Management of paroxysmal nocturnal hemoglobinuria with low-level hemolysis in pregnancy– a report of two cases

Abstract Pregnant women with paroxysmal nocturnal hemoglobinuria (PNH) are at high risk for life-threatening thromboembolism. Therapy with the complement inhibitor eculizumab is able to mitigate thrombotic risks in PNH and to improve pregnancy outcomes. However, whether PNH with low-level hemolysis in pregnancy can be safely managed without complement inhibition is unclear. Here, we describe two pregnant patients with PNH in the setting of bone marrow failure and low-level hemolysis with lactate dehydrogenase (LDH) < 1.5 x upper limit of normal [ULN]. In both patients, management consisted solely of prophylactic anticoagulation, without the use of complement inhibition. Both pregnancies ended successfully without thromboembolic complications. We conclude that in pregnant patients with PNH and low-level hemolysis (i.e. LDH < 1.5 x ULN), management with close monitoring and prophylactic anticoagulation only, without use of complement inhibition, might be a reasonable strategy. More data to guide optimal management of pregnant women with PNH are needed.