THE PREVALENCE OF RED-CELL ANTIBODIES IN PREGNANCY CORRELATED TO THE OUTCOME OF THE NEWBORN - A 12 YEAR STUDY IN CENTRAL SWEDEN

Background. All maternal red cell antibodies found during pregnancy in a 12 year period have been compiled. The efficacy of the current antenatal screening and management programme has been ascertained by reviewing the outcome of all newborns to these immunized mothers. Method. Patient selection was carried out by computerised searching for all known records of registered antibodies during the study period. Each mother's obstetric record and her baby's hospital file was studied and relevant clinical treatment and laboratory data on both mother and child was recorded and analysed. Results. Eight hundred and twenty-one alloantibodies were detected in 629 immunized pregnant women with 753 fetuses. An overall antibody incidence of 0.57% was observed which included 373 clinically significant antibodies found in 261 mothers (0.24%). Multiple antibodies were present in 8.2% of all samples. Anti-D, by itself or in combination with other Rh-antibodies, caused more severe forms of hemolytic disease of the newborn (HDN) with 46% of all Ph-positive babies having phototherapy and 29% having exchange transfusion. Three of 18 Fy(a)-positive infants required phototherapy and one required exchange transfusion and in the 16 Kell-positive babies, three required phototherapy and one required exchange transfusions. Conclusions. Few antibodies to blood group antigens other than those in the Rhesus system were found to cause severe HDN. Antibodies that are generally considered non-significant did not cause HDN in this study. All antibodies that induced HDN were detected in time so that adequate measures could be taken to reduce the effects in the newborn. The antenatal screening and management programme currently in use is considered to be reliable.