Haemolytic Disease of The Foetus and Newborn

Question 1

HDFN

Answer 1

-Transplacental passage of maternal antibodies causing immune haemolysis

Question 2

HDFN Pathogenesis

Answer 2

• Can be naturally occurring
• Most often from alloimmunisation
• Rhesus positive father and rhesus negative mother required for this situation
• Only small amount of foetal blood needed
• Second pregnancy, maternal antibodies fix to foetal red blood cells, recognised as foreign and destroyed
• Can lead to anaemia, heart failure, fluid retention
• Bilirubin initially cleared through placenta, after birth immature liver is not capable

Question 3

HDFN RFs

Answer 3

Traumatic deliveries, manual removal, stillbirths, abdominal trauma, multiple pregnancies
-Hydrops foetal is can be caused by HDFN, mechanism unknown

Question 4

HDFN Presentation

Answer 4

• Picked up on indirect Coombs’ (looks at maternal plasma)

- Infants may appear normal, jaundiced, pallor, hepatosplenomegaly

Question 5

HDFN Differentials

Answer 5

• Other causes of HDN (other antibodies e.g. Rh system, ABO system, Kell)
• Other causes of neonatal jaundice (infections, membranes deficits, haemorrhage)
• Non-immune causes of hydrops foetalis (anaemia, cardiac problems)

Question 6

HDFN Ix

Answer 6

• Indirect Coombs’ should be performed for all rhesus negative mothers
• Antenatal ultrasound (doppler USS of middle cerebral artery has largely replaced foetal blood sampling for detection of foetal anaemia)
• Foetal blood sampling if doppler confirms anaemia
• FBS, biochemical indices
• Postnatal diagnosis
• Immediatley after birth, check baby’s blood type, direct Coombs’ test, haemoglobin and bilirubin

Question 7

HDFN Management

Answer 7

• As soon as anaemia confirmed, transfusion should be commenced with O-
• If complications, delivery early
• After delivery
• 50 percent will be fine but monitor for late onset anaemia
• 25% will have moderate disease and require transfusion
• 25% will have severe disease and either be stillborn or hydrops foetalis
• If severe HDFN suspected, birth should be attended by paediatrician, O- ready, baby to be resuscitated
• Early administration of IVIG for severe cases

Question 8

HDFN Prognosis

Answer 8

Usually very good, poor if hypdrops foetalis

Question 9

HDFN Prevention

Answer 9

-Routine antenatal anti-D prophylaxis for those who have not been sensitised at 28 and 34 or just 28 weeks