Microangiopathic Hemolytic Anemia of Pregnancy: Facts and Figures

Microangiopathic hemolytic anemia (MAHA) of pregnancy is a rare but severe pregnancy complication that is characterized by nonimmune intravascular hemolysis or destruction of red blood cells and the formation of small blood clots in the capillaries and small blood vessels of the body (microangiopathy) resulting in a wide variety of symptoms, some of which include weariness, weakness, shortness of breath, jaundice, and edema. This condition affects both the mother and the developing fetus. The primary aim is to differentiate primary thrombotic microangiopathy from other systemic illnesses that can present with microangiopathic hemolytic anemia (MAHA) and thrombocytopenia. We desire glorious motherhood and a healthy baby (George and Nester, N Engl J Med 371:654, 2014; Narayanan et al., Int J Hematol 96:122–124, 2012). MAHA of pregnancy is often associated with other pregnancy-related conditions, such as preeclampsia, HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count), and pregnancy-associated TMA, especially thrombotic thrombocytopenic purpura (TTP) and complement-mediated hemolytic uremic syndrome (CM HUS). These conditions can cause similar symptoms and can be life-threatening if not promptly diagnosed and treated. Although there is clinical overlap, management varies significantly. MAHA is caused by RBC fragmentation as they pass over platelet-rich thrombi in microcirculation. Thrombotic microangiopathies define small vessel changes, including endothelial cell swelling, vessel wall thickening, and platelet thrombi formation in the microvasculature. These changes obliterate the vessel lumen or microaneurysm, affecting the blood flow and resulting in single or multi-end-organ damage. MAHA in conjugation with thrombosis throughout microcirculation and consumptive thrombocytopenia occurs clinically in TMA. The goal is to limit irreversible end-organ damage.