VTE in pregnancy Flashcards
What are the physiological changes of pregnancy that predispose to VTE
Venous stasis, trauma, hypercoagulability
Hypercoagulable
Physiological hypercoagulable state:
Increase in clotting factors, fibrinogen, PAl-1 (plasminogen activator inhibitor)
Decrease in protein S and antithrombin
Venous stasis
weight of uterus on the IVC → venous stasis (therefore more likely on the left hand side)
Which medical disorders contribute to VTE risk in pregnancy
Thrombophilia (hereditary):
- Deficiency in protein C/S/AT-III
- Abnormalities in procoagulants
- factor V leiden
- Prothrombin mutation
Acquired thrombophilia: anti-phospholipid syndrome
What are the features of antiphospholipid syndrome and how is it managed
Miscarriages (≥3) + lupus anticoagulant or anticardiolipin antibodies
- Adverse pregnancy outcomes – 3+ consecutive miscarriages before 10 weeks of gestation
- 1 or more morphologically normal foetal losses after 10w of gestation
- 1 or more preterm birth before 34-weeks of gestation
Treat with (unfractionated) heparin and aspirin → dramatically improved outcomes
It may be associated with SLE or other autoantibody disorders
When is VTE is most likely to occur in pregnancy
Most commonly in the post-partum (puerperal) period and first trimester
What are the risk factors for VTE in pregnancy
Pre-existing:
- Maternal age > 35 years
- Thrombophilia
- Obesity (> 80kg, BMI >25)
- Previous VTE
- Severe varicose veins
- Smoking
- Malignancy
- FHx of unprovoked VTE
Pregnancy-related
- Multiple pregnancy
- Pre-eclampsia
- Grand multiparity (>3)
- Caesarean section (especially if emergency)
- Damage to pelvic veins
- Sepsis
- Prolonged bed rest, travel (> 4 hours)
- IVF pregnancy
How much more likely is a pregnant woman to get VTE than a non-pregnant woman
6-10x
What are the symptoms and signs of DVT in pregnancy
Calf pain
Swelling
Abdominal pain
Unilateral, erythematous, swollen, warm, tender calf
(+cardioresp exam + obs)
What are the symptoms and signs of PE in pregnancy
SOB, dyspnoea
Chest pain (on inspiration, pleuritic - sharp, worse lying down)
Haemoptysis
Tachycardia
Mild pyrexia
(+cardioresp exam + obs)
What investigations should be done for VTE in pregnancy
Bedside: ECG (S1Q3T3)
Bloods: FBC, ABG, U&Es, LFTs, coagulation
Other
- Doppler USS legs
- CXR (If doppler -ve)
- CTPA (if CXR abnormal)
- Echo (if unstable)
- V/Q scan (Doppler and CXR normal)
- Venography
Stable
1. Doppler USS legs
- Doppler +ve: start LMWH
- Doppler -ve: CXR
2. CXR
- CXR normal: V/Q scan
- CXR abnormal: CTPA
3. V/Q scan
- V/Q scan +ve: Start LMWH
- V/Q scan -ve: CTPA
4. CTPA
- CTPA +ve: thrombolysis, start LMWH
- CTPA -ve: stop anticoagulation
Unstable
Portable echo
What is the management for DVT in pregnancy
- A-E assessment and involve senior + MDT + haematologist
- SC LMWH e.g. clexane
- Elevate the leg
- TED stockings
+ maintenance
What is the management for PE in pregnancy
- A-E assessment and involve senior + MDT + haematologist
- SC LMWH e.g. clexane
+ maintenance
What is the management for massive PE in pregnancy
- A-E assessment and involve senior + MDT + haematologist
- IV unfractionated heparin (thrombolysis)
- thrombolytic therapy
- thoracotomy
- surgical embolectomy
+ maintenance
What is the maintenance treatment for VTE
Treatment with therapeutic doses of SC LMWH should be continued for the remainder of the pregnancy and for at least 6 weeks postnatally and until at least 3 months of treatment in total
- Measure Anti-Xa if at extremes of body weight or there are complicating factors
Wear TED stockings for 2 years following DVT to prevent post-thrombotic syndrome
Why can’t warfarin be used in pregnancy
First trimester: teratogenic
third trimester: foetal intracranial haemorrhage
What are the indications for anticoagulation in labour and delivery + anaesthetic considerations
VTE occurs at term: IV unfractionated heparin → continue treatment for at least 3 months
LMWH maintenance therapy: do NOT inject any more at labour
Planned delivery: discontinue LMWH 24h prior (12h if prophylactic dose)
Anaesthetic:
- Regional i.e. epidural: must wait 24h until AFTER the last dose of LMWH
- Spinal: must wait 4h AFTER use of spinal anaesthesia or removal or epidural catheter
High haemorrhage risk: IV unfractionated heparin