Hi Jill-
Congratulations on the pregnancy! You have twins? Twins are great (I'm a twin too!). When I found out I was pregnant with my first baby, I was on mysoline and my doctor took me off that in a hurry. It's a class D and I had at least 3 ultrasounds to make sure the baby didn't have a birth defect from the drug. Luckily, the baby was healthy.
Since my menses seemed to trigger my seizures in the first place, my ob and I decided not to substitute another antiseizure drug for the rest of the pregnancy and while I nursed the baby. The thought of starting a new drug while going through my first pregnany was traumatic. If the seizures returned, I would just resume another medication. Again, Luckily, everything went fine. I had a close working relationship with my doctor and it made all the difference in the world. My pediatrician was super too.
For me, if I was on a class C at the time I found out I was pregnant, I think I definitely would have stayed on it. It would have been less complicated and without the worries I went thru. Bottom line... I was glad my doctors were there for me every step of the way). Hope you have an uncomplicated pregnancy!
Take good care of yourself, Hugs, Glenda 