Neural Tube Defects: Folic Acid Fortification Is Effective

Diana Phillips

January 17, 2015

The mandatory fortification of enriched cereal grain products has prevented the development of neural tube defects (NTDs) in approximately 1300 newborns per year, according to data published by the Centers for Disease Control and Prevention in the January 16 issue of the Morbidity and Mortality Weekly Report.

However, despite evidence supporting the preventive benefits of folic acid in pregnancy, both through fortification of grain products and dietary supplements, many women who have had a previous NTD-affected pregnancy do not take a folic acid supplement when planning a subsequent pregnancy, according to a separate report published in the same issue of the Morbidity and Mortality Weekly Report.

Together, the findings indicate that current fortification efforts are effective and should be maintained to reduce the birth prevalence of NTDs, but also that more targeted communication is needed to ensure that all women are aware of current folic acid recommendations, the authors of both studies conclude.

In the fortification report, Jennifer Williams, MSN, from the National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, and colleagues update previous birth prevalence data collected after the 1998 government mandate of folic acid fortification of enriched cereal grain products. For the new estimates, they reviewed data from 19 population-based birth defects surveillance programs in the United States covering a 12-year period (1999 - 2011).

"Immediately after mandatory fortification, the birth prevalence of NTD cases declined," the authors write, noting that fortification was estimated to avert approximately 1000 NTD-affected pregnancies annually. After the initial decrease, "NTD birth prevalence during the post-fortification period has remained relatively stable," they state. "The number of births occurring annually without NTDs that would otherwise have been affected is approximately 1,326."

When analyzed by racial/ethnic groups (non-Hispanic blacks, non-Hispanic whites, and Hispanics), the data show a reduction in the birth prevalence of NTDs for all three groups; however, "the prevalence among Hispanics is consistently greater than that among other racial/ethnic groups," the authors write, noting the possibility that this finding could be linked to dietary, genetic, or cultural differences.

Although mandatory folic acid fortification remains "an effective public health intervention," there remain opportunities for prevention among women with lower folic acid intakes, the authors write, "especially among Hispanic women, to further reduce the prevalence of NTDs in the United States."

In the second study, Annelise Arth, MPH, from the Division of Birth Defects and Developmental Disabilities, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, and colleagues evaluated folic acid supplement use among a convenience sample of women who participated in the case-control National Birth Defects Prevention Study, including 27 pregnant women with a previous NTD-affected pregnancy. Of the 27 women, 17 had a recurrent NTD-affected pregnancy and 10 had a second pregnancy that resulted in the live birth of a non-NTD-affected infant.

Of the 17 mothers in the recurrent NTD group, 35% reported taking a folic acid supplement compared with 80% of the mothers in the nonrecurrent group, the authors report. In addition, six of the 17 mothers in the recurrent group were Hispanic compared with only one of the mothers in the control group; in addition, six of the 17 mothers in the recurrent group were obese (prepregnancy obesity has been linked to NTD risk) compared with one of the control mothers.

"This study suggests that awareness of the importance of folic acid supplement use in preconception and early pregnancy should be increased among women with a previous NTD-affected pregnancy," the authors write. "Communication of the importance of this preventive action by health care providers to women of childbearing age, especially those at high risk for another NTD-affected pregnancy, should be improved," they stress.

The authors have disclosed no relevant financial relationships.

Morb Mortal Wkly Rep. 2015;64(1):1-5, 6-9. Williams full text, Arth full text

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....