Chimerism Following Fetal Transfusion

Abstract

The clinical outcome from 461 Rh‐sensitized pregnancies whose infants received fetal and/or neonatal blood transfusion have been observed over a period of 7 years. 23 of 124 (19.5 %) infants receiving intrauterine transfusion showed persistence of donor white blood cells at birth. 34 of 82 (41.5 %) peripheral blood samples taken one day following exchange transfusion of the neonate displayed metaphase figures of donor cells. Donor cells could be identified in only 15 of 57 (26.3 %) of these infants on the day of hospital discharge. At four months of age, only one infant maintained a donor cell line which subsequently disappeared at one year of age. In contrast, 5 of 65 infants surviving fetal transfusion have consistently demonstrated the persistence of circulating donor white cells beyond one year of age. One of these infants has developed acute lymphocytic leukaemia at 4 1/2 years of age, and one of these presumably chimeric children demonstrated hybrid cells in its peripheral blood. No evidence of morbid conditions relating to the transfusion(s) have been noted in the infants who received transfusions only after birth.