USPSTF finalizes recommendation on daily folic acid intake to prevent neural tube defects

Key takeaways:

• One study found a reduced risk for neural tube defects when folic acid was used before and during pregnancy.
• The recommendation comes as folic acid deficiency remains a concern in the United States.

Individuals who are planning to or could become pregnant should take a daily folic acid supplementation of 0.4 to 0.8 mg to prevent neural tube defects, according to a final recommendation from the U.S. Preventive Services Task Force.

The A-grade recommendation, published in JAMA, aligns with the task force’s draft recommendation from February and its 2017 final recommendation.

“The task force continues to underscore the importance of taking a daily supplement containing folic acid before and during early pregnancy to help protect the health of babies,” USPSTF member Katrina Donahue, MD, MPH, said in a press release. “By taking folic acid, people can reduce the risk of developing neural tube defects, which can result in serious complications for babies including disability and death.”

According to the task force, neural tube defects can be caused by low levels of folate in the body and occur early in pregnancy, often before an individual knows they are pregnant.

The USPSTF noted there are several factors that could increase the risk for neural tube defects, which include obesity or diabetes, difficulty absorbing nutrients from food due to weight-loss surgery and having a family history of neural tube defects. Hispanic women are also at a higher risk, but the task force said it is unsure whether this is due to genetics or food preferences.

The recommendation is based on an evidence review conducted by Meera Viswanathan, PhD, an adjunct assistant professor at the University of North Carolina Gillings School of Global Public Health, and colleagues. The researchers examined 12 observational studies, three of which evaluated folic acid effects on neural tube defects. They reported that one cohort study found a significantly reduced risk for neural tube defects when folic acid supplementation was taken:

• before pregnancy (adjusted RR = 0.54; 95% CI, 0.31-0.91);
• during pregnancy (aRR = 0.62; 95% CI, 0.39-0.97); and
• before and during pregnancy (aRR = 0.49; 95% CI, 0.29-0.83).

However, of the study’s two time periods, from 1999 to 2005 and 2006 to 2013, the association was found only in the latter.

While the other studies found no significant benefits, no statistically significant harms — such as autism or maternal cancer — associated with pregnancy-related folic acid intake were identified either.

In a related editorial, David B. Nelson, MD, an associate professor in the department of obstetrics and gynecology at the University of Texas Southwestern Medical Center, and Catherine Y. Spong, MD, a professor at the same institution, wrote that folic acid deficiency is a concern in the United States, with only 20% to 40% of individuals recently pregnant or trying to become pregnant reportedly taking periconceptional folic acid from 1998 to 2016.

“Those with an unintended pregnancy were four to five times less likely to have taken periconceptional folic acid supplements,” they wrote. “Given that nearly half (45%) of the pregnancies in the U.S. are unintended, encouraging preconception health to promote improved knowledge and behaviors — including folic acid supplementation — are key to ensure that individuals entering pregnancy are in optimal health.”

Nelson and Spong noted that the recommendation on folic acid may seem “old” because it dates back nearly 3 decades, but “the synthesis of the current evidence by the USPSTF provides new assurances to both the benefit and lack of harm to patients.”

“This promotes not only the well-being of the individual but also the family, community, and society at large,” they wrote.

References:

• Nelson D, Spong C. JAMA. 2023;doi:10.1001/jama.2023.12972
• Task force issues final recommendation statement on folic acid supplementation to prevent neural tube defects. https://www.uspreventiveservicestaskforce.org/uspstf/sites/default/files/file/supporting_documents/folic-acid-suppl-final-rec-bulletin.pdf. Published Aug. 1, 2023. Accessed Aug. 1, 2023.
• Viswanathan M, et al. JAMA. 2023;doi:10.1001/jama.2023.9864.
• USPSTF. JAMA. 2023;doi:10.1001/jama.2023.12876