Pathological findings in hydrops foetalis due to alpha-thalassaemia: A review of 32 cases

Pathological changes observed in 32 cases of hydrops foetalis due to α-thalassaemia with a large amount of Hb “Bart's” are described. All infants were Chinese (12 male and 20 female) and were stillborn or died soon after birth. Delivery occurred between 28 and 38 weeks of pregnancy, often with complications, and was usually associated with symptoms of maternal toxaemia. Of 2 pairs of twins, 1 pair was uniovular and both infants were hydropic. The other pair was binovular, 1 infant being hydropic and 1 normal. Two hydropic siblings were born a year apart from the same mother. Changes in the blood, as reported in previous papers, were typical. The placentas were large, friable and oedematous. Most foetuses were grossly hydropic and pale, with greatly distended abdomens due to ascites and liver enlargement, but the spleens were not always enlarged. The histological changes, except those in the blood, closely resembled changes accompanying hydrops foetalis due to iso-immunization. When sickling was observed in histological slides, it facilitated differentiation between the two conditions. The most important and constant findings were excessive extramedullary erythropoiesis and oedema in various organs. Persistence of Langhans cells and prominent Hofbauer cells in the placenta, enlargement of the islets of Langerhans in the pancreas, and enlargement of and changes in the adrenal glands resembled findings for hydrops foeralis due to iso-immunization.