Hi,does prenatal multivitamins prevents birth defects cause by lamictal.i don't know which medication is best lamictal or keppra during pregnancy?

Lamictal and Keppra work via different methods. Both can cause problems in pregnancy. Your Dr and you need to determine whether the need for the stabilizing effects of this medication outweigh the risks. Studies have shown that taking folic acid (present in hier quantities in prenatal vitamins) can help if you are taking Keppra.

Although both Lamictal and Keppra are Category C drugs, studies of pregnant women on Lamictal have shown very low incidence of fetal malformations. Similar extensive studies of Keppra are not available to my knowledge. Adding prenatal vitamins and folic acid is always wise when taking anti-epileptic meds. Would advise against switching medication unless efficacy or side effects problematic.