Detection of Trace Amounts of Fetal RhD-Positive Red Cells with Flow Cytometry after Multiple Rh-Negative Intrauterine Transfusions and RhD-Gene Determination with PCR

Abstract

In 2 cases of RhD-sensitized women, hemolytic disease of the newborns (hdn) was mitigated by intrauterine transfusions of·Rh-negative donor blood during pregnancy. In both cases preterm delivery was performed by cesarean section in week 32 of pregnancy. With cord blood the direct antiglobulin test (DAT) was negative using the gel test. The blood groups corresponded to the transfused donor blood. With flow cytometry (FC), 2% of IgG-coated red cells were found in the cord blood in case I and 5% in case 2. Using FC, these cells were RhD positive. Polymerase chain reaction (PCR) analyses showed the presence of RhD-gene sequences in both cases. Therefore, FC and PCR seem to be suitable methods for the diagnosis and the monitoring in cases of imminent hemolytic disease due to anti-D alloimmunization. With further transfusions, both children developed well after delivery.