Thrombocytopaenia in pregnancy

Question 1

What is the most common cause of thrombocytopaenia in pregnancy?

Answer 1

Gestational 75% - dilutional, destruction by the placenta

Question 2

What are the features of gestational thrombocytopaenia?

Answer 2

Common (75%) - Usually 3rd trimester and rarely below count of 70, rarely associated with maternal and neonatal sequellae (benign diagnosis of exclusion), resolves spontaneously

Question 3

What is the incidence of thromobocytopenia in pregnancy?

Answer 3

8-10%

Question 4

What is the second most common cause of thrombocytopaenia in pregnancy?

Answer 4

Hypertensive disorders (PET - usually mild and treatment is delivery, HELLP- may be severe and treatment is delivery and transfusion)

Question 5

What platelet count is suitable for vaginal delivery, operative delivery and epidural?

Answer 5

> 40 vaginal delivery
50 operative delivery including instrumental
80 epidural

Question 6

What are the features of immune thrombocytopaenic purpura?

Answer 6

Autoimmune condition, but diagnosis of exclusion - increased destruction and reduced production of platelets. IgG can pass the placenta and so can affect the neonate. 2/3 are pre-existent before pregnancy

Question 7

What are the pregnancy/ maternal/ neonatal risk factors of immune thrombocytopaenic purpura?

Answer 7

Maternal - bleeding (AP/IP/PP)
Neonatal - intracranial heamorrhage (rare), thrombocytopaenia (up to 37%)
Pregnancy - anaesthesia (no epidural <80), operative delivery not advised <50

Question 8

What treatments might be considered in immune thrombocytopaenic purpura in pregnancy?

Answer 8

> 70 might be no intervention
pre delivery may consider trial of prednisolone
if prednisolone unsuccessful may consider anti D
Rarely splenectomy for refractory ITP
Rarely platelet transfusion

Question 9

What are the features of thrombotic thrombocytopaenic purpura?

Answer 9

Rare condition - microangiopathic haemolysis, low platelets, renal dysfunction, fever, neurological sequellae (headache to coma)

Question 10

How is thrombotic thrombocytopaenic purpura managed?

Answer 10

exchange transfusion

Question 11

What are the features of haemolytic uraemia syndrome?

Answer 11

Usually postnatal, associated with low platelets, renal dysfunction, microangiopathic haemolysis - treatment is usually supportive

Question 12

What are the delivery considerations for a woman with low platelets?

Answer 12

<50 careful consideration to avoid mid cavity delivery, kiwi, rotational delivery as well as FBS and FSE
<80 epidural contraindicated
Inform neonates - cord blood sample at delivery and no IM vit K until platelet count confirmed