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

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.