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Rh factorRh blood group system

Rh typingRh incompatibilitySymptoms

DetectionTreatmentPrevention of rh incompatibility

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•   The Rhesus factor gets its name fromexperiments conducted in 1937 by

scientists Karl Landsteiner and AlexanderS !einer

•   Their experiments in"ol"ed rabbits#hich$ #hen in%ected #ith the Rhesusmon&ey's red blood cells$ produced anantigen that is present in the red blood

cells of many humans

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•The genotype is determined by the inheritance

of 3 pairs of closely linked allelic genes situatedon chromosome 9 named as

D/d,

C/c,

E/e

……….. (Fisher- Race theory)

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• (irst demonstrated in rhesus mon&ey

• )lood groups are classi*ed as Rh positi"eand Rh negati"e

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• The Rh factor $ Rh+ and Rh, usually

refers speci*cally to the presence orabsence of antigen,-

• There are t#o alleles$ or genetic"ariants $ of this antigen. - and d

•A person #ho is Rh- has t#o recessi"e

traits$ dd Anyone #ho has at least one-,-- or -d,is Rh+

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• A person's Rh type is generally mostrele"ant #ith respect to pregnancies

• /f the pregnant #oman and her husband areRh negati"e$ there is no reason to #orryabout Rh incompatibility

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•/f she is Rh negati"e and her husbandis Rh positi"e$the baby #ill inherit the

father's blood type $creatingincompatibility bet#een mother andher fetus

•/f some of the fetal blood gets intomother's blood stream$ her body #illproduce antibodies

• These antibodies could pass bac&through the placenta and harm thede"eloping baby's red blood cells$

causing "ery mild to "ery serious

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•Rh incompatibility is acondition #hich de"elops#hen there is a di0erencein Rh blood type bet#een

that of the pregnantmother Rh negati"e2 andthat of the fetus Rhpositi"e2

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• sually placenta acts as barrier to fetalblood entering maternal

circulation4o#e"er$sometimes duringpregnancy or birth$fetomaternalhaemorrhage (542 can occur The #oman6simmune system reacts by producing anti,-

antibodies that cause sensitisation

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•/n subseuent pregnancies antibodies cancross placenta and destroy fetal erythrocytes

 The haemolytic disease of fetus and ne# borncaused by Rh isoimmunisation can occurduring the *rst pregnancy$ but usuallysensitisation during the *rst pregnancy or

birth leads to extensi"e destruction of fetalR)8 during subseuent pregnancies

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5iscarriage Abortion

(eto,maternal haemorrage

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• Rh incompatibility can cause symptomsranging from "ery mild to fatal

• Mildest form- Rh incompatibility:1,4emolysis -estruction of the red blood

cells2 #ith the release of free hemoglobininto the infant's circulation

 , :aundice 4emoglobin is con"ertedinto$bilirubin #hich causes an infant tobecome yello#

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(etalhemolysis

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 %aundice

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1, 4ydrops fetalis5assi"e fetal red blood

cell destruction2

, /t causes Se"ere

anemia

(etal heart failure -eath of the

infant shortly afterdeli"ery

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, Total body s#elling

3, Respiratory distress if the infant has beendeli"ered2

;, 8irculatory collapse

, /t occurs se"eral days after deli"ery and ischaracteri?ed initially by

  A2 Loss of the 5oro re@ex  )2oor (eeding

  82 -ecreased acti"ity

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At last it may lead to death of thechild immediately after its birth

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1,There are no any physical symptomscan be seen in rh incompatibility

,/f the #oman %ust found out she ispregnant$she should undergo blood,type test This test determines herblood type and Rh factor

3,)lood test that #ill determine #hethershe is Rh positi"e or Rh negati"e

DETECTI! " Rh

I!C#P$TI%I&IT' (

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$ntenatal(

-/ntrauterine blood transfusion /ntraperitonealtransfusion , blood transfused into fetal abdomen

-/ntra"ascular transfusion , blood transfused intofetal umbilical "ein

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23

•Postnatal(

,hototherapy for neonatal %aundice inmild disease

,Cxchange transfusion if the neonate hasmoderate or se"ere disease the blood fortransfusion must be less than a #ee& old$

Rh negati"e$ A)D compatible #ith boththe fetus and the mother$ and be crossmatched against the mothers serum2

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hototherapy of 

neonatal %aundice.

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)y using special immuneglobulins$ called E,RhoFA5E atG #ee&s of pregnancy

/f the baby is born Rh positi"e$another dose is administered#ithin 7 hours after deli"ery

 This #ill pre"ent her body fromcreating any future antibodiesthat could cause harm during a

pregnancy

PRE)E!TI!(

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!rong transfusion can cause agglutinationof blood in the recipient 4ence beforetransfusion of blood$ along #ithidenti*cation of A)D blood group$ it isnecessary to test compatibility of Rh factor

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Summary(

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