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Clinical Summary

Folic Acid for the Prevention of Neural Tube Defects: Preventive Medication

Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.

Population Women who are planning or capable of pregnancy
Recommendation Take a daily supplement containing 0.4 to 0.8 mg (400 to 800 µg) of folic acid.
Grade: A
Risk Assessment All women of childbearing age are at risk of having a pregnancy affected by neural tube defects. Some factors increase this risk, including a personal or family history of neural tube defects, use of particular antiseizure medications, maternal diabetes, obesity, and mutations in folate-related enzymes.
Preventive Medication Folic acid is the synthetic form of folate, a water-soluble B vitamin. Folic acid is usually given as a multivitamin, prenatal vitamin, or single supplement, and is also used to fortify cereal grain products. Folate occurs naturally in foods such as dark green leafy vegetables, legumes, and oranges. However, most women do not receive the recommended daily intake of folate from diet alone.
Timing The critical period for supplementation starts at least 1 month before conception and continues through the first 2 to 3 months of pregnancy.
Dosage Supplementation with a multivitamin containing 0.4 to 0.8 mg (400 to 800 µg) of folic acid decreases the risk of neural tube defects.
Balance of Benefits and Harms The USPSTF concludes with high certainty that the net benefit of daily folic acid supplementation to prevent neural tube defects in the developing fetus is substantial for women who are planning or capable of pregnancy.

For a summary of the evidence systematically reviewed in making this recommendation, the full recommendation statement, and supporting documents, please go to

Current as of: January 2017

Internet Citation: Clinical Summary: Folic Acid for the Prevention of Neural Tube Defects: Preventive Medication. U.S. Preventive Services Task Force. January 2017.

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