Topamax is the brand name of Topiramate, an anticonvulsant drug prescribed for the control of epileptic seizures in children and adults. A secondary use is the prevention of migraines.
The FDA has announced that women who use Topamax while they are pregnant are at an increased risk of giving birth to babies with a cleft lip and/or cleft palate. Healthcare providers are recommended to discuss alternative treatment options with pregnant women using Topamax. Women taking topiramate should immediately discuss the matter with their physicians if they are planning to or become pregnant, because oral clefts develop early in pregnancy, before many women even know they are pregnant.
No patient, even if they are pregnant, should stop taking the drug unless told to do so by their physician.
The FDA safety announcement can be found here.