True statement regarding use of antiepileptic drugs in pregnancy

Neural tube defects are associated with valproate. fetal anticonvulsant syndrome or fetal hydantoin syndrome :risk is increased with the number of drugs.the cause is thought to be folate defeciency as these drugs interfere with folate metabolism monotherapy is associated with lower risk TEXTBOOK OF GYNECOLOGY,SHEILA BALAKRISHNAN,Pg no:330,2nd edition