Rhesus isoimmunisation

Question 1

Rh incompatibility

Answer 1

Mother = Rh -ve (15% women)
foetus = Rh +ve

Foetal RBCs enter maternal CVS - mother develops anti-Rh antibodies –> cross palcenta –>< haemolytic anaemia of foetus

Question 2

Sensitising events

Answer 2

TOP
Evacuation of uterus
Ectopic pregnancy
Vaginal bleeding <12 weeks
Invasive uterine procedure e.g. CVs, amniocentesis
Intra-uterine death
Delivery

Question 3

management

Answer 3

Give anti-D at 28 weeks and after ptentially sensitising events (72hrs)

Assess severity:
Doppler of foetal middle cerebral artery, foetal blood smapling to confirm

all babies born to Rh -ve women should have their cord blood tested:

• Coombes test - determines Ab on babies RBC
• Kleihauer test - quantifies amount of foetal RBC in maternal blood (if >5mls, mother requires additional anti-D)

Treat affected foetus - transfusions, UV phototherapy

Postnatal: check FBC, billirubin and Rh group