Thromboprophylaxis

Question 1

What changes occur in pregnancy in blood?

Answer 1

Venous stasis
Trauma to pelvic veins at delivery

Procoagulant changes:
Higher levels of factors X, CIII and fibrinogen
Reduced endogenous anticoagulation activity (protein C, S and antithrombin III)
Reduction in protein S activity

Pregnancy is a risk factor for VTE

Question 2

What are high risk factors for VTE?

Answer 2

History of >1 VTE
Unprovoked or oestrogen related VTE
Single provoked VTE + thrombophilia or FHx
Antithrombin III deficiency

Question 3

What are intermediate risk factors for VTE?

Answer 3

Thrombophilia but no VTE
Single provoked VTE
Medical comorbidities e.g. cancer, inflammatory, carina, respiratory, SLE, sickle cell, nephrotic syndrome
IVDU
Antenatal surgery

Question 4

What other risk factors for VTE?

Answer 4

Age > 35 
Obesity
Parity 3 or more
Smoker
Large varicose veins
Current infection
Pre-eclampsia
Immobility
Dehydration
Multiple pregnancy
Assisted reproduction techniques (IVF pregnancy)

IF 3 - prophylaxis from 28 weeks until 6wks postnatal
If 4+ - immediate to 6 weeks postnatal

Question 5

What should you give for VTE prophylaxis in pregnancy?

Answer 5

LMWH - antenatally to 6 weeks postpartum

Does not cross placenta too large

Question 6

What are indications for VTE prophylaxis?

Answer 6

Risk assessment at booking:
High risk factors
Intermediate risk factors

Emergency LSCS - 7 days postpartum LMWH

Question 7

When can enoxaparin be given postnatally?

Answer 7

ASAP
As long as no ongoing PPH
>4h since epidural sited or removed

Question 8

What are clinical feature of DVT?

Answer 8

Leg swelling 
Pain
Redness
Tenderness
Pyrexia
ERythema
Oedema

Question 9

What are clinical features of PE?

Answer 9

SOB
Chest pain
Haemoptysis
COlpase

Signs of DVT

Pleural rub
Fine crepitations

Hypoxic
Tachypnoea

Massive PE:
Hypoxia
Hypotension
Tachycardia
Collapse

Question 10

What investigations in DVT/PE?

Answer 10

Bedside:
BP, ECG (right heart strain), SaO2, Temperature

Bloods:
FBC
U&E
LFT
Clotting screen
Thrombophilia screen
ABG
D-dimer - if negative likely no VTE, if positive - means nothing 

Imaging:
CXR
DVT: Duplex US of deep veins
PE: CTPA
VQ scan

Question 11

What is management for VTE?

Answer 11

LMWH - continue for 6 months and 6 weeks postpartum
Consider switching to warfarin post-delivery (safe in breastfeeding)

May need thombolysis or percutaneous catheter intervention

Question 12

How should VTE be managed in labour?

Answer 12

Stop LMWH
Keep well hydrated
Avoid regional anaesthesia (spinal/epidural) until at least 12h after last dose of prophylactic and 24h after therapeutic LMWH
Wait >4h until epidural catheter removed until next dose
Do not remove catheter until >12h after last dose