A young woman with a transfusion-related pregnancy complication

Individuals with the K0 phenotype are extremely rare. They may develop anti-Ku antibodies, which react with all antigens of the Kell blood group system, thereby leading to haemolytic transfusion reactions and haemolytic disease of the fetus and newborn.

A primigravida who was transfused with one unit of red blood cells due to iron deficiency anaemia developed anti-Ku antibodies. The pregnancy was closely monitored by ultrasound and antibody titres. Maternal autologous blood collection was performed twice during the last trimester as back-up in case of maternal peripartum bleeding, and a few frozen K0 red blood cell units were provided in case of severe fetal anaemia. At gestational week 36+6, labour was induced due to increasing antibody titres and high blood velocities in the fetal middle cerebral artery during systole. The woman was delivered vaginally without need for transfusion. The infant was diagnosed with haemolytic disease of the fetus and newborn and treated with phototherapy, repeated infusions of intravenous immunoglobulin and iron supplements until normalisation of haemoglobin at three months of age.

Iron deficiency anaemia should be treated primarily with iron supplementation before considering blood transfusions, which pose the risk of developing alloantibodies that can cause transfusion complications and haemolytic disease of the fetus and newborn.