Immunization to Rho(D) Observed in Pregnancy of a Woman with Type rhG(G)

A Negro woman was tested during her third pregnancy and found to have type rhG(G). When the patient was re‐tested during the sixth month of her fourth pregnancy, she was found to have a weak antibody of questionable identity. During the last two months of the pregnancy, the titer of the antibody rose sharply and it was established to be specific for Rho(D). The infant, delivered by cesarean section shortly before term, had evidence of mild hemolytic disease; it recovered without transfusion therapy. Since this indicates that isoimmunization to Rho can occur in a person of type rhG, such persons should receive only Rho‐negative blood for transfusion. They should be regarded as Rh‐negative for prenatal purposes, but it might be considered preferable not to use them as blood donors for Rh‐negative recipients.