Valproic acid

Authors

  • Edward J. Lammer,

    1. Division of Birth Defects and Developmental Disabilities, Center for Environmental Health, Centers for Disease Control, Public Health Service, U.S. Department of Health and Human Services, Atlanta, Georgia 30333
    Search for more papers by this author
  • Lowell E. Sever,

    1. Division of Birth Defects and Developmental Disabilities, Center for Environmental Health, Centers for Disease Control, Public Health Service, U.S. Department of Health and Human Services, Atlanta, Georgia 30333
    Search for more papers by this author
  • Godfrey P. Oakley Jr.

    1. Division of Birth Defects and Developmental Disabilities, Center for Environmental Health, Centers for Disease Control, Public Health Service, U.S. Department of Health and Human Services, Atlanta, Georgia 30333
    Search for more papers by this author

Abstract

Valproic acid use during pregnancy results in an absolute risk for spina bifida of 1–2%. This increased risk is comparable to the recurrence risk for neural tube defects and warrants informed counselling and access to prenatal diagnosis. There is no substantial evidence that valproic acid use increases the risk for other specific major malformations above the increased risk due to maternal epilepsy. Valproic acid may cause a characteristic pattern of minor facial malformations. Further definition and confirmation are required, and the magnitude of the risk needs to be determined. There are inadequate data to assess the magnitude, if any, of the risks for postnatal growth abnormalities and developmental disabilities associated with the use of valproic acid during pregnancy. Birth-defect monitoring programs and international collaboration among the staffs of monitoring programs played a major role in determining that valproic acid is a human teratogen.

Ancillary