Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic anemia in which a defect of glycophosphatidylinositol (GPI)-anchored proteins in the cell membrane of bone marrow stem cells leads to increased sensitivity of the red cells to complement, causing intravascular hemolysis and hemoglobinuria. Other clinical features of this disease are cytopenia and an increased frequency of thrombotic events. We report a case of a pregnant woman with PNH on high-dosage anticoagulation therapy, the follow-up during the pregnancy, the delivery and the postpartum period. The obstetric literature on women with PNH is reviewed, the maternal and fetal risks are evaluated and the management of pregnancies and deliveries in such patients are discussed. During the pregnancy our patient was hypertransfused and used anticoagulation treatment. A healthy child was delivered in week 37 by cesarean section because of premature rupture of the membranes, unsuccessful induction and intrauterine infection. Because of bleeding problems a hysterectomy also had to be performed. In the postpartum period the patient developed her second episode of a liver vein thrombosis. She recovered gradually and 18 months after the delivery her disease is now in a stable phase. The literature shows a high maternal morbidity and mortality among pregnant PNH patients. Fetal wastage and prematurity rate are also high. Pregnancy in patients with PNH represents a high-risk situation for both the mother and the child and should not be recommended. A pregnant PNH woman should be followed closely by both obstetricians and hematologists.