Two consecutive pregnancies in a patient with paroxysmal nocturnal haemoglobinuria treated with anticoagulant therapy at different doses.

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare acquired disorder of haematopoietic stem cells characterized by intravascular haemolysis, cytopenias and thrombophilia. Thrombophilia is the leading cause of mortality in patients with PNH. As the risk of thrombogenesis further increases during pregnancy and the postpartum period, an anticoagulant therapy is generally recommended for pregnant women with PNH. However, there are no standardized criteria for determining the appropriate dose of anticoagulant therapy. We describe the case of a PNH patient with who was managed with anticoagulant therapy at different doses during two consecutive pregnancies. A prophylactic dose of heparin was administered during her first pregnancy and a therapeutic dose, during her second pregnancy. Both pregnancies resulted in uncomplicated vaginal deliveries without thrombosis. Interestingly, not only D-dimer (as a thrombotic marker) but also lactate dehydrogenase (as a haemolytic marker) levels were lower during her second pregnancy when a therapeutic dose of heparin was used.