Rhesus Isoimmunization Flashcards
Mother’s Rh status?
Rh (-)
Fetal Rh status?
Rh (+)
What occurs with Rhesus Isoimmunization?
Mother produces antibodies to the fetal Rh D antigen and then they cross the placenta and destroy fetal RBCs
If a woman carries the Rh D antigen she is considered?
Rh (+)
What antibodies does the Rh (-) mother produce initially? What antibodies will cross the placenta?
IgM
IgG cross placenta
What leads to Isoimmunization?
Fetomaternal hemorrhage
– fetal blood enters maternal circulation
When does Isoimmunization occur most often?
Vaginal delivery
Any fetomaternal hemorrhage can cause Isoimmunization. What can prevent it?
RhoGAM
What is RhoGAM?
Anti-D immunoglobulin that decreases RhD in the maternal circulation so she does not make antibodies to it
What is RhoGAM?
Anti-D immunoglobulin that decreases RhD in maternal circulation so she does not make antibodies to it
When should RhoGAM be administered normally?
- 28 weeks
2. Within 72 hours after delivery
When should RhoGAM be administered normally?
- 28 weeks
2. Within 72 hours after delivery
If there are any factors that increase the chance of fetomaternal hemorrhage, what test can be done to see if another dose of RhoGAM is needed?
Kleinhauer-Betke test
What does the Kleinhauer - Betke test do?
Tests for fetal RBCs in maternal circulation
– Another dose of RhoGAM necessary
An Rh (-) woman with (+) Anti-D antibodies is considered?
Rh D SENSITIZED
If the woman is Rh (-), who should be tested next?
Father of the baby
If the Father of the baby is also Rh (-), next step?
NOTHING – baby will be Rh (-) so no treatment is needed
If the Father of the baby is Rh D (+), what should be done next?
Determine fetal Rh status
What is acquired often to estimate the severity of fetal hemolysis?
Maternal Rh - Antibody titers
If the maternal Rh - Antibody titers are < 1:8, what does that indicate?
Fetus is not in jeopardy of hemolysis
If the maternal Rh - Antibody titers are > 1:16, what does that indicate?
Fetus is in jeopardy of hemolysis!!!
If the Maternal Rh - Antibody titers are > 1:16, what tests should be done next?
- Fetal US
2. MCA doppler
What is the fetus most at risk of with Rhesus Isoimmunization?
Fetal Hydrops
What are the signs of Fetal Hydrops?
Ascites
Pleural/Pericardial effusion
Edema
Polyhydramnios