Rh(D) Alloimmunization

Prevention of Rh(D) alloimmunization in pregnancy Rh(D)-negative pregnant women Exposed to fetal D-positive red cells are at risk for developing anti-D antibodies. Widespread use of anti-D immunoglobulin has dramatically reduced, but not eliminated, D alloimmunization. www.uptodate.com/MusePath/contents/prevention-of-rhesus-d-alloimmunization-in-pregnancy?source=search_result&search=Rh(D)%20alloimmunization&selectedTitle=3~150

Prevention of Rh(D) alloimmunization in pregnancy Hemolytic disease of the fetus and newborn Severe form of anemia caused by the production of maternal antibodies against fetal red blood cells. Rhesus D (RhD), ABO, and less commonly other blood group antigen incompatibility between the fetus/infant and the mother can lead to the production of maternal antibodies (alloimmunization) when there is fetomaternal hemorrhage www.uptodate.com/MusePath/contents/prevention-of-rhesus-d-alloimmunization-in-pregnancy?source=search_result&search=Rh(D)%20alloimmunization&selectedTitle=3~150

Evaluation Screening First-time alloimmunized pregnancies Blood antigen typing for ABO and Rhesus D (RhD) groups and maternal Rh antibody At the first prenatal visit. First-time alloimmunized pregnancies Monitor every 4 weeks Increased risk for hemolytic anemia. Pregnancies in women that were previously Rh alloimmunized Increase the risk for hemolytic anemia in the infant. http://www.dynamed.com/topics/dmp~AN~T114634/Hemolytic-disease-of-the-fetus-and-newborn-HDFN

Management Pregnant Rh-negative women with a negative maternal Rh antibody screening result, indicating no prior anti-D alloimmunization, should have a repeat screening at 28 weeks to assess for alloimmunization if it is negative should receive 300 mcg Rh immune globulin intramuscularly, with consideration of a second dose if the fetus has not delivered by 40 weeks gestation positive maternal Rh antibody screening result, indicating an RhD sensitized pregnancy, require determination of maternal RhD antibody titers http://www.dynamed.com/topics/dmp~AN~T114634/Hemolytic-disease-of-the-fetus-and-newborn-HDFN

Prevention of Rh(D) alloimmunization in pregnancy Rh(D)-negative Pregnants whose fetus is/may Rh(D)-positive: Administration of anti-D immunoglobulin early in the third trimester 300 micrograms at 28 weeks of gestation 100 to 120 micrograms at 28 and 34 weeks

Management Management of Rh alloimmunized fetus may include: Intrauterine transfusion for fetal hematocrit ≤ 30% before 35 weeks gestation Testing for fetal lung maturity and amniotic bilirubin level Guide the decision as to when and if labor should be induced http://www.dynamed.com/topics/dmp~AN~T114634/Hemolytic-disease-of-the-fetus-and-newborn-HDFN

Prevention of Rh(D) alloimmunization in pregnancy Antenatal anti-D immunoglobulin 300 micrograms as soon as possible within 72 hours of the event Increased risk of fetomaternal hemorrhage ectopic pregnancy, miscarriage, abortion, multifetal reduction, amniocentesis, chorionic villus sampling, blunt abdominal trauma, external cephalic version, antepartum bleeding, and fetal death.

Prevention of Rh(D) alloimmunization in pregnancy Ongoing risk for fetomaternal hemorrhage Repeat dosing chronic placental abruption or placenta previa with intermittent vaginal bleeding Serial determinations of the maternal indirect Coombs every three weeks with repeat dosing if it is found to be negative.

Prevention of Rh(D) alloimmunization in pregnancy Anti-D immunoglobulin within 72 hours of delivery of an Rh(D)- positive infant 300 micrograms Additional doses Excessive fetomaternal hemorrhage If inadvertently omitted after delivery as soon as possible Partial protection is afforded with administration within 13 days of the birth May be an effect as late as 28 days after delivery

Prevention of Rh(D) alloimmunization in pregnancy Management of pregnancies complicated by alloimmunization intrauterine fetal transfusions Investigational maternal plasmapheresis intravenous immune globulin therapy