Key Findings: Folic acid use among pregnant women who have had a past pregnancy affected by a neural tube defect

CDC’s Morbidity and Mortality Weekly Report has published a new study looking at folic acid use before pregnancy in women who have had a previous pregnancy affected by a neural tube defect (NTD). CDC researchers found that among a group of pregnant women who had a previous pregnancy affected by an NTD, women with another pregnancy affected by an NTD reported taking folic acid less often (35%) than those who had a baby without a birth defect (80%). This is important information for healthcare providers and health departments because many women who have had a pregnancy affected by an NTD and are planning a next pregnancy may not be following folic acid recommendations. You can read the article here.

Main Findings

  • This study looked at women who had a previous pregnancy affected by an NTD. During their next pregnancy, women who had their subsequent pregnancy affected by an NTD were less likely to have taken folic acid (35% took folic acid) compared with women who had a subsequent baby without a birth defect (80% took folic acid).
  • More than one third of the mothers who had a second pregnancy affected by an NTD were Hispanic.
  • Healthcare providers and health departments should strengthen their messages to encourage folic acid use among women with a previous pregnancy affected by an NTD who are planning another pregnancy.

About this Study

  • Researchers used data from the National Birth Defects Prevention Study for the years 1997-2009. They looked at mothers who had a previous pregnancy affected by an NTD and explored maternal characteristics for those who did and those who did not have another pregnancy affected by an NTD.
  • Researchers studied a number of factors about mothers including:
    • Type of NTD (anencephaly, spina bifida, and encephalocele) that occurred in her previous affected pregnancy
    • Folic acid supplement use in the 3 months before pregnancy
    • Race/ethnicity
    • Body mass index (BMI)
    • Prescription medication use
    • Pregnancy intention (whether a woman had planned the pregnancy)

Neural Tube Defects: CDC activities

CDC is working to address neural tube defects with the following activities:

Basics about NTD Recurrence
  • NTD recurrence is when a woman who already had a pregnancy affected by an NTD has another pregnancy affected by an NTD.
  • Women with a previous pregnancy affected by an NTD are more likely to have another pregnancy affected by an NTD.
  • Taking high-dose folic acid before another pregnancy reduces this risk.
  • If these women are planning another pregnancy, CDC recommends they consume high-dose folic acid (4.0 mg) beginning at least 4 weeks before becoming pregnant and continuing through the first 12 weeks of pregnancy1.
  • High-dose folic acid supplements require a prescription by a healthcare provider.

More Information

To learn more about folic acid, please visit

https://www.cdc.gov/ncbddd/folicacid/index.html

Key Findings Reference

CDC. Supplement Use and Other Characteristics among Pregnant Women with a Previous Pregnancy Affected by a Neural Tube Defect—United States, 1997-2009. MMWR Morb Mortal Wkly Rep. 2015: 64(01);6-9.

Additional References
  1. CDC. Use of folic acid for prevention of spina bifida and other neural tube defects–1983-1991. MMWR Morb Mortal Wkly Rep 1991;40:513-6.
  2. Boulet SL, Yang Q, Mai C, et al. Trends in the postfortification prevalence of spina bifida and anencephaly in the United States. Birth Defects Res A Clin Mol Teratol. 2008;82(7):527-32.
  3. CDC. Racial/ethnic differences in the birth prevalence of spina bifida – United States, 1995-2005. MMWR Morb Mortal Wkly Rep. 2009;57(53):1409-13.
  4. CDC. Folate status in women of childbearing age, by race/ethnicity – United States, 1999-2000. MMWR Morb Mortal Wkly Rep. 2002;51(36):808-10.
  5. CDC. Are women with recent live births aware of the benefits of folic acid? MMWR Morb Mortal Wkly Rep. 2001;50(RR06):3-14.
  6. Pfeiffer CM, Hughes JP, Lacher DA, et al. Estimation of trends in serum and RBC folate in the U.S. population from pre- to postfortification using assay-adjusted data from the NHANES 1988-2010. J Nutr. 2012;142(5):886-93.
  7. Hamner HC, Mulinare J, Cogswell ME, et al. Predicted contribution of folic acid fortification of corn masa flour to the usual folic acid intake for the US population: National Health and Nutrition Examination Survey 2001-2004. Am J Clin Nutr. 2009;89(1):305-15.
  8. Hamner HC, Tinker SC, Flores AL, Mulinare J, Weakland AP, and Dowling NF. Modelling fortification of corn masa flour with folic acid and the potential impact on Mexican-American women with lower acculturation. Public Health Nutr. 2013;16(5):912-21.