Management of thrombotic microangiopathy in pregnancy and postpartum: report from an international working group.

Abstract

Pregnancy and postpartum are high-risk periods for different forms of thrombotic microangiopathy (TMA). However, the management of pregnancy-associated TMA remains ill-defined. This report by an international multidisciplinary (obstetricians, nephrologists, hematologists, intensivists, neonatologists and complement biologists) working group summarizes the current knowledge of these potentially severe disorders and proposes a practical clinical approach to diagnose and manage an episode of pregnancy-associated TMA. This approach takes into account the timing of TMA in pregnancy or postpartum, co-existing symptoms, first-line laboratory work-up and probability-based assessment of possible causes of pregnancy-associated TMA. Its aims are to urgently rule in or out thrombotic thrombocytopenic purpura (TTP) with ADAMTS13 activity testing, to consider alternative disorders with features of TMA (preeclampsia/eclampsia, Hemolysis Elevated Liver enzymes Low Platelets (HELLP) syndrome, antiphospholipid syndrome (APS)) or ultimately to diagnose complement-mediated atypical hemolytic uremic syndrome (aHUS) as a diagnosis of exclusion. Even though rare, it is paramount to diagnose TTP and aHUS associated with pregnancy and postpartum, as both require urgent specific treatment.