The Food and Drug Administration said new data shows expecting mothers taking the drug, sold generically and as Johnson & Johnson's Topamax, are about 20 times more likely to have their infants develop cleft lips or cleft palate deformities than those who are not treated.
Officials called on doctors to warn their female patients of childbearing age who are taking the medicine about its risks since the defects occur in the first three months of pregnancy, before women may know they are expecting.
Cleft lips and cleft palates
can occur when the mouth does not fully form, causing a "split lip" or a hole in the roof of the mouth.
The conditions can lead to multiple development issues because they can make it nearly impossible for babies to get adequate nutrition. They can be corrected with surgery, although sometimes several operations are needed.
In a statement, J&J said Topamax's label already notes the risks with pregnancy and "recommended cautious use in pregnant patients." It said it would work with the FDA to clarify the drug's use during pregnancy.