α-thalassemia-associated hydrops fetalis: A rare cause of thyrotoxic cardiomyopathy.

α°-thalassemia is a well-known cause of hydrops fetalis in South-East Asia and can be detected in utero. We report a very rare case of thyrotoxic cardiomyopathy associated with hyperplacentosis secondary to α°-thalassemia-associated hydrops fetalis. A 22-year-old primigravida with microcytic anemia presented at 27 weeks' gestation with pre-eclampsia, hyperthyroidism and cardiac failure. Serum β-human chorionic gonadotrophin was markedly elevated and abdominal ultrasound revealed severe hydropic features and enlarged placenta. Serum β-human chorionic gonadotrophin, cardiac function and thyroid function tests normalized after she delivered a macerated stillbirth. Histopathology of the placenta showed hyperplacentosis. Blood DNA analysis revealed that both patient and husband have the α°-thalassemia trait. This case illustrates a very atypical presentation of α°-thalassemia-associated hydrops fetalis and the importance of early prenatal diagnosis of α-thalassemia in women of relevant ethnic origin with microcytic anemia so that appropriate genetic counseling can be provided to reduce maternal morbidity and the incidence of hydrops fetalis.