I had been on Tegretol since I was 13.  I turned 28 when my new doc took me off of it.  I had 4 children while taking the tegretol and they are all healthy little girls.  I researched Keppra and Pregnancy.  I dont know why your doctor would want to change you to that if you decide to get pregnant!  It is a Class C drug!  FDA says it could do harm on a fetus.  No studies have been done on humans.  But it did cause harm on babies of animals. 

Hi,

I started taking Tegretol/carbamazepine in 1989 at the age of 13.  I have had two healthy children, and I stayed on Tegretol throughout both pregnancies.  My first child was born prematurely, at 35 1/2 weeks, which may or may not have been due to my Tegretol use.  She was 4lbs 15 oz, but healthy and came home two days later like a full term baby.  My second child was born at 38 weeks and was over 7 lbs.  My OB checked my Tegretol levels more often during my pregnancies in case the dosage needed to be adjusted.  Both times I was able to stay on my regular dose with no adjustments (and I gained 50 pounds with each pregnancy).  My OB always told me that she has had several patients on Tegretol during pregnancy with no problems.  I know that clinically it dose pose a higher rate of birth defects, however, so there is definitely cause to be careful and try to be on the lowest dosage necessary.

I hope that info helps put your mind at ease!