VTE in Pregnancy

Question 1

Definiton and Aetiology

Answer 1

Pregnancy is a hyper-coagulable state due to increased levels of clotting factors and reduced fibrinolyisis as a protective factor against haemorrhage at delivery.
There is also venous stasis in the lower limbs due to uterine compression of the IVC during pregnancy.

Question 2

When is the highest risk of a VTE

Answer 2

In the post partum period

Question 3

How can a VTE present?

Answer 3

Deep vein thrombosis (DVT)
Pulmonary embolism (PE)

Question 4

Epidemiology and risk factors

Answer 4

FHx of VTE during pregnancy
Thrombophilia
Immobility or reduced mobility
Obesity: BMI>30
Multiple pregnancy
Age: >35
Smoking
Multiparity: ≥3
Pre-eclampsia
IVF

Question 5

DVT signs

Answer 5

Calf tenderness: localised to the deep venous system distribution
Erythema
Oedema > 3cm difference between symptomatic calf and contra lateral limb - measured 10cm below the tibial tuberosity

Question 6

Symptoms

Answer 6

Leg pain: typically unilateral
Leg swelling

Question 7

PE Signs

Answer 7

Tachypnoea
Tachycardia
Hypoxia
Haemoptysis
Hypotension

Question 8

PE symptoms

Answer 8

Pleuritic chest pain
SOB

Question 9

Diagnosis

Answer 9

Compression duplex USS
CXR
ECG: evidence of right heart strain
GOLD STANDARD FOR PE: CT pulmonary angiography (CTPA)
- CTPA/VQ scan not required in Px with suspected DVT/PE confirmed on Doppler USS

Question 10

Treatment

Answer 10

• FIRST LINE: LMWH = Started immediately before confirming diagnosis if DVT/PE suspected and continued for remainder of pregnancy and >6 weeks postnatally or Tx totalling 3 months (whichever is longer)
• Oral anti-coagulation: Can be switched to warfarin or DOAC following delivery
• Massive PE with haemodynamic instability: Thrombolysis, embolectomy, unfractionated heparin

Question 11

Why is LMWH safe during pregnancy?

Answer 11

Efficacy and safety profile. It doesn’t cross the placenta and therefore poses no risk to the fetus.

Question 12

Prophylaxis

Answer 12

FIRST LINE: LMWH:
= From 28 weeks if there are 3 risk factors
= From first trimester if there are >4 risk factors
= RF should be assessed at booking and postpartum. Prophylaxis continued until 6 weeks postnatally, with temporary pause during labour
SECOND LINE =
- Intermittent pneumatic compression
- Anti-embolic compression stockings

Question 13

Complications

Answer 13

• Recurrent VTE
• Post-thrombotic syndrome
• Chronic thromboembolic pulmonary hypertension