Because women with paroxysmal nocturnal hemoglobinuria (PNH) are especially vulnerable to thromboembolic phenomena, pregnancy is a time of increased risk for both mother and fetus. However, pregnancies in affected women are rare; only case reports and small studies have been reported so far. We present the case of a 20-year-old woman with PNH who, while undergoing medical tests in preparation for a bone marrow transplant, was discovered to be pregnant. We also review the obstetric literature on pregnancy complicated by PNH, which indicates that both maternal and fetal mortality is exceptionally high (11.6% and 7.2%) with the major cause of maternal mortality being thromboembolism. Major maternal complications are more frequent postpartum (30.2%) than antepartum or intrapartum (16.3%).
Target audience: Obstetricians & Gynecologists, Family Physicians.
Learning objectives: After completion of this article, the reader should be able to recall that paroxysmal nocturnal hemoglobinuria (PNH) during pregnancy increases adverse events for both the mother and the fetus, state that maternal and fetal mortality are both high, and explain that the major complications occur in the postpartum period.