Hydrops Fetalis due to Kell Alloimmunization: A Perinatal Approach to a Rare Case

While routine administration of rhesus (Rh) immunoglobulin has significantly reduced the incidence of Rh alloimmunization, maternal alloimmunization to other red cell antigens remains a contributor to perinatal morbidity and mortality. Although the Kell antigen is seen on the red cells of only 9% of the general population, attention to Kell antibodies continues to increase.

A case of fetal hydrops was sonographically detected at 30 weeks of gestation. Antenatal tests to evaluate the fetus's condition clearly showed that the level of hemolytic disease was critical and the baby was delivered prematurely due to fetal distress. The combination of anemia, reticulocytopenia, hydrops fetalis, and a positive indirect Coombs test suggested Kell isoimmunization. The baby was successfully treated with exchange transfusion of Kellnegative packed red cells, and was discharged on postnatal d 30.

The presented case of hydrops fetalis was due Kell alloimmunization that was detected during the postnatal period, and thus we plan to discuss the perinatal approach to Kell immunization.