Thrombo-embolic disorders

Question 1

What are the thrombo-embolic disorders that could occur with pregnancy?

Answer 1

• DVT -> 75% occur antepartum (popliteal vein)
• PE -> 40-60% occur post partum (left pulmonary artery) -> 15% fatality

Question 2

Why is pregnancy associated with increased tendency for blood clotting?

Answer 2

Virchow’s triad

• Stasis: due to abnormal blood flow
• Endothelial damage: during pregnancy & delivery
• Hyper-coagulability
  -> increased production of clotting factors: VII, VIII, X, Von Willebrand’s, & fibrinogen
  -> decreased anti-coagulants: Protein S & anti-thrombin
  -> decreased fibrinolytic activity: increased plasminogen activation inhibitor

Question 3

What are the risk factors for TED with pregnancy?

Answer 3

• maternal age > 35 years
• multi-parity 5 or more
• BMI > 30
• infections
• Pre-eclampsia
• immobility
• pelvic or leg trauma
• heavy smoking
• atrial fibrillation
• personal or family history of TED
• thrombophilia
• anti-phosphilipid antibodies & lupus anticoagulants
• operative delivery
• previous history of IUFD, early pre-eclampsia, IUGR, abruption

Question 4

What is the commonest form of venous thrombosis in pregnancy?

Answer 4

Superficial thrombophlebitis
- occurs in 1% in existing varicose veins
- redness around vein is a reaction to blood clot

Question 5

How is superficial thrombophlebitis diagnosed?

Answer 5

Clinically:
- tenderness
- erythema
- palpable cord-like vein
- pain

Question 6

How is superficial thrombophlebitis treated?

Answer 6

symptomatic treatment
- compression bandage
- leg elevation
- encourage mobility

exclude DVT

Question 7

What are the clinical features for DVT?

Answer 7

• pain
• local tenderness
• swelling
• change in skin color & temperature
• Homan’s sign

Question 8

What is the prognosis of a calf DVT?

Answer 8

• 75-80% are benign
• 20-25% spread to involve proximal deep veins -> 50% risk of PE

Question 9

What are the symptoms of a proximal (ilio-femoral) DVT?

Answer 9

involves entire limb
- pain
- swelling
- blue & warm (unimpaired arterial supply)
- pale & white (impaired arterial supply)

Question 10

What investigations are preformed for DVT?

Answer 10

• Duplex ultrasonography: 97% specificity
• MRI: 100% in NON pregnant ladies
• D-dimer is not useful in pregnancy cause it normally increased with gestational age

Question 11

What is the rate of maternal mortality from PE?

Answer 11

if untreated -> 13% within the first hour

Question 12

What is the clinical picture of a pulmonary embolism?

Answer 12

• dyspnea
• tachypnea
• tachycardia
• haemoptysis
• pleuritic chest pain
• cyanosis
• pyrexia
• syncope/shock

Question 13

How should PE be managed?

Answer 13

1- Start treatment immediately -> SC LMWH
2- Then investigate
- chest x-ray
- ECG
- ABG: acidosis
- compression duplex doppler
- CT angiography

Question 14

What are the risks of radiological exposure to fetus?

Answer 14

radiation exposure of up to 0.05Gy (5 rad) in utero
- 1.2 - 2.4 -> oncogenicity relative risk
- 0.1% risk of absolute malignancy

Question 15

How is the acute phase of TED treated in pregnancy?

Answer 15

1- IV or SC LMWH -> aPTT 2 - 2.5 control for 1 week
2- continue prophylaxis for 6 - 12 weeks postpartum (for PE 4-6 months)
3- elevate legs
4- graduated elastic compression stockings -> reduce edema
5- inferior vena cava filter -> in recurrent PE
6- thrombolytic therapy is teratogenic so only done if life saving (streptokinase & rivaroxaban)
7- thoracotomy & embolectomy

Question 16

What are the complications that may arise with long term heparin therapy?

Answer 16

1- overdose -> reversed by protamine sulfate
2- osteoporosis
3- thrombocytopenia

monitor platelet count regularly

Question 17

Why is Warfarin contraindicated in pregnancy?

Answer 17

it causes Fetal Warfarin Syndrome
- nasal hypoplasia
- depressed nasal bridge
- irregular bone growth
- intracranial fetal hemorrhage

Question 18

What are the causes of thrombophilia?

Answer 18

INHERITED
- hyperhomo-cysteinemia mutation
- factor-V Leiden mutation
- mutation in prothrombin & prothrombin-II
- protein S
- protein C

ACQUIRED
- antiphospholipid syndrome
-> lupus anticoagulants antibodies
-> anticardiolipin antibodies

Question 19

What is the clinical criteria for anti-phospholipid syndrome diagnosis?

Answer 19

1- Thrombosis -> 1 or more confirmed episodes of venous, arterial, or small vessels disease
2- unexplained recurrent pregnancy loss
3- pre-eclampsia or placental insufficiency occurring < 34 week
4- unexplained IUFD

Question 20

What is the laboratory criteria for antiphospholipid syndrome?

Answer 20

• medium or high titer IgG or IgM anticardiolipin antibody
• lupus anticoagulant on 2 or more occasions at least 6 weeks apart
• aPTT is prolonged & not correctable by mixture with normal plasma

Question 21

How is antiphospholipid syndrome treated?

Answer 21

low dose aspirin + heparin

Question 22

The combination of aspirin + LMWH is effective in what cases?

Answer 22

1- recurrent fetal loss in APS
2- inherited thrombophilia
3- history of severe pre-eclampsia
4- IUGR
5- abruptio placentae
6- recurrent fetal loss

Question 23

What are the risk factors for an amniotic fluid embolism?

Answer 23

• maternal age > 30
• multiparity
• complicated labour

occurs during labour or shortly after delivery & is life-threatening

Question 24

What are the clinical features for a amniotic fluid embolism?

Answer 24

Acute onset of
- respiratory collapse
- cardiovascular collapse
- altered consciousness
- features of DIC
- multi-organ dysfunction
- fetal bradycardia

Question 25

How is the diagnosis of amniotic fluid embolisms made?

Answer 25

• ABG -> respiratory acidosis
• CBC -> anemia, thrombocytopenia
• Coagulation studies -> prolonged PT

Question 26

How is an AFE treated?

Answer 26

1- correct hypoxia -> high flow O2 or intubation
2- correct hypotension/shock -> vasopressors
3- correct anemia & coagulopathy -> platelets, FFP, PRBCs
4- emergency C-section