Most teratogenic in pregnancy: (A) Phenytoin, (B) Valproate, (C) Barbiturate, (D) Ethosuximide
Answer is B. Valproate is the most teratogenic, phenytoin also isn't safe. Phenobarbitone, lamotrigine, topiramate are relatively safe drugs but 4mg folic acid is required per day. Ref: KD Tripathi 8th ed.