Thrombotic microangiopathy is a syndrome characterized by microvascular embolism，which has acute onset，rapid progression，and a high mortality.Thrombotic microangiopathy rarely happens during pregnancy，so doctors are lack of awareness of this disease，which usually leads to missed diagnosis and misdisgnosis.This article summarizes the classification，pathogenesis，clinical manifestation，diagnostic criteria,differential diagnosis,therapy and prognosis of thrombotic microangiopathies.