P.X.Antony

Assistant Professor

Department of Microbiology

RAGACOVAS

PUDUCHERRY

pxantony@gmail.com

ICT applications 10th June 2009

Rh Factor

Individuals whose red blood cells agglutinate

when mixed with antibodies to rhesus

monkey blood are called

rhesus positive (Rh+)

Individuals whose blood does not agglutinate

when mixed with antibodies to rhesus

monkey blood are called called

rhesus negative (Rh-)

ICT applications 10th June 2009

Rh Negative

(No agglutination)

Rh Positive

(agglutination)

Rh typing

ICT applications 10th June 2009

The Rh antigen is found on the red blood

cells of

85% of whites

96% of blacks and

99% of Asians

ICT applications 10th June 2009

If a Rh- mother becomes pregnant by a Rh+

father and If baby is Rh+

This means a Rh+ baby growing in a Rh-

mother.

At the time of birth some of the baby's blood

gets into the mother's circulation.

ICT applications 10th June 2009

This sensitizes the mother to Rh+ blood and

she produces anti-Rh+ antibodies.

These antibodies do not affect the first baby

as they are produced in her blood after this

baby is born.

ICT applications 10th June 2009

If she has a second pregnancy with a Rh+

baby her antibodies may cross the placenta

and destroy the baby's red blood cells.

This condition is called

erythroblastosis foetalis.

ICT applications 10th June 2009

Rh - Rh +

Rh +

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At the time of delivery

Rh + cells from foetus enters mother

Rh +

Rh -

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Mother develops antibodies

to Rh + cells from foetus

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Mother’s immune system

Second Pregnancy

Rh +

Rh -

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Antibodies to Rh + cells enter

foetal circulation

Rh +

Rh -

Excessive destruction of RBCs leads to jaundice

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The baby either suffers from jaundice

Anaemia

Lack of blood supply to brain leads

serious brain damages

Stillbirth

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These serious damages can only be

prevented by a complete exchange of the

newly born baby's blood.

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Treatment

Administration of Rhogam (antibodies

to Rh + cells) to mother just after

delivery of the first child

Rhogam neutralises Rh+ cells thus preventing

the production of anti-RH+ antibodies

Thank you

Thank you

ICT applications 10th June 2009