Senior study author Lolkje T.W. de Jong-van den Berg commented:
"These findings provide further evidence to avoid valproic acid, if possible, in pregnant women and [for doctors] to discuss with girls and women of childbearing potential the risk of the drug for the unborn child."2
Dr. Kimford Meador, a professor of neurology at Emory University in Atlanta, commented:
"This drug should not be used as a first-line drug for epilepsy in women of childbearing age. There are multiple types of malformations that can be associated with valproic acid."2
Summary and comments:
When looking at the percentages by which the risk of birth defects is increased, it's important to note that those percentages are what are called "relative risks." For example: Spina bifida occurs in sever out of 10,000 births in the general population of the United States. That's a rate of .0007%, making the rate of spina bifida in children born to mothers who had used valproic acid during the first trimester of pregnancy .0089%. The chances of having a baby with any of the birth defects listed above when valproic acid was taken during the first trimester was less than 1%, or less that one in 100. Even viewed in that perspective, the study clearly shows that taking valproic acid during pregnancy poses significant risks to the unborn child.
The FDA has classified valproic acid as pregnancy category D. That means that studies, adequate well-controlled or observational, in pregnant women have demonstrated a risk to the fetus. However, the benefits of therapy may outweigh the potential risk.
If you could become pregnant and are taking valproic acid, the time to talk with your doctor about potential birth defects is now, now after you become pregnant.
1 Jentink, Janneke, M.Sc.; Loane, Maria A., M.Sc.; Dolk, Helen, Dr. P.H.; Barisic, Ingeborg, Dr. P.H.; Garne, Ester, M.D.l Morris, Joan K., Ph.D.; de Jong-van den Berg, Lolkje T.W., Ph.D. "Valproic Acid Monotherapy in Pregnancy and Major Congenital Malformations." N Engl J Med 2010;362:2185-93.
2 Goodwin, Jennifer. "Epilepsy Drug Linked to Serious Birth Defects." HealthScout.com. June 9, 2010.
Medical review by John Claude Krusz, PhD, MD