Clinical Significance

The purpose of the Kleihauer Betke test is to identify fetal red cells in the presence of adult red cells to determine feto-maternal bleed. This can be done for Rh positive mothers where trauma needs to be confirmed or, more typically, for Rh negative mothers.

The passage of red cells from an Rh positive fetus into the circulation of an Rh negative mother results in the formation of specific Rh antibodies. In subsequent pregnancies, the Rh antibodies formed in the blood serum of the Rh negative mother are readily transmissible through the placenta into the circulation of the fetus. The action of the antibodies on the Rh positive cells of the fetus may result in a disease recognized as erythoblastosis.

Rh negative mothers who have been exposed to the Rh factor as a consequence of transfusion with Rh positive blood from the fetus are administered specific gamma globulin containing anti-Rho (D) to suppress the immune reaction. The amount of gamma globulin administered is calculated by assessing the magnitude of fetal/maternal hemmorhage.

_{Source: Sure-Tech Fetal Hemoglobin IFU. Procedure No. 101 Rev. 10/2017}