Rhesus Incompatibility Flashcards
What do rhesus-D positive women require when pregnant?
No additional treatment
What can happen in a rhesus-D negative mother?
Theres a change her baby might be rhesus-D positive.
During the pregnancy the mothers blood can come into contact with the babies rhesus-D positive blood and the mother will produce antibodies.
What problems can rhesus-D antibodies cause during pregnancy?
Theres usually no problem with the first pregnancy because the mother hasn’t previously been exposed or built up antibodies.
During subsequent pregnancies the mothers antibodies can cross the placenta into the foetus.
If the foetus is rhesus-D positive, these antibodies will attack the babies blood and cause haemolysis.
What disease can babies get?
Haemolytic disease of the new born
What is the management?
Anti D injections to rhesus negative women.
Why is prophylaxis so important?
Because theres no way to reverse the sensitisation process once it has occurred.
How does anti-D injections work?
The anti-D medication attaches itself to the rhesus-D antigens on the babies red blood cells and destroys them before the mum can recognise them and create antibodies against them.
It prevents the mother from becoming sensitised to the rhesus-D antigen.
When are anti-D injections given?
Routinely:
28 weeks gestation
at birth
Extra:
antepartum haemorrhage
amniocentesis procedures
abdominal trauma
*Within 72hrs of a sensitisation event
What is the kleihauer test?
Checks how much foetal blood has passed into the mothers blood during a sensitisation event.
Its used after sensitisation events that occur after 20 weeks.
How does the kleihauer test work?
acid is added to a sample of the mothers blood. The foetal blood is more resistant than the mothers to acid so - foetal haemoglobin will remain fine and mothers haemoglobin will be destroyed.
So you can see how much foetal haemoglobin there is.
