2017 71 Inherited Bleeding Disorders

Question 1

Give a list of inherited bleeding disorders!

Answer 1

1. Haemophilia A & B
2. von Willebrand disease
3. Factor XI deficiency
4. Rare clotting deficiencies: fibrinogen, factors II, V, VII, X, XI, XIII, combined V & VIII
5. Congenital deficiency of vitamin K-dependent factors
6. Fibrinogen disorders
7. Platelet function disorders: Bernard Soulier syndrome, Glanzmann’s thrombasthenia

Question 2

** What is the definition of haemophilia? **

Answer 2

1. X-linked condition
2. A: reduced or absent factor VIII
3. B: reduced or absent factor IX
4. Causing bleeding symptoms

Question 3

** What is the definition of haemophilia? **

Answer 3

1. X-linked condition
2. A: reduced or absent factor VIII
3. B: reduced or absent factor IX
4. Causing bleeding symptoms

Question 4

** How should haemophilia inheritance be assessed? **

Answer 4

1. Family tree to assess likely carrier-ship
2. Genetic testing for likely female carriers

Question 5

** What proportion of neonatal males with severe haemophilia have no previous family history? **

Answer 5

50%

Question 6

** In newborn males with severe haemophilia, what is the chance of the mother being the carrier? **

Answer 6

90%

Question 7

** What are the risks to female carriers of haemophilia? **

Answer 7

1. Low factor VIII or IX levels
2. Increased bleeding with invasive procedures, termination, spontaneous miscarriage, birth

Question 8

What are the risks for male neonates with haemophilia?

Answer 8

1. Intracranial haemorrhage
2. Extracranial haemorrhage
3. Iatrogenic bleeding

Question 9

What are the options for prenatal diagnosis of inherited bleeding disorders?

Answer 9

1. PGD
2. Free fetal DNA for sex determination from 9/40
3. CVS at 11-14/40 if male fetus at risk
4. 3rd trimester amnio if not previously determined

Question 10

When should maternal factor VIII & IX be checked for haemophilia carriers?

Answer 10

1. Booking
2. Before any antenatal procedure
3. In the 3rd trimester?

Question 11

What is the common impact of pregnancy on factor VIII & IX levels?

Answer 11

VIII: rises
IX: stable

Question 12

What factor VIII/IX levels are needed to cover surgical or invasive procedures, or miscarriage?

Answer 12

0.5 units/ml
Aim > 1.0

Question 13

What drugs can be useful in antenatal management of haemophilia carriers?

Answer 13

1. TXA
2. Desmopressin to raise factor VIII levels
3. Recombinant factor VIII
4. Recombinant factor IX

Question 14

What obstetric interventions should be avoided for known or suspected fetus with haemophilia?

Answer 14

1. ECV
2. Ventouse
3. Midcavity forceps
4. FBS
5. FSE

Question 15

What factor VIII & IX levels are needed for insertion & removal of epidural or spinal, and IM injection?

Answer 15

0.5 Units/ml

Question 16

For how long should factor VIII & IX levels be maintained > 0.5 units/ml after birth?

Answer 16

Uncomplicated vaginal: 3 days
CS or instrumental: 5 days

Question 17

What is the recommendation for neonatal testing of babies born to haemophilia carriers?

Answer 17

Male:
Cord blood sampling
Diagnostic testing
Retest at 3-6 months
Female:
No testing

Question 18

How should ICH be excluded in neonates with haemophilia?

Answer 18

Cranial US
Cranial MRI if S&S, even if US normal

Question 19

What are the classifications of von Willebrand disease?

Answer 19

Type 1: partial quantitative
Type 2: qualitative
Type 3: severe quantitative

Question 20

What is the inheritance pattern of von Willebrand disease?

Answer 20

Autosomal
Variably dominant & recessive
Variable penetrance & expression