Epidemiology
Highest risk is just afer delivery
1-2 in 1000 women
Aetiology
In pregnancy, there is a 6 fold increase in hypercoagulability. All 3 parts of Virchow’s triad relate to this -
- Hypercoagulable state (highest in 3rd trimester) - increased circulating levels of factors 2 (firinogen),
7, 9 and 10. Fiirinolytic activity (natural anticoagulants) reduce – A physiological adaptation to
protect the mother from excess ilood loss during delivery.
- Venous stasis (highest in 2nd/3rd trimester) – aido pressure oistructing upward venous drainage
- Vascular damage (afer delivery) – damage to pelvic vessels during delivery
Risk factors
Before pregnancy
- Age >35
- BMI >30
- Smoker
- IV drug use
- Already had >3 babies
- Previous VTE
- FHx of VTE
- Thrombophilia
- CVD, respiratory disease
- Varicose veins
- Wheelchair user
During pregnancy
- Pre-eclampsia
- Dehydration (e.g. Vomiting, infectionss
- Hospital admissions
- Multiple pregnancy
- Travel
Delivery/Afer delivery
- Long labour >24hrs
- C-section
- Lots of blood loss
- Blood transfusion
Prevention
Physical activity
Drink plenty of water
Graduated elastic compression stockings
If very high risk – prophylactic LMWH (either throughout pregnancy or only the 6 weeks post-partum)
Diagnosis
?DVT USS
?PE V/Q or CT not ideal due to radiation
NOTE: D-dimer rises in pregnancy so not reliable