Thirty-eight cases of haemolytic disease of the newborn.

Thirty of the 38 cases were the result of Rh sensitization, and eight were due to incompatibility in the ABO system. Prenatal Investptions. Pregnant women attending the health centres, which combine the functions of prenatal and infant welfare clinics, were examined routinely for Rh blood groups. The Rh-negative women were tested for Rh antibodies. Cases with Rh antibodies were invited to attend for monthly control titrations during the second trimester, and twice a week during the last trimester of pregnancy. In a similar way serial antibody determinations for anti-A or anti-B were carried out during pregnancy in all cases with a previous history of isoimmunization and erythroblastotic infants due to ABO incompatibility. The blood group and Rh type of the father's red cells were also determined in all cases of suspected iso-immunization. Rh antibodies in maternal sera were examined in saline and plasma. In the second part of this study the Coombs indirect method was also used. In several instances trypsinized cells were examined (Morton and Pickles, 1947). Neonatal Investations. Cord blood was studied in those cases in which the past history of the mother or the laboratory studies during pregnancy suggested the possibility of haemolytic disease of the newborn infant. In all cases not preceded by prenatal examinations the infant's venous blood was tested immediately following the first appearance of signs of haemolytic disease. The examinations included blood group and Rh type deteEminations, the direct Coombs test and a blood count. Method of Treatment. In previous years cases of erythroblastosis foetalis have been treated by simple transfusions-single or multiple-of Rh-negative blood, or of group 0-blood in instances due to ABO incompatibility. Since 1950 exchange transfusion has been carried out in all cases in which the previous history and the clinical and laboratory findings suggested the possibility of a severe form of haemolytic disease in the newborn infant. For exchange transfusion, generally, the technique as recommended by Diamond (1947) and Mollison, Mourant and Race (1948) was used. A plastic catheter was introduced into the umbilical vein and the blood was exchanged by the 20 ml.-out 20 ml.-in method. If more than 12 hours had elapsed after birth the vena cava was entered through the saphena magna vein in the groin and the femoral vein according to the technique described by Arnold and Alford (1948). In two instances, owing to the technical difficulties, the umbilical route had to be abandoned for the withdrawal of blood. The remainder of the blood was withdrawn from the sagittal sinus through the anterior fontanelle. In general, from 400 to 500 ml. of donor blood was used for replacement, leaving a surplus of about 50 ml. of transfused blood above the amount of withdrawn blood.