Toxic damages in fetuses and newborns rank highly in perinatal pathology structure, though their true importance is not understood thoroughly. Among toxic encephalopathies of newborns the accent should be given to the conditions caused by administration of medicines by a pregnant woman. The use of medicines, especially neurotropic, during pregnancy is often forced. The widespread prevalence of epilepsy in women of reproductive age leads, in certain cases, to anticonvulsants administration during pregnancy. The dominance of valproic acid in epilepsy treatment in recent decades requires studying its teratogenic effect in newborns fetal valproate syndrome. The fetal valproate syndrome has casuistic nature and polymorphic phenomenology.
 The clinical case study is presented of a newborn with fetal valproate syndrome (born to a mother who took valproic acid in dose 14 mg/kg per day or 750 mg per day while pregnant, due to Janz syndrome), confirmed by valproic acid presence in the blood of a newborn (47.36 mol/l), with the main clinical manifestation of incomplete cleft palate (hard and soft) without other typical disturbances.
 Most anticonvulsants have a teratogenic effect, and may cause malformations and toxic encephalopathies in fetus and newborns. The similarity of clinical manifestations of intrauterine exposure to various anticonvulsants is associated with the presence of common metabolic links (epoxy and dihydrodiol derivatives of phenytoin, phenobarbital and carbamazepine). In spite of similarity of some teratogenic effect mechanisms, the anticonvulsants nature introduces specific clinical manifestations of these disorders.