	26.4	25.7	0.918
Alaska	30.9	32.0	31.6	0.701
Arkansas	25.3	24.1	26.5	0.555
Colorado	35.3	34.2	38.3	0.100
Florida	28.6	31.5	30.4	0.422
Hawaii	35.9	32.4	34.4	0.379
Illinois	33.5	34.9	40.4	0.000**
Louisiana	29.7	28.1	27.5	0.190
Maine	40.7	42.3	37.7	0.205
Maryland	—	36.7d	35.3	# #
Michigan	—	33.8e	35.1	# #
Minnesota	—	—	36.9a	# #
Montana	—	—	36.5	# #
Nebraska	34.1	35.2	36.8	0.141
New Jersey	—	—	38.5b	# #
New Mexico	28.5	28.0	28.9	0.807
New Yorkc	35.5	37.3	37.9	0.339
North Carolina	29.6	32.3	35.2	0.006*
North Dakota	—	—	41.8	# #
Ohio	34.7	34.4	32.8	0.407
Oklahoma	25.0	27.8	24.8	0.000**
Rhode Island	—	—	40.3	# #
South Carolina	32.7	30.3	33.9	0.654
Utah	31.3	35.6	38.6	0.001**
Vermont	—f	42.5f	40.8	# #
Washington	35.1	35.0	37.2	0.399
West Virginia	25.0	27.5	25.2	0.882
# Based on a test for linear trend using logistic regression. * p value is less than 0.05. ** p value is less than 0.001. # # < 3 years of data available; test for linear trend not applicable. a Data represent Minnesota births from May–December 2002. b Data represent New Jersey births from July–December 2002. c Data exclude New York City. d Data represent Maryland births from February–December 2001. e Data represent Michigan births from July–December 2001. f Data represent Vermont births from October 2000–December 2001.