Is it safe to take sabril while pregnant or breastfeeding?

Depends on situation. As a category c drug it causes some problems in animal studies during fetal development but none in existing human studies. In breastfeeding, little is expected to cross into the milk but monitoring for sleepiness, or poor sucking has been suggested.
Probably not. Sabril is a category c anticonvulsant. Birth defects have been noted in animals. And it does enter breastmilk. However, if epilepsy is a major problem, the benefits of taking an anticonvulsant for the mother usually outweigh the theoretical risk to the fetus.