Rh incompatibility occurs when a pregnant woman who is Rh negative is carrying a baby who is Rh positive. During pregnancy or delivery, the baby's blood can enter the mother's bloodstream and cause her to produce antibodies against the Rh positive blood. These antibodies can then cross the placenta and destroy the baby's red blood cells, causing hemolytic disease of the newborn. To prevent sensitization, Rh negative mothers are given Rh immunoglobulin during and after pregnancy to prevent production of antibodies against Rh positive blood. Failure to prevent sensitization can lead to jaundice, anemia, heart failure or even death for an Rh positive baby in subsequent pregnancies.

1. Rh- incompatibility
Anjana Thomas

2.  The Rhesus factor gets its name from
experiments conducted in 1937 by scientists
Karl Landsteiner and Alexander S Weiner.
 Their experiments involved rabbits which, when
injected with the Rhesus monkey’s red blood
cells, produced an antigen that is present in the
red blood cells of many humans.

4.  Rh incompatibility is a condition which
develops when there is a difference in Rh
blood type between that of the pregnant
mother(Rh negative) and that of the fetus
(Rh positive)

5.  A person’s Rh type is generally most relevant with
respect to pregnancies
 If the pregnaant women and her husband are Rh
negative, there is no reason to worry about Rh
incompatibility
 If she is Rh negative and her husband is Rh positive,
the baby will inherit the father’s blood type,
creating incompatibility between mother and her
fetus

6.  If some of the fetal blood gets into mother’s
blood stream, her body will produce
antibodies.
 These antibodies could pass back through the
placenta and harm the developing baby’s red
blood cells.

7.  Usually placenta acts as barrier to fetal
blood entering maternal circulation.
However, sometimes during pregnancy or
birth, fetomaternal haemorrhage can occur.
The women’s immune system reacts by
producing anti D antibodies that causes
sensitization.

8.  A difference in blood type between a
pregnant woman and her baby causes Rh
incompatibility. The condition occurs if a
woman is Rh negative and her baby is Rh
positive.

9.  An earlier pregnancy
 An ectopic pregnancy, a miscarriage or an
induced abortion.
 A mismatched blood transfusion or blood and
marrow stem cell transplant.
 An injection or puncture with a needle or
other object containing Rh positive blood

10.  1st pregnancy
Father RhD +
Mother RhD –
Fetus RhD + Fetal – maternal blood
transfer during labour
First newborn
RhD + safe
But mother RhD
– is now
sensitized to
Rhd antigen

11.  Second pregnancy
Rapid
production
of IgG anti
D by
mother
Maternal
IgG anti D
crosses
placenta
IgG anti D
attaches to
fetal BBC &
marks them
for
destruction
Fetal or
newborn
hemolytic
anemia
Increased
billirubin,
CNS
damage(ker
nicterus),d
eath
Repeat
encounter
with
Fetal
RhD
antigen

13.  The klehauer- betke test or flow cytometry
 Indirect coomb test
 The direct coomb test
 Blood count
 Billirubin – direct & indirect

14.  Mildest form
 Hemolysis
 Jaundice
 Total body swelling
 Respiratory distress
 Circulatory collapse
 Kernicterus
 It occur several days after delivery – poor
feeding, decreased activity

15.  Hydrops fetalis
 Icterus gravis neonatrum
 Congenital anemia of newborn

16.  This is a most serious from of Rh haemolytic
disease. Excessive destruction of the fetal
red cells leads to severe anaemia, tissue
anoxaemia and metabolic acidosis.

17.  This clinical entity is the effect of lesser
form of fetal haemolysis. The baby is born
alive without evidence of jaundice but soon
develops it within 24 hours.

18.  Mildest form of diseases where the
haemolysis is going on slowly. Although
anemia develops slowly with in first few
weeks

19.  Rh incompatibility is treated with a medicine
called Rh immunoglobulin. Treatment for the
baby who has hemolytic anemia will vary based
on the severity of the condition
 If Rh incompatibility is diagnosed during
pregnancy, mother will receive Rh
immunoglobulin in seventh month of pregnancy
and again with in 72 hours of delivery.

20.  Mother also may receive Rh immunoglobulin
if the risk of blood transfer between mother
and the baby is high (for example, a
miscarriage, ectopic pregnancy, or bleeding
during pregnancy)

21.  Immunization with Rh immunoglobulin
 Prevent or minimize feto maternal bleed
 Avoid mismatched transfusion
 Amniocentesis should be done after
sonographic localization of placenta