Hemolytic disease of the fetus and newborn

Abstract

Hemolytic disease of the fetus and newborn (HDFN) is a condition that results in varying degrees of hyperbilirubinemia and anemia. The diseases that produce this condition are broadly categorized as isoimmune (antibody mediated) or non-isoimmune. While Rh isoimmunization has historically been the most common diagnosis associated with HDFN, the appropriate use of Rh immunoglobulin (RhIG) during pregnancy and just after delivery has made it much less likely. Prenatal screening tests including maternal blood type, Rh status, and antibody screen can help to identify fetuses at risk for this disorder and therefore qualify for additional monitoring with middle cerebral artery peak systolic velocity (MCA-PSV) using ultrasound techniques. In severe cases, a fetus can receive intrauterine transfusions to treat anemia and prevent hydrops fetalis. After birth, neonates should be monitored for rapidly rising bilirubin or progressive anemia. Selected investigation may include a blood type, direct antiglobulin test (DAT), complete blood count, reticulocyte count, G6PD testing, and albumin measurement. The American Academy of Pediatrics (AAP) has provided a gestational age and hour of life-specific nomograms to guide treatment using both phototherapy and double volume exchange transfusion (DVET). In isoimmune hemolytic disease, infants may also benefit from IVIG treatment. In the most severe cases, a DVET is performed using reconstituted whole blood to replace twice the infant’s blood volume. There are risks associated with this procedure and may need to be performed more than once before anemia and hyperbilirubinemia are controlled.