The conundrum of thrombotic microangiopathy in pregnancy

Hypertensive disorders of pregnancy (HDP) including haemolysis, elevated liver enzymes and low platelet count (HELLP) and pre-eclampsia are one of the leading causes of maternal mortality. There is significant overlap between the acute clinical presentation of such HDP and other medical conditions with thrombotic microangiopathy such as acute fatty liver of pregnancy, catastrophic antiphospholipid antibody syndrome, acute systemic lupus erythematosus, atypical haemolytic uraemic syndrome and thrombocytopenic thrombotic purpura. This can make timely clinical diagnosis and treatment challenging. Here, we present a complex case of severe pre-eclampsia and HELLP with concerns for a thrombotic microangiopathy, where accurate clinical diagnosis of overlapping pathologies posed a clinical challenge, and share our key reflections and learning points in the context of current evidence. We discuss diagnostic tests to aid diagnosis and review the cardinal presenting features and pathophysiology of possible causes of thrombotic microangiopathy in pregnancy.