Rh INCOMPATIBILITY

Presented by –

Dr.Minal M. Patil (3rd Year B.A.M.S.)

Under guidance of

Dr. Jyotsna P. Patil (MD-Gynac)

Rh INCOMPATIBILITYIndex

- Introduction.

- Rh Blood group

- Heamolytic Disease of newborn

- Management

INTRODUCTION-

Fetal Circulation : Normally, there is no direct mixing of material & fetal blood

because all exchange occur by diffusion through capillary walls.

Blood

[Fetus Placenta]

Umbilical Artery Blood System : - ABO System

- Rh System

Blood Plasma contain antibodies called agglutinins.

RBC’s contain antigen

Landsteiner’s Law :- If particular antigen present on RBC, corresponding antibody must

be absent in serum.

If Antigen is absent on RBC’s the corresponding antibody mustn't be present in serum.

Group Antigen on RBC Antibody in Serum

A A Anti B (β)

B B Anti B (α)

AB A and B No antibody

O No antigen Anti A and Anti B

Rh blood group :-

It named because antigen was discovered in blood of Rhesus monkey.

- Rh factor is an antigen present in RBC’s- There are many Rh antigens but only the D is more antigenic. Person having ‘D’ antigen Rh+ve Person without ‘D’ antigen Rh-vea) Rh blood group system differ from ABO system antigen ‘b’ does not

have corresponding natural antibody (anti D) Rh-ve person is exposed of Rh +ve blood group for first time, then anti ‘D’ is formed in that person.

b) Rh +ve person receive Rh-ve blood without the risk of developing complication.

Defn :- Incompatibility means not suitable for combinations.

Inheritance of Rh antigen

Transfusion reactions due to Rh incompatibility

Rh -ve persons received Rh+ve blood at first time, not affected. Reaction not occur immediately But, the Rh agglutinitis develop within one month.

Transfused RBC’s which are still present in receipent’s blood, are agglutinated.

These agglutinated cells are lysed by macrophages. So delayed transfusion reaction occurs. But usually mild & does not after the recipent.

agglutinins developed in recepient body remain forever

Dectable antibody usually develop after 6 months following large volume of feto-maternal bleed. Antibodies once formed remain throught life.

But, when person receive Rh+ve blood for 2nd time. Severe transfusion reaction occur.

Hemolytic Disease of Newborn

When Rh-ve mother carries Rh+ve foetus.

Usually at first time child escapes the complications of Rh incompability. This is becoz Rh antigen cannot pass from fetal blood into mother’s blood through the placental barrier.

However, at time of parturation (delivery of the child) the Rh antigen from fetal blood leaks into mother’s blood becoz of serveranced of Umbilical cord.

During PPH period i.e. within a month after delivery, the mother develops Rh antibody in her blood.

When mother conceives for IInd time & if the fetus happens to be Rh+ve again, antibody from mother’s blood crosses placental barrier & enters the fetal blood.

Thus only Rh antigen can’t cross the placental barrier whear as Rh agglutin can cross it.

The Rh agglutinins which enter the fetus causes agglutination of fetal RBC’s resulting in hemolysis (i.e. Reputure of RBC’s)

Severe hemolysis in fetus causes Jaundice. To componsate the hemolysis of more & more number of RBC’s, there is rapid production of RBC’s not only from bone, but also from spleen & liver.

Now many large & immature cells in proerthyroblastic stage are released into circulation. Becoz of this, disease called Erythroblastosis fetalis.

Hydrops Fetalis :- Hemolysis is very severe leads to IUD to fetus.

death occur due to oedema, enlargement of liver & spleen & cardiac failure.

Kernicterus :- Brain damage in infants caused by Severe Jaundice.

by Anemia [in erythrocyte fetalis]

[Because in children, blood-brain barrier is not developed well so it can pass through this barrier and cause damage]

Increased bilirubin content

Bilirubin enters

Brain

Permanent brain damage.

While in fetus in utero destruction red cells

Liberation of unconjugate bilrubin

excreted

through

Placenta

Material system

A portion of bilirubin enters the amniotic fluid

Perhaps

From fetal long or through skin or across the surface of placenta or cord.

So this reason not directly born with Jaundice

as soon as

Umbilical Cord clamp

Hemolysis

Bilirubin

So baby become Jaundice

Coomb’s tests :-

[R.R.A. Combs Briton immunologist 1921]

Postnatal test of a sample of umbilical cord blood for maternal antibodies against the fetal blood type.

An abscences of agglutination signifies a normal negative finding & qualifies Rh-ve mother of administration of Rh Gamma to protect subsequent pregnancy.

Management

MANAGEMENT IN TWO TYPES

1) Rh –ve non – immunized patient

2) Rh –ve immunized patient.

Management of Rh- negative non immunized patient. Non

immunized group is formed by primigravida, multigravida patient who are Rh negative.

Father Rh factor mother Rh (-ve)

Negative (i.e. Rh-ve) Positive (Rh+ve)

Antibody Screening at 20, 24, 28 wks

No need for testing manage Antibody Screening Antibodytreat at normal pregnancy becomes +ve Screening remains - ve

manage as sensitized Give D-immunoglobulin pregnancy at 28th Wks & determing eligibility for IInd does

of D-immunoglobulin at delivery.

Indication for D-immunolobulin :

- Infants is Rh+ve- Direct coombs test on Umbilical cord blood is

negative

Test reveals Whether infants red cells are covered by irregular antibodies.

- Cross match between anti-D immunoglobulin & mother’s red cells is compactible.

DOSE Anti-D gamma globalin is administered IM to the mother 300

µg following delivery.

TIME

immunoglobulin given any time upto 4 wks after delivery.

Maximum protective effect is obtained if antibody administered

with in 72 hrs after delivery.

Management of Rh-ve immunized patient: Immonized Rh-ve patient Depends upon the 4 diagnostic techniques

1) Maternal serum antibody titre

2) fetal assesment by ultrasound

3) Amniotic fluid bilrubin determination

4) Fetal blood sampling.

Maternal Serum antibody titer :- - Useful for follw-up of patients in their first immonized

pregnancy.

- Patient in the course of their first sentisized pregnancy

should have antibody liters every 4 wks.

Fetal assesment by Ultrasound :- - High resolution Ultrasound is valuable in management

of sensitized Rh negative Pt.

- Modern equipment allows a clear visulasation of the fetal structures & early diagnosis of the presence of fetal ascites, pericardial effussion, liver management & placental swelling.

Amniotic Fluid analysis :- If pregnancy affected by presence of irregular

antibodies capable of producing erythroblastosis fetalis spectro- photometric analysis of amniotic fluid is reliable method for evaluating severity of fetal hemolytic process & for determining optimal time for IUT [Intrauterine transfusion]

- Ist amniocentesis is carried out at 26 wks.

Fetal blood sampling or transfusion – The site of placental insertion of umbilical cord is

found using high resolution USG needle is introduced into umbilical vein & fetal blood is drawn for determination of fetal blood group

- Rh +ve / -ve

- Fetal Hb.

- Haemocrit value.

Prognosis :- Prognosis of the baby depends on

1) Genotype of fetus

2) Maternal antibody level

3) History of Previous affection of the baby due to hemolytic disease

4) availability of diagnostic & therapeutic facilities for the affected babies.

Advice :-

An immunised mother who has anti-D level more than 400 IU/L should be advised for anti-D donation.

Care During Delivery :- C4

* Careful Vaginal delivery :-

1) Fetal monitoring is to be detect at the earliest evidence of distress.2) Prohylatic ergometrine during second stage should be withheld.3) Gentle handling of uterus in the third stage.4) Care of PPH.

* Cesarean Section :-

- To avoid spillage of blood into peritoneal cavity.

- Routine manual removal of placenta should be with held.

* Clamping the umbilical cord :-

1) Cord is clamp as quaickly as possible.2) Cord should be kept long for exchange transfusion is required.

• Collection of cord blood for investigation :-

1) Collected 5ml of blood (2 ml oxalated) (3 ml clotted)

2) Clotted blood - Rh grouping - direct coomb’s test

3) Oxalated blood - Hb% estimation.