Rhesus Disease and Fetal Hydrops Flashcards Preview

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Flashcards in Rhesus Disease and Fetal Hydrops Deck (10):

Explain the general principle of how rhesus disease occurs?

Rhesus negative anti D mother.

1st child is Rh positive during child birth mixing of blood.

Mother develops Anti Rh D antibodies.

During second pregnancy these antibodies can cross the placenta, if the second child is Rh D +ve then these antibodies will attack the fetal red blood cells.

This will cause haemolysis resulting in:
-Neonatal jaundice and anaemia
-If severe fetal hydrops and fetal death


What is the principle of rhesus isoimmunisation?

At 28 weeks a blood group and antibody screen is performed.

If the women tests positive for anti D then they should be given anti D prophylaxis.

Should also be given to women who have had potentially sensitising events ideally within 72hrs of event.


What events are classed as sensitising with regards to developing anti D Ig?

-Invasive prenatal diagnosis - eg, amniocentesis.
-Antepartum haemorrhage.
-Ectopic pregnancy.
- Any intrauterine procedures (eg, insertion of shunts, embryo reduction, evacuation of molar pregnancy.)
-Miscarriage, intrauterine death and stillbirth.
-Therapeutic termination of pregnancy.


If rhesus disease is discovered in a foetus how can the anaemia be treated in utero?

Transfuse packed red cells into the umbilical vein.

Only do this from 18 weeks onwards.

Treatment can be repeated every 2weeks, note after 35 weeks delivery is preferable.


What are the other main 2 antibodies which can cause haemolysis in the new born?

Anti c
Anti kell

ABO disease can also commonly cause haemolysis although is not usually as severe.


What is fetal hydrops?

Fetal hydrops is abnormal accumulation of fluid in 2 or more fetal compartments.

Essentially it is oedema in a foetus.


In moderate fetal hydrops what will happen?

In utero:
Products of RBC production are transferred across the placenta to the maternal circulation to be metabolised so there are few problems in utero.

They will have jaundice have a relatively high risk for developing kernicterus (90% mortality + significant morbidity).

Will have a moderate degree of anaemia.


In severe fetal hydrops what will happen?

Severe anaemia with erythropoiesis from liver and spleen..

Pleural effusions.

Ascites and hepatosplenomegaly.

Anasarca (whole body oedema)

Boggy oedematous placenta.


What are the maternal complications of severe fetal hydrops?

Increased risk of pre-eclampsia
Retained placenta


What are the non immune related (e.g. rhesus disease) causes of fetal hydros?

-Idiopathic 60%
-Cardiac abnormalities 20-35%
-Haemolytic diseases (thalassemia major, G6DPH deficiency)
-Twin to twin transfusion