Dr.Suresh Babu Chaduvula

Professor

Department of Obs & Gyn

College of Medicine

KKU, Abha, Saudi Arabia

Karl Landsteiner – Proposed Blood Group

Sysytem

Awarded Nobel prize in 1930

Landsteiner and S.Weiner – discovered

Rhesus system in Rhesus monkeys.

RBC cell surface has antigens called

Agglutinogens or isoagglutinogens and

plasma contains antibodies called

Agglutinins or isoagglutinins.

A positive woman will have A antigen and

anti B antibodies.

Rhesus positive mothers means D antigen

positive.

Rhesus negative means D antigen negative

mothers.

There are 5 Rhesus antigens – D, C,c,E and e.

Out of which D antigen is most powerful

antigen.

Other antigens like Kell and Duffy antigens.

Anti- kell is very serious.

Sensitization of maternal immune system to

produce antibodies after exposure to fetal

RBC antigens.

Allo or Isoimmunisation – means immune

response to foreign antigens from the same

species.

Prevalence is 1%.

1. Mismatched blood transfusion

2.Feto maternal hemorrhage following

delivery, ectopic pregnancy, abortions.

3. Invasive procedures like Chorionic villous

sampling, Amniocentesis in pregnant mothers

4. APH – Placenta Previa, Abruption of

placenta

5. External cephalic version

6. Intrauterine fetal death

Feto-maternal hemorrhage of Rh positive cells enter into maternal circulation and will produce anti – D antibodies Ig M type initially called –Sensitisation.

After a minimum period of 3 months IgGantibodies are produced which are capable of crossing placental barrier.

IgG antibodies attack and destroy fetal RBCs in spleen and produce Hemolytic anemia of Newborn.

Anemia will produce erythropoiesis in liver leading to erythroblast production called Erythroblastosis fetalis.

In a mother who is already sensitised will

have a very severe hemolytic anemia and

hyperbilirubinemia called Icterus Gravis

Neonatorum.

If this unconjugated bilirubin crosses blood

brain barrier it will stain basal ganglia called

Kernicterus

And hypo-proteinemia which will lead to

changes in hemeodynamics results in

accumulation of fluid all over the body and

also in body cavities called Hydrops fetalis.

Antenatally at 28 and 34 weeks Anti D

Immunoglobulin of 300 micrograms should be

given.[ decreases immunization by 0.2%]

Anti D Immunoglobulin of 300 micrograms

should be given within 72 hours called

RhoGAM.[ decreases immunization by 1.5%]

Following all invasive procedures also it

should be given.

300 micrograms can protect from 30 ml of

bleed.

1. Increases with each subsequent pregnancy

2. Depends on paternal zygosity

3. Amount of feto-maternal bleeding

4.ABO incompatibility.

Initially sensitization occurs in 1st pregnancy.

Later due to memory in the immune system

response for antibodies will be very high.

Amount of antibody production varies with

the amount of fetal RBCs entered into

maternal circulation.

Quantity tests for FMH is done by

1.Kleihuer-Betke test

2.Flow cytometry

It occurs in mothers with ‘O’ blood group.

The antibodies in this group are weak

hemolysins.

These can attach to only few fetal RBCs

It may produce only mild hyper bilirubinemia

but not Hydrops.

These antibodies and mild hemolysis will

decrease Rh iso- immunization and

hemolysis.

Do Blood group and type of partners

Anti D immunoglobulin at 28/ 34 weeks

Anti D immunoglobulin within 72 hours

Assess amount of feto-maternal hemorrhage

and if amount is more than 30 ml adjust the

dose.

Assess accurately gestational age by USG

Blood group and typing of partners

Assess Antibody titer – by Indirect Coomb’s

test – every 2-4 weeks

Amniocentesis – at a critical titer 1:16 to

assess the hemolytic anemia

To determine the amount of bilirubin which

is produced by fetal hemolysis and is

secreted by secretions from fetal body.

Spectrophotometric analysis is used to find

out level of bilirubin in amniotic fluid.

Bilirubin causes shift of optical density from

linearity. Shift is greatest at 450 nanometer.

Degree of shift at 450 nm called Delta OD

[OD 450] indicates degree of hemolysis.

Delta OD at 450 should be plotted in Liley

chart.[used between 27 to 41 weeks]

I t has X axis –indicates gestation in weeks

and Y axis about Delta OD.

It has 3 zones called Low, Mid and High Zone.

Delta OD may fall either of the zones and

gives approximate time for time of delivery.

This chart also helpful in preventing

iatrogenic preterm delivery.

Low zone indicates - mild anemia -

Mid zone –mild to severe anemia

High zone – severe anemia and impending

fetal death within 7-10 days.

Like a normal pregnancy deliver at 38 weeks

Do regular ultrasound and may have to

repeat amniocentesis.

Fetal well being tests – NST, CTG, Biophysical

profile, Doppler study.

High mid and High zone will require

CORDOCENTESIS – to assess fetal hemoglobin,

hematocrit , platelets and group and type,

reticulocyte count fetal transfusion through

umbilical vein and delivery.

Transfusion of O negative fresh blood if

hematocrit is less than 30%.

1. Intra peritoneal

2. Intra vascular – umbilical vein

Transfusion can be given till fetal hematocrit

becomes normal till the risk of prematurity is

crossed.

A] Ultrasound – to determine hydropic changes

like

1. scalp edema

2. Anasarca

3. Effusions

4. Hepato and spleenomegaly

5. Umbilicalomegaly

6. Placentomegaly

B] Doppler Velocimetry –

Assess peak systolic velocity in middle

cerebral artery, aorta, vena cava and umbilical

vein. It will be increased in severe anemia.

C] CTG – NST

D] Biophysical profile

Low Zone & Low Mid Zone - – Deliver at 38

weeks.

High mid zone High Zone – Deliver at 34

weeks electively by cesarean section .

Arrange adequate amount of O negative

fresh blood for the newborn.

Inform the neonatologist prior to the

delivery.

Higher tertiary centers is ideal place for

delivery.

THANK YOU ALL

AND

ALL THE BEST