Bilirubin values of cord blood in heterospecific pregnancy.

Following the discovery of the Rhesus factor by Landsteiner and Wiener (1940) and the demonstration by Levine, Burnham, Katzin, and Vogel (1941) that haemolytic disease of the newborn generally is the result of mother-child Rh incompatibility several reports of erythroblastosis foetalis attributable to sensitization of the mother by the A or B foetal antigens have been published, notably those of Boorman, Dodd, and Trinick (1949) and Mollison and Cutbush (1949a). In view of the hyperbilirubinaemia in cord blood which may be attained in cases of Rh sensitization, and the demonstration that erythroblastosis foetalis may occasionally result from mother-child ABO incompatibility, it was decided to examine the bilirubin level of cord blood to try to determine whether the ABO and Rh blood group systems exert any influence on this level in heterospecific pregnancies.