Lethal congenital dyserythropoietic anaemia type I in siblings presenting as pericardial effusions in the second trimester.

Congenital dyserythropoietic anaemias (CDA) are rare inherited disorders of erythropoiesis characterised by abnormal red cell morphology and haemolysis. The diagnosis of CDA should be considered in the fetus or patient presenting with a normocytic or macrocytic anaemia especially if red cell morphology is abnormal. Three types and other possible variants have been described. There are few reports of clinical presentation of CDA in utero. We present 2 cases of lethal CDA in siblings that presented with pericardial effusions in the second trimester.