VTE

Question 1

VTE in pregnancy - overview

Answer 1

1. Includes DVT and PE
2. Virchow’s triad - all components present in pregnancy. Venous stasis, procoagulant factors increased, vessel wall injury occurring during labour/CS
3. Prothrombotic state aggravated immediately after delivery and resolves gradually over the 6 weeks postpartum
4. 4-5x increased risk c/w non-pregnant women, but absolute risk still low at 2:1000 in pregnancy
5. 1/3 to 1/2 occur postpartum. 1/4 of events are PE, 1/40 of these are fatal. Still one of the most common causes of maternal mortality in the developed world

Question 2

VTE in pregnancy - clinical features

Answer 2

Thrombosis often starts in calf but only thrombosis above knee produces clots large enough to produce a significant risk of PE

DVT

1. Leg pain or discomfort
2. Swelling
3. Tenderness
4. Erythema, increased skin temperature
5. Lower abdominal pain (high DVT)

PE

1. Dyspnoea
2. Collapse (due to large pulmonary embolus)
3. Chest pain (commonly pleuritic)
4. Haemoptysis
5. Tachycardia, tachypnoea, focal chest sign (reduced air entry, friction rub, crepitations), signs and symptoms associated with DVT

Question 3

VTE in pregnancy - ix

Answer 3

In postpartum period, there should be a high level of suspicion for women presenting with any symptoms of VTE. Urgent ix warranted

1. **Dx DVT = Doppler compression U/S

If DVT confirmed or PE suspected:

2. Pulse oximetry
3. ECG
4. CXR
5. CTPA (alternative = V/Q scanning, but fetal radiation dose negligible for both and causes no increased risk of childhood malignancy)

Question 4

VTE in pregnancy - mx

Answer 4

1. Initial tx = therapeutic doses of heparin (does not cross placenta) + rest + analgesia
   - Dalteparin 200 units/kg up to 18000 units SC, daily or 100 units/kg up to 9000 units SC, twice daily
   - Enoxaparin 1.5mg/kg SC, daily or 1mg/kg SC BD
2. Once clinical improvement seen, the woman is encouraged to ambulate and wear compression stockings. Tx continued with SC LMWH. (Is this different to eTG guidelines?) Therapy required for duration of pregnancy + 6 weeks postpartum
3. Around time of delivery, anticoagulation will need to be suspended bc risk of haemorrhage
4. Woman may change to warfarin postpartum
5. Breastfeeding not contraindicated with either heparin or warfarin

Question 5

VTE - next pregnancy and contraception

Answer 5

1. Testing for underlying thrombophilias generally performed after delivery
2. Pts with pregnancy-related VTE advised to have LMWH prophylaxis commencing in early pregnancy and continuing until 6 weeks postpartum
3. Dose depends on estimated risk - most pts can use prophylactic dose therapy while very high-risk women may need more intensive tx

Contraception

4. Women with previous VTE should not receive estrogen-containing contraceptives or HRT
5. Alternate contraception (e.g. IUD) should be considered