Hemolytic Disease of the Fetus and Newborn (F) Flashcards
What is hemolytic disease of the newborn (HDN)?
It is an alloimmune condition that develops in a fetus
When does HDN occur?
When the IgG molecules produced by the mother are passed through the placenta
When the mother does not have the Rh factor present in her blood, but the fetus has this factor
Among the IgG produced by the mother, what is the action of some of these Abs?
They attack the RBCs in the fetal circulation
What happens in HDN?
The RBCs are broken down
What are the results of hemolysis of fetal RBCs?
1) Reticulocytosis
2) Anemia
What is the range in terms of severity of HDN that can occur?
From mild to very severe, and fetal death
What is the cause of fetal death?
Heart failure
What are present in the fetal blood if HDN is moderate or severe?
Many erythroblasts
What is erythroblastosis fetalis?
It is the form of HDN (specifically the moderate / severe ones) whereas many erythroblasts are present
What is the other name of erythroblastosis fetalis?
Erythroblastosis foetalis
When does HDN occur (explain its principle / mechanism)?
It occurs when the fetus has a blood grp Ag that the mother does not possess. Whereas the mother’s body forms an Ab against that particular blood grp Ag, and hemolysis begins
The process of Ab formation is called as what?
Maternal sensitization
Why does the fetus (w/ HDN) acquired anemia?
Due to the hemolysis of RBCs
Due to the anemia of the fetus, what does the body of fetus do?
It compensates by producing large #s of immature erythrocytes (w/c are reticulocytes)
What are the other names of HDN?
1) Erythroblastosis fetalis
2) Hydrops fetalis
What is hydrops?
It refers to the edema
What is fetalis?
It refers to the lethal state of the infant
If HDN is present due to Rh incompatibility, hemolysis usually begins where?
In utero
Does HDN (due to Rh incompatibility) affect the 1st pregnancy of the mother?
The 1st pregnancy may not be affected
What are the pregnancies that will be affected by HDN?
The succeeding pregnancies of the mother
If the HDN present is due to ABO incompatibility, when does hemolysis usually begin?
The hemolysis does not usually begin until the birth of the newborn
What is the blood grp Ag present in the fetus?
Rh Ag (specifically D Ag)
Aside from Rh incompatibility, what is the other cause of hemolytic disease?
ABO incompatibility
What is the blood type of the mother and the blood types of the fetus present in most cases of HDN (due to ABO incompatibility)?
Mother: type O
Fetus: either type A, B, or worst is AB
What is the principle of HDN (due to ABO incompatibility) in relation to difference in blood type between mother and fetus? Provide / explain each context
Mother: type O
Fetus: type A
-> the anti-A of the mother will attack the A Ag of the fetus
Mother: type O
Fetus: type B
-> the anti-B of the mother will attack the B Ag of the fetus
Mother: type O
Fetus: type AB
-> the anti-A and anti-B of mother will attack the A and B Ags of fetus, hence, this case is worst than the other 2
Hemolysis in HDN is occasionally caused by what?
Maternal anemias (such as thalassemia or from other blood grp Ags [anti-D])
What is 1 of the signs of HDN?
Hemolysis (w/c leads to elevated bili lvls), hence, the neonate has jaundice
What is jaundice?
It is the condition whereas the pt is characterized as having symptoms such as yellowish skin and yellow discoloration of the whites of the eyes (/ sclera of the eyes)
What is the reason for the jaundice of the neonate?
Because after delivery of the pt, bili is no longer cleared (via the placenta) from the neonate’s blood
When does the symptoms of jaundice increase?
These increases within 24 hrs after birth
In other cases of severe neonatal jaundice, what can possibly occur?
Acute or chronic kernicterus
Profound anemia (due to hemolysis) can cause what?
1) High-output heart failure (/ high-output cardiac failure), w/ pallor
2) Enlarged liver and/or spleen
3) Generalized swelling
4) Respiratory distress
What are the prenatal manifestations of HDN?
1) Hydrops fetalis
2) Petechiae and purpura (especially in severe cases)
3) Infant may be stillborn or die shortly after birth
The dx of HDN is based on what?
1) History
2) Lab findings
What are the blood tests that can be done on the newborn baby?
1) Biochemistry tests for jaundice
2) Peripheral blood morphology shows increased reticulocytes
3) Presence of erythroblasts (in moderate and severe disease)
4) (+) direct Coombs test (might be [-] after fetal interuterine blood transfusion)
Erythroblasts are also known as what?
Nucleated RBCs
What is the blood test that can be done on the mother?
(+) indirect Coombs test
What is the action of Coombs test?
To detect Rh incompatibility between mother and fetus
What is the mechanism / principle of Coombs test?
This test uses Abs that bind to anti-D Abs
Coombs test is named after what?
Robin Coombs
Who is Robin Coombs?
He is the 1st to develop the technique of using Abs that are targeted against other Abs
In HDN, direct Coombs test is used for what?
For dx of HDN
What is the action of direct Coombs test (for diagnosing HDN)?
To detect maternal anti-D Abs that have already bound to fetal RBCs
What is the procedure of direct Coombs test?
1) A sx of fetal RBCs is washed to remove any unbound Ab (Ig)
2) When the test Abs (anti-Ig) are added, they agglutinate any fetal RBCs to w/c maternal Abs are already bound
Why is direct Coombs test called as its name?
Because the anti-Ig binds directly to the maternal anti-D Ig that coats fetal RBCs in HDN
In HDN, indirect Coombs test is used for what?
For the prevention of HDN
What is the action of indirect Coombs test?
It finds anti-D Abs in the mother’s serum
What will happen if the anti-D Abs in the mother’s serum come into contact w/ fetal RBCs?
The anti-D Abs will hemolyze the fetal RBCs, hence causing HDN
When is treatment given (in indirect Coombs test)?
When it is found out that maternal anti-D before fetal RBCs have been attacked
What is the purpose of providing treatment when it is found out that maternal anti-D before fetal RBCs have been attacked?
To prevent / limit the severity of HDN
What is the procedure of indirect Coombs test?
1) The mother’s serum is incubated w/ D-(+) RBCs
- > if any anti-D is present in the mother’s serum, they will bind to the cells
2) The cells are then washed to remove all free Abs
3) When all Abs are added, they will agglutinate any RBCs to w/c maternal Abs are bound
Why is indirect Coombs test called as its name?
Because the anti-Ig finds indirect evidence of harmful maternal Abs, requiring the addition of fetal RBCs to show the capacity of maternal anti-D to bind to fetal RBCs
Before birth (of the fetus), what are the options for treatment (/ management of HDN)?
1) Intrauterine transfusion or early induction of labor
2) Plasma exchange
What can be present if intrauterine transfusion is done?
Fetal distress
When is early induction of labor done (if intrauterine transfusion is not present)?
When the baby has reached pulmonary maturity and if he/she is capable of breathing outside the uterus
When does the baby reach pulmonary maturity?
If 35 - 37 wks of gestation have passed
What process can be done to the mother as an option for treatment (/ for management) of HDN prenatally?
Plasma exchange
What is the purpose of plasma exchange?
To reduce the circulating lvls of Ab by as much as 75%
What is given to mothers (who are Rh-[-]) who have had a pregnancy w/ or are pregnant w/ an infant (who is Rh-[+])?
Rh immune globulin (RhIG) / RhoGAM
When is RhIG given to the mother?
1) At 28 wks during pregnancy
2) At 34 wks
3) Within 72 hrs after delivery
What is the purpose of giving the mother w/ RhIG?
To prevent sensitization to the D Ag
What is the process in terms of administering RhoGAM?
1) Administer RhoGAM to the unsensitized Rh-(-) client as appropriate
2) Provide management for the sensitized Rh-(-) mother and Rh-(+) fetus
3) Provide management for ABO incompatibility
RhoGAM should be administered at 28 wks of gestation even in the presence of what contexts?
1) Even when titers are (-)
2) After any invasive procedures (such as amniocentesis)
What is the action of RhoGAM?
To protect against the effects of early transplacental hemorrhage (as recommended by the American College of Gynecologists)
When the Rh-(-) mother is in labor, what should be done (in relation to administration of RhoGAM)?
Crossmatch for RhoGAM should be done w/c must be given within 72 hrs of delivery of the newborn
Where should management for the sensitized Rh-(-) mother and Rh-(+) fetus be done?
Focus management of the sensitized Rh-(-) mother on close monitoring of fetal well-being, as reflected by Rh titers, amniocentesis results, and sonography
In connection to providing management for the sensitized Rh-(-) mother and Rh-(+) fetus, what should be done if there is evidence of erythroblastosis?
Notify the perineal team of the possibility for delivery of a compromised newborn
What can be usually done to resolve the newborn’s jaundice (w/c is associated w/ ABO incompatibility)?
Phototherapy
What are the immediate measures that may be required to reduce indirect bili lvls?
1) Initiation of early feeding
2) Exchange blood transfusions
In terms of providing management for ABO incompatibility, what is the other thing that can be done?
Provide client and family teaching
What are the things / ways / resolutions that can be done to prevent the occurrence of HDN?
1) Determine Rh status of mother
2) If the mother is not sensitized, reduce the risk of future sensitization
3) If the mother is sensitized, whether the fetus is at risk and monitor accordingly
