[Kell alloimmunization in pregnancy]

Abstract

Introduction: Kell alloimmunization is a rare disease, although its incidence is the highest after after anti-D alloimmunization.

Methods: We report two recent cases and a review of the literature to describe practical management of Kell alloimmunization in pregnancy.

Discussion: When an immunization against the Kell antigen was diagnosed, amniocentesis was performed at 14 weeks gestation to determine the fetal blood group. If the fetus was Kell positive, a first fetal blood sample was drawn at 17 weeks gestation in case of fetal hydrops, and at 20 weeks without fetal hydrops. The diagnosis of anemia led to in utero transfusion. A second fetal blood sample was taken at 8 to 10 days, every two weeks during the second trimester and every three or four weeks during the third trimester. Fetal well-being was assessed with weekly sonography and rates of hemoglobin decline. These measures enable adapting the frequency of fetal blood sampling.