Several drugs often prescribed to pregnant women are being linked to serious birth defects.
The concern is with two medications. They were created to control epileptic seizures.
But the drugs, Valproic Acid and Topamax are also prescribed for other conditions, including migraines, pain, and bipolar disorder.
A newly published study following more than a million pregnant women found the risk of Spina Bifida was 19 times higher among women taking Valproic acid early in their pregnancy.
Topiramate, sold under the brand name Topamax, increased the risks of cleft lip and palate when taken in early pregnancy.
About two percent of pregnant women take an anti-seizure drug, and that number is rising because the medications help with those other conditions.
None of the other anti-seizure medications - lamotrigine, levetiracetam, carbamazepine, oxcarbazepine and gabapentin - were linked to birth defects.
The American Epilepsy Society says the effects had been seen in earlier studies, but were reinforced in the new one.
Two epilepsy drugs linked to birth defects, study says