Haematology - Obstetric Haematology

Question 1

How is anaemia formed during pregnancy?

Answer 1

Volume expansion of blood leads to increased cardiac output and therefore a dilutional anaemia

Question 2

Why is there an increased risk of VTE during pregnancy?

Answer 2

Woman is in hypercoagulable + hypofibrinolytic state

Question 3

What happens to different blood factors during pregnancy?

(Plasma volume, RBC mass, Hb, MCV, Hct, Plts, WCC, Fx VII, VIII, IX, X, XII, XI + Protein S)

Answer 3

• Plasma voume: Increases
• RBC mass: increases
• Hb: Decreases
• MCV: Increass
• Plts: Decreases
• WCC: Increases
• Fx VII, VIII, IX, X, XII: Increases
• Fx XI: Decreases
• Protein S: Decreases

Question 4

What is HELLP Syndrome and its key features

Answer 4

Haemolysis, Elevated liver enzymes, Low platelets
- Life-threatening complication a/w pregnancy

Key features:
- MAHA
- Increased AST + ALT
- Decreased platelets
- Normal APTT + PT

Question 5

What are some differentials for HELLP syndrome?

Answer 5

• DIC (Increased APTT + PT, decreased fibrinogen)
• AFLP (marked transaminitis)

Question 6

What is the management of HELLP syndrome?

Answer 6

• Supportive
• Delivery of foetus

Question 7

How is haemolytic anaemia of the newborn formed?

Answer 7

• Red cell Ab production through foetal cells entering woman’s circulation during pregnancy/delivery
• High maternal Ab levels can destroy foetal RBCs if they have corresponding RBC Ag
• IgG mediated (only IgG can cross the placenta)

Question 8

What are some features of haemolytic anaemia of the newborn?

Answer 8

• Foetal anaemia
• Jaundice
• Kernicterus
• Hydrops foetalis

Question 9

What Ab is most responsible for haemolytic disease of the newborn and what are some other Abs?

Answer 9

• Anti-D (Most responsible = always transfuse RhD negative blood to RhD negative women of childbearing age)

Others:
- Anti-C
- Anti-K
- IgG ABO

Question 10

How is haemolytic disease of the newborn monitored?

Answer 10

MCA (middle cerebral artery) doppler ultrasound

Question 11

How is Anti-D formation prevented?

Answer 11

• Rhd Negative women
• Mother given IM anti-D Ig when at high risk of foeto-maternal haemorrhage
• Routine antenatal prophylaxis at 28 + 34wks
• Given within 72hours of a sensitising event occuring
• Given at delivery if baby is RhD positive

Question 12

What sensitising events require Anti-D Ig?

Answer 12

• Abortion
• Miscarraige
• Abdominal trauma
• ECV
• Amniocentesis