Topics of discussion• What is Erythroblastosis Fetalis?• What is Rh incompatibility?• Signs of Rh incompatibility.• Diagnostic tools.• Prevention.• Treatment.
Definition Erythroblastosis Fetalis is a hemolyticanemia in the fetus or neonate, caused bytrans-placental transmission of maternalantibodies to fetal RBCs. The disorder usuallyresults from incompatibility between maternaland fetal blood groups, often Rh antigens.
Rh incompatibility• Mother Rh-Positive & fetus Rh-Negative.• RBCs from the fetus can go into the mother’s bloodstream through the placenta.• Rh-Negative mother’s immune system treats the Rh-Positive fetal cells as a foreign substance and makes antibodies against them.• These anti-Rh antibodies may cross the placenta into the fetus, where they destroy the fetus’s circulation red blood cells.
• First-born infants are often not affected unless the mother has had previous mis-carriages or abortions, which could have sensitized her system for developing antibodies.
SignsMother• Polyhydramnios in mother.Baby• Pallor ++• Hepatosplenomegaly – signifying active haemolysis• Jaundice MAY NOT be there at birth – since the mother’s kidney will take out the excess bilirubin – Jaundice develops in the next few hours of delivery
• Hypotonia• Mental retardation and hearing problems in the long term
• Polyhydramnios - Presence of excessive amniotic fluid surrounding the fetus.
Exams and Tests• A positive Coombs’ Test result – Direct and Indirect Coomb’s test• Fetal Blood Sampling ( FBS ) for Rh sensitization during pregnancy.• A high Level of bilirubin in the baby’s cord blood
Coombs’ Test: The Coombs’ test looks for antibodies that may bind to fetal blood cells and causes premature RBC destruction ( hemolysis).Indirect Coomb’s test (Mother)- for unbound circulating antibodies against red blood cells & used to determined if the person have a reaction to blood transfusion.Direct Coombs’ test (Baby) - to detect antibodies that are already bound to the surface of red blood cells in the baby.
• Fetal Blood Sampling ( FBS ) for Rh sensitization - Directly from the umbilical cord or fetus. - Tested for signs of anemia. - FBS is also known as cordocentesis or percutaneous umbilical cord blood sampling.
- FBS is used to look at a fetuss red bloodcell count and oxygen level, and it also looksfor signs that your immune system isdestroying fetal red blood cells.
• Rh immune globulin contains antibodies to the Rh factor in blood.• The antibodies come from mother’s blood stream had been sensitized to Rh factor.• Giving these Rh antibodies to an Rh-Negative pregnant woman prevent her immune system from producing its own anti-Rh antibodies, which would attack the Rh-Positive red blood cells of the fetus.
• Given to all Rh-Negative women who may be carrying an Rh-Positive fetus.• It cannot prevent damage to an Rh-Positive fetus if their mother is already sensitized to Rh factor.
• Rh immune globulin should be given to an Rh-negative woman to prevent sensitization :1. After amniocentesis, fetal blood sampling or CVS..2. When bleeding occurs in the second or third trimester of pregnancy.3. At 28 weeks of pregnancy.4. After an external cephalic version of a breech fetus.5. After abdominal trauma during pregnancy.6. Within 72 hours after delivery of an Rh-positive infant.7. After a threatened or complete miscarriage, or an induced abortion.8. Before or immediately after treatment for ectopic pregnancy or a partial molar pregnancy.
Treatment• Affected baby should be treated with: – Aggressive hydration – Early Phototherapy – Early Exchange transfusion if required • Removes Bilirubin • Removes antibodies • Removes sensitised cells which are liable to be haemolysed • Replaces the RBC numbers – haemolysed
• Antenatal Management – Mother’s titres Positivity / rise in titres – Giving Anti D to the mother – Amniotic fluid bilirubin levels (Lilleys charts) to look at early delivery – Foetal transfusion to prevent onset of severe anaemia and cardiac failure – Hydrops foetalis
• Fetal Blood Transfusion - Transfusions can be given through the fetal umbilical veinAn intrauterine transfusion provides blood to Rh- positive fetus when fetal red blood cells are being destroyed by Rh antibodies.A blood transfusion is given to replace fetal red blood cells that are being destroyed by the Rh- sensitized mothers immune system. This treatment meant to keep the fetus healthy until he or she is mature enough to be delivered .
• In a severely affected fetus, transfusions are done every 1 to 4 weeks until the fetus is mature enough to be delivered safely.• Amniocentesis may be done to determine the maturity of the fetuss lungs before delivery is scheduled.
• Hypotonia ( floppy infants ) - Decreased muscle tone. - Floppy & feels like a “rag doll” when held. - Their elbows and knees are loosely extended, while infants with normal tone tend to have flexed elbows and knees. - Head control may be poor or absent, with the head falling to the side, backward/forward,