Hemolytic diseases of the newborn is a condition in which red blood cells of a newborn infant or a perinatal fetus are destroyed prematurely resulting in anemia. It's also known as erythroblastosis fetalis
Specifically, HDN occurs when the blood types of mother and baby are incompatible ,like in the case of an Rh-negative mother having no D-antigen, Carrie's an Rh-positive fetus with D-antigen. Incompatibility happens when the baby has an antigen that the mother does not have. The mothers immune system interprets the antigen as "foreign" and produce antibodies to target the cells carrying it for destruction.
The first mismatch pregnancy usually not at risk, because the placenta separating the mother's blood from the fetal blood. However at birth or if a miscarriage or abortion occurs , the tearing of the placenta exposes fetal blood to the mother who then responds by producing antibodies against the fetus. If the mother is again pregnant with Rh-positive fetus, her antibodies being small enough to cross the placenta can now cause haemolysis.
Mothers can be sensitized during :
- Blood transfusion
Signs and symptoms :
- anaemia => heart failure, respiratory distress,
- jaundice ( bilirubin) => brain damage
Infants born with HDN develops jaundice due to the destruction of haemoglobin , bilirubin starts to accumulate in the body. The rapid destruction of red blood cells making the body unable to excrete bilirubin effectively, its levels rise quickly within 24h of birth. Bilirubin is toxic for brain tissue and may cause reversible brain damage in a condition known as kernicterus.
Anti-D immunoglobulin ( Anti-D Ig )
Haemolytic disease of the newborn can now be effectively prevented. Anti-D Ig is given to Rh-negative mothers during and soon after the first mismatch pregnancy. This antibody binds to the fetal blood cells that leak into the mothers blood, either destroying them, or hiding them from the mothers immune system.
- intravenous fluid
- phototherapy => a procedure in which a certain
spectrum of light is used to convert bilirubin to
a form that is easier for the infant to excrete.
- blood transfusion
- intravenous immunoglobulin G therapy : blocks
Destruction of red blood cells
- exchange transfusion ( replacing with Rh-
Negative donor blood )