PREVENZIONE, DIAGNOSI E TRATTAMENTO DELLA ALLOIMMUNIZZAZIONE RH IN GRAVIDANZA

Before the introduction of anti-D immune globulin, hemolytic disease of the fetus and newborn affected 9-10% of pregnancies and was a major cause of perinatal morbidity and mortality. Among rh D-alloimmunized pregnancies, mild to moderate hemolytic anemia and hyperbilirubinemia occur in 25-30% of fetuses/neonates, and hydrops fetalis occurs in another 255 of such cases. The administration od anti-D immune globulin is successful in reducing the rate of developing antibodies to the D antigen. Protocols for the antenatal and postpartum administration of anti-D immune globulin have been responsible for the dramatic decrease in alloimmunization and subsequent hemolytic disease in the past two decades. However, Rh D alloimmunization remains a clinical concern, with many cases due to failure to follow established protocols. Measurements of the peak velocity of blood flow in the middle cerebral artery in fetuses at risk for anemia due to maternal red-cell alloimmunization provide an accurate and noninvasive means of determining the degree of anemia. More than 70% of invasive testing can be avoided using this modality to monitor alloimmunized pregnancies. Intrauterine intravascular transfusion is extremely effective in treating fetal red blood cell alloimmunization. Fetal intravascular transfusions allow survival of more than 90% of fetuses with severe hemolytic disease due to red blood cell alloimmunization.