Thrombotic microangiopathy (TMA) associated with pregnancy: role of the clinical laboratory in differential diagnosis

Thrombotic microangiopathy (TMA) is characterized by thrombocytopenia, microangiopathic hemolytic anemia and target organ damage. Pregnancy is associated with several forms of TMA, including preeclampsia (PE), HELLP syndrome, thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). When HUS is secondary to a deregulation of the alternative complement pathway, it is known as atypical HUS (aHUS). Differential diagnosis is challenging, as these forms share clinical characteristics. However, early diagnosis is crucial for a specific treatment to be established and improve prognosis.