Haemolytic disease of the newborn

Question 1

Define haemolytic disease of the newborn?

Answer 1

An immunological condition that occurs when a rhesus negative mother is sensitised to rhesus positive blood cells of baby in utero

Question 2

What is the basic pathology of haemolytic disease of the newborn?

Answer 2

Rhesus neg mam sensitised to rhesus pos baby - maternal antibodies cross placenta
Destroy foetal red blood cells = haemolysis, anaemia and hyperbilirubinaemia
Can also be caused by other blood group incompatabilities

Question 3

What is the epidemiology of haemolytic disease of newborn?

Answer 3

Rare due to prophylatic anti-D immunoglobulin prophylaxis
Without prophylaxis occurs in 16% Rh-neg mothers

Question 4

What are the sensitisation events for haemolytic disease of the newborn?

Answer 4

From current or previous pregnancy - must allow for foetal blood to cross into maternal circulation
Delivery
Trauma
invasive procedures
Miscarriage

Question 5

What are the antenatal signs of haemolytic disease of the newborn?

Answer 5

Oedema (hydrops fetalis)
Ascities
Hepatosplenomegaly

Question 6

What are the signs of haemolytic disease of the newborn in neonates?

Answer 6

Juandice within 24hrs of birth
Pallor due to anaemia
Hepatosplenomegaly
Lethargy, poor feeding and irritability
Severe cases = heart failure or kernicterus

Question 7

What bedside investigations should be done for haemolytic disease of the newborn?

Answer 7

Foetal monitoring - Doppler ultrasound is used to assess MCA peak systolic velocity -> foetal anaemia.

Antenatal ultrasound -> assess for hydrops fetalis or signs of foetal anaemia.

Question 8

What maternal bloods can be done for haemolytic disease of the newborn?

Answer 8

Maternal blood group and antibody titre levels
Kleihauer-betke test - quantify foetomaternal haemorrhage

Question 9

What neonatal blood can be done for haemolytic disease of the newborn?

Answer 9

FBC - anaemia
Blood group and direct coombs test - direct antiglobulin test
Serum bilirubin and reticuloctye count
LFTs.

Question 10

What is the antenatal management for haemolytic disease of the newborn?

Answer 10

Anti-D immunoglobulin prophylaxis - to all Rh- mothers at 28w and within 72hr of delivering/sensitising events
Foetal anaemia - treated with intrauterine transfusion if detected.

Question 11

What is the post natal management for haemolytic disease of the newborn?

Answer 11

Phototherapy - to manage jaundice by breaking down unconjugated bilirubin
Exchange transfusion - for severe anaemia or hyperbilirubinemia
IV immunoglobulin - to reduce antibody-mediated haemolysis in neonates.

Question 12

What follow-up is required for haemolytic disease of the newborn?

Answer 12

Check for late onset anaemia at around 4-6w (consider folate supplements to prevent this)
Hearing screen
Parent counselling on risk of recurrence in future pregnancies.

Question 13

What are the long-term complications of haemolytic disease of the newborn?

Answer 13

Neurological sequelae, including hearing loss, cerebral palsy or developmental delays.