A reviewer by Jerard Domingo

1. Rh Incompatibility
BY: JERARD LLOYD B. DOMINGO
BSN 2A
It is easier to study with a pen
and paper para makasunod sa
topic :)

2. Rh Incompatibility
 A condition that occurs during pregnancy, by which a
mother has an Rh (-) blood, and her baby has Rh(+) blood.
 It occurs when the mother and the fetus has incompatible
blood factors specifically the Rh Factor.
 It usually occurs when an Rh (-) mother and a father with Rh
(+) conceived a child (nagkaanak).
 The mother's body will create antibodies against the baby's
blood.
 It is also knonwn as Hemolytic Disease of Fetus and Newborn
(HDFN). It is less common, but more severe.

3. Rh Factor
 Rh Factor - also called as Rhesus
factor. It is an inherited protein
found on the surface of RBC.
 If you have Rh Antigen in your
blood, ikaw ay Rh positive.
 But if if you do not have Rh Antigen
in your blood, ikaw ay Rh Negative.
*Rh Factor does not directly affect the health.
*However, Rh factor becomes important during pregnancy.

4. Rh Factor
 RhAg (antigen) are found on the
surface of the RBCs that may cause
isoimmunization.
 D Antigen is the most powerful Rh
Factor. if you possess it, you are Rh+,
and if not, you are Rh-.
 Exposure of Rh- people to even small
amounts of Rh+ blood, can result in
the production of anti-D allo-antibody
that may lead to Rh sensitization or
isoimmunization.

6. Key Terms
-Alloimmunity - (sometimes called isoimmunity) is an
immune response to nonself antigens from members of
the same species, which are called alloantigens or
isoantigens. Allo means other. Meaning, that this
alloimmunity is a reult of a non-self antigens.
-Rh Sensitization - when you’re Rh-negative, your body
treats Rh-positive blood that you come in contact with as
a foreign substance and builds antibodies to protect itself.
-Hemolysis - the destruction of red blood cells.
-Hemolytic anemia - refers to anemia caused by the
excess destruction of red blood cells.

7. Rh Incompatibility
 Usually, kapag Rh positive ka, or Rh negative there's no
problem na lumalabas.
 But in pregnancy, Rh incompatibility causes
complications to occur in the fetal development.
 Nangyayari lamang ang Rh Incompatibility kapag Rh
Negative ang nanay, at Rh positive ang Fetus.
 Kapag Rh positive naman ang nanay, at Rh positive din ang
developing baby, walang immune response ang nanay kasi
pareho silang may Rh Factor sa blood or Rh+.

8. How Rh Sensitization occurs?
 At the end of pregnancy, especially on the day of labor and delivery,
small to large amounts of blood from the baby (Rh+) mix with maternal
blood (Rh-). So ibig sabihin, naihalo ang blood ng baby sa maternal
circulation.
 Paano nangyari ito?
- When the time that the placenta detaches itself from the
endometrium, rupture of blood vessels occur, causing leaks of blood from
the placenta to mix with maternal blood circulation.
 Ang ibig sabihin nito, kapag incompatible ang Rh factors ng nanay at
fetus, at nagmix ang blood nila (during labor & delivery), there's a very
high probability that the maternal blood will create it's own antibodies
against the Rh + blood of the fetus or also called as Rh sensitization.

9. Rh Incompatibility
 Rh sensitizaton - maternal antibodies will be formed and later
will attack the fetal RBC's that may cause fetal RBC to die
(hemolysis).
*Bakit nangyayari ang sensitization?
- Dahil ang dugo ng nanay ay Rh negative o walang Rh
factor, at ang baby ay Rh positive o mayrong Rh factor, ang
maternal immune response ng nanay will think that the baby is
a foreign substance that may cause harm. This will cause
sensitization of the mother or pagkabuo ng antibodies na
against Rh positive Blood.

10. Result of Rh Sensitization
 As a result, when Rh antibodies of the mother are formed,
subsequent pregnancies will be attacked by the maternal
antibodies and cause serious damage with the baby such as
destruction of RBCs (hemolysis) that can cause severe
anemia.
 Role of Red Blood cells - to carry oxygen throughout the
body, to vital organs and tissues. So therefore, if RBCs are
destroyed,
 Rh Incompatibility may cause severe anemia on the fetus. It
means that signs and symptoms of anemia are present on
the newborn or fetus.

11. Pathogenesis
Entry of Fetal
Rh+ blood into
maternal
circulation
Rh Sensitization
1. Rh+ mother carrying an Rh- fetus
- The chance of having Rh+ve fetus from Rh+ve
father ranges from 50% -100%.
 Father (Rh+) + Mother (Rh+) = Fetus (Rh+) = No
problem
 Father (Rh-) + mother (Rh-) = fetus (Rh-) = No
problem.
*However; Father (Rh+) + mother (Rh-) = 50%(Rh-)
50% (Rh+)

12. Pathogenesis
Entry of Fetal
Rh+ blood into
maternal
circulation
Rh Sensitization
2. Entry of the fetal Rh+RBC into maternal circulation
- Transfusion of incompatible blood (rare)
- Fetomaternal hemorrhage(through leaks in the
placenta- 3rd stage of labor)
-Spontaneous/ induced abortion
-Ectopic gestation (tubal rupture)
- Antepartum hemorrhage: abruptio placenta,
amniocentesis, abdominal trauma, external cephalic
version.
-Worsen fetomaternal bleeding during labour are
manual removal of placenta, twin delivery and
caeserian section.

13. 1st Pregnancy with Rh Incompatibility
NUMBER 1 IS FINE!
1st Baby is fine.
Ligtas sa isoimmunization
ang first baby.
How is that possible?
- Most pregnancies that Rh Factor is
incompatible, the mixing of maternal and
fetal blood occured after the delivery of the
1st baby. So ibig sabihin nun, ang
sensitization o isoimmunization sa nanay ay
nangyari after madeliver ng First Rh
incompatible na baby. Nakalabas na
muna si baby from the uterus, bago
madevelop or maactivate ang antibodies
ni mommy against an Rh+ blood.
Note: But depending on the
case, because early blood
to blood contact like
amniocentesis in early
pregnancy, and abruptio
placenta, there is still a
chance that the first baby
can develop severe anemia
as a result of early
isoimmunization.

14. 2nd, 3rd, 4th, and Subsequent Pregnancy
If the mother was sensitized
with her 1st pregnancy,
pwedeng ang mga
kasunod na pagbubuntis
ay magkaroon na ng
isoimmunization IF THE
FETUS IS Rh+ AGAIN. Pero
kung Rh- na ang kasunod
na pregnancy, no blood
complications will occur
kasi same blood factor na
ang mother and fetus.
How is that possible?
-Usually between first and second trimester,
the mother passes her antibodies to the
fetus for its protection. it is the process
called, PINOCYTOSIS.
*Pinocytosis - maternal antibodies are
passed to the fetus.
*So it means na kapag ang mother ay
already sensitized from her first pregnancy,
she can pass the Rh+ antibodies to her 2nd
pregnancy, that will result in fetal
complications.

15. Factors that causes Blood to Blood Contact
1. Labor & Delivery - causes maternal blood and fetal blood contact
when the placenta detaches itself from the uterine wall. Ruptured BV
from the placenta, causes leak of blood from fetus to enter the maternal
circulation.
2. Blood Transfusion - due to blood mismatching, an Rh+ blood is
transfused with an Rh- recipient causing sensitization.
3. Ruptured Ectopic Pregnancy
4. Placental Abruption
5. Abortion (spontaneous or induced)
6. Absent Cytothrophoblast of placenta - no barrier between placenta
and uterus.
7. Amniocentesis

16. Factors that causes Blood to Blood Contact
ANY FORM OR PROCESS THAT BREAKS
THE PLACENTAL BARRIER WILL CAUSE
FETAL BLOOD TO MIX WITH MATERNAL
BLOOD CAUSING SENSITIZATION.
The amount of fetal blood necessary to produce Rh incompatibility
varies. In one study, less than 1 mL of Rh-positive blood was shown
to sensitize volunteers with Rh-negative blood. The risk and severity
of sensitization response increases with each subsequent pregnancy
involving a fetus with Rh-positive blood. In women who are prone to
Rh incompatibility, the second pregnancy with an Rh-positive fetus
often produces a mildly anemic infant, whereas succeeding
pregnancies produce more seriously affected infants who ultimately
may die in utero from massive antibody-induced hemolytic anemia.
In 90% of cases,
sensitization occurs
during delivery.
Therefore, most firstborn
infants with Rh-positive
blood type are not
affected because the
short period from first
exposure of Rh-positive
fetal erythrocytes to the
birth of the infant is
insufficient to produce a
significant maternal IgG
antibody response.

17. Pathogenesis of Rh Incomp to the Subsequent Pregnancies
Step by Step. The Mother is
1. Diffusion - antibodies from the mother crosses the placenta and diffuse in the fetal circulation.
2. Attachment - maternal Rh+ antibody will be attached to the fetal antigen (D-antigen) .
3. Agglutination - clumping of RBC causing lysis (cell death). It occurs due to the antibody-antigen
reaction of the fetomaternal blood.
4. Lysis - maternal antibodies or macrophages will produce lytic enzymes that will destroy the fetal
RBC.
5. Phagocytosis - macrophage will consume the fetal RBC causing hemolysis.
6. Inhibition in the conversion of unconjugated bilirubin to conjugated bilirubin due to hemoglobin
breakdown. Unconjugated bilirubin needs the process of conjugation by the hemoglobin to make it
water soluble and become excreted in the urine. So therefore, unconjugated bilirubin which is a lipid
soluble will leak to the blood brain barrier.
7. Extramedullary Hematopoiesis - the bone marrow will compensate, but later will be exhausted, so
other organs such as spleen and liver will work to immediately produce RBC. Extra - outside.
Medullary - bone marrow. Hematopoiesis - formation of new blood.

18. Clinical Manifestations (Fetal)
1. Severe Anemia - due to RBC destruction. Signs and symptoms of anemia will
result (jaundice, low oxygen levels, cold & clammy skin)
2. Heart Failure - due to severe anemia, O2 levels fall, the heart compensates
and later get exhausted and cause high output cardiac failure. It can cause
hydrops fetalis.
*Hydrops Fetalis - accumulation of water in the fetal compartments. also
known as “fetal edema” as a result of elevated venous hydrostatic pressure due
to heart failure .
3. Neonatal Jaundice - as a result of hemolysis, bilirubin levels accumulate in
cells.
4. Splenomegaly and Hepatomegaly - as a result of extramedullary
hematopoiesis, the spleen and liver compensate to produce RBC. But RBCs they
produced are nucleated RBCs and erythroblasts which are immature RBC.

19. Clinical Manifestations (Fetal)
5. Kernicterus - a bilirubin-induced
brain dysfunction. It is caused by
hyperbilirubinemia. Because the
hemoglobin is broken down via
hemolysis, the conjugation of
unconjugated bilirubin is blocked.
*Unconjugated Bilirubin is a lipid
soluble, and known as a
neurotoxicsubstance that can
penetrate in the (BBB) blood-brain-
barrier of the CNS, therefore, bilirubin
accumulates in the grey matter of
the CNS that causes neurological
damage.

20. Diagnosis
1. Coomb's Test - to detect if antibodies are in RBC's surface.
2. Blood Film (peripheral smear) - to detect if spherocytes are
present. Usually they are absent because the macrophage
consumed all the fetal RBC.
3. CBC - to determine if Hgb and Hct levels are normal. indicates
early hemolysis. Immature RBC or reticulocytes are elevated
that due to extramedullary hematopoiesis.
4. Blood Typing - to provide early anti-D (RhoGAM) prophylaxis.

21. Prevention
1. Pre-natal Care
- Assessment of maternal blood typing. If the mother is Rh+,
there are no further treatments given.
- If the mother is Rh- , she will need a RhoGAM shot at 28-30 weeks
and then within 72 hours after delivery.
*Rhogam - it is an artificial anti-D, or Rho drug that stops the immune
system from creating antibodies against an Rh+ blood. It is also given
with subsequent pregnancies when the baby is Rh+ and mother is Rh-.
Note: RhoGAM is only used if mother is unsensitized. Rho(D) immune
globulin or RhoGAM is a derivative of human plasma that cannot pass
the placenta. Meaning it is safe during pregnancy, and it will prevent
isoimmunization.

22. Entry of Fetal Rh+
blood into maternal
circulation
Rh Sensitization
First Baby is Fine
High Chance of
isoimmunization
2nd baby (Rh+) again
Hemolysis of RBC
Severe Anemia
Heart Failure
Hyrops Fetalis
Hyperbilirubinemia
Jaundice
Kernicterus
Extramedullary
Hematopoiesis
Splenohepatomegaly
accumulation to
grey matter of
CNS