RISK FACTORS: Prior transfusion with incompatible blood, Any Rh-positive pregnancy in Rh-negative woman, Without prophylactic immunotherapy (Rh immune globulin), risk of Rh sensitization is up to 16% during or after term pregnancy
APPROPRIATE HEALTH CARE :
. Affected pregnancies usually managed at the tertiary care level because of the specialized, somewhat
hazardous treatment measures involved
. Delivery should occur in an institution capable of performing exchange transfusion even if only mild
involvement of infant is expected
. Infants with moderate or severe disease require neonatal intensive care
GENERAL MEASURES :
. Depending on severity of involvement, treatment of infant may include:
. Phototherapy
. Transfusion after delivery
. Exchange transfusion
. Diuretics and digoxin for hydrops
. Early delivery
. Intrauterine transfusion. Intravascular approach via the umbilical vein is becoming preferred over the
intraperitoneal approach and appears to be more effective.
ALTERNATIVE DRUGS :
β’ Diuretics, inotropic agents, etc., may be used in addition to transfusion to manage heart failure in the
newborn
β’ Promethazine, immune serum globulin, corticosteroids, and plasmapheresis have been tried as alternatives to
invasive treatments but have not been effective
PATIENT MONITORING :
β’ Antibody titer measured every few weeks during pregnancy. A titer of 1:16 or greater indicates need for
further testing.
β’ Periodic amniocentesis for photometric determination of amniotic fluid bilirubin levels in pregnancies with
elevated antibody titers. Results estimate the extent of fetal hemolysis and the need for cord blood sampling.
β’ Percutaneous umbilical blood sampling (PUBS, cordocentesis) for fetal blood type, hematocrit, reticulocyte
count, presence of erythroblasts
β’ Fetal heart rate testing/ultrasonography to assess fetal status
β’ Amniocentesis for fetal lung maturity
PREVENTION/AVOIDANCE :
β’ Rho(D) Immune Globulin (RhIG, RhoGAM, Gamulin Rh) given prophylactically to unsensitized, Rh-negative
pregnant women at risk. Usually at 28-32 weeks gestation and at birth if infant is Rh positive (see Rh
incompatibility topic).
β’ Artificial insemination with sperm from antigen-negative donor for isoimmunized woman whose partner is
antigen positive
POSSIBLE COMPLICATIONS :
β’ Fetal distress requiring emergent delivery
β’ Fetal death in utero
β’ Disseminated intravascular coagulation (DIC)
β’ Pregnancy loss from umbilical blood sampling
β’ Pregnancy loss from intrauterine transfusion
β’ Asphyxia
β’ Neonatal hemolytic anemia, mild to severe
β’ Neonatal anemia from hematopoietic suppression after intrauterine transfusion
β’ Pulmonary edema
β’ Congestive heart failure
β’ Shock
β’ Neonatal jaundice, mild to severe
β’ Kernicterus
EXPECTED COURSE/PROGNOSIS :
β’ 50% of affected infants have mild disease and require no treatment (or treatment of anemia and jaundice only after delivery), and can be delivered at or near term
β’ 30% have moderate disease with anemia and hepatomegaly. They require close followup of the pregnancy
for signs of deterioration which may require early delivery after 32-34 weeks or intrauterine transfusion prior to that age. After delivery exchange transfusion is likely to treat anemia and hyperbilirubinemia.
β’ 20% have fetal hydrops, require intrauterine transfusion and delivery as early as 32-34 weeks
β’ Disease severity tends to worsen in successive affected pregnancies
β’ Hydrops is associated with poorer prognosis
β’ Without treatment overall perinatal mortality is 30%
β’ With appropriate monitoring and treatment most infants do well, even those requiring intrauterine transfusion
β’ Fortunately, with universal screening for Rh sensitization and widespread use of Rh immune globulin in 3rd
trimester and/or birth have made disease relatively rare