Overview

• Thrombosis occurs in hyper-coagulable states, such as pregnancy.
• PE risk is very high in postpartum period (HIGHEST RISK TIME PERIOD), hence VTE prophylaxis is crucial.
• Risk Factors → smoking, parity ≥3, age >35, BMI >30, reduced mobility, multiple pregnancy, pre-eclampsia, varicose veins, immobility, FH of VTE, thrombophilia, IVF pregnancy.

Making Diagnosis

Clinical Features

• DVT → unilateral calf/leg swelling. May have dilated superficial veins, tenderness to calf, oedema and colour changes to leg.
• PE → SOB, cough, pleuritic chest pain. Also hypoxic, tachycardic, raised respiratory rate.

Investigations

• VTE risk assessment at booking and again after birth.
• DVT → compression duplex ultrasonography (no radiation exposure).
  • If patient has features of a DVT, they should undergo a duplex ultrasound scan to confirm the presence of a DVT as this does not involve exposing patient to radiation (unlike CTPA/VQ).
  • If ultrasound is negative and a high level of clinical suspcion exists, anticoagulant treatment should be discontinued but the ultrasound repeated on days 3 and 7.
• PE → in A&E: ECG and CXR.
  • +ve signs of DVT → compression duplex USS. If confirms presence of DVT, no further investigation necessary.
  • -ve signs of DVT → CTPA or V/Q.
    • CTPA → increased risk of maternal breast cancer.
    • VQ → increased risk of childhood cancer.
  • RCOG → patients with no sign of DVT and normal CXR, should have a V/Q scan to diagnose PE.

<aside> 💡 Any signs or symptoms suggestive of VTE → objective testing and treatment with LMWH (until the diagnosis is excluded).

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Management Plan

• Prophylaxis → low molecular weight heparin (enoxaparin) + elastic compression stockings.
  • 3 Risk Factors → start at 28 weeks. (2 minor risk factors → 10 days postpartum, but not during pregnancy).
  • ≥4 Risk Factors or Previous VTE Event → start immediately (ie. from booking).
  • Temporarily stop 24 hours before delivery to decrease risk of PPH.
  • Continue until 6 weeks postnatal (+ ensure minimum 3 months in total, inc. antenatally).
    • Continue for 3 months if diagnosis of DVT is made.
    • (If confirmed VTE in pregnancy → treat with TREATMENT DOSE LMWH for remainder + 6 weeks postnatally + minimum of 3 months)
  • If at extremes of body weight (<50kg or >90kg) or renal impairment → monitor via anti-Xa.
• Delivery → temporarily discontinue LMWH 24 hrs before delivery. Epidural not given until at least ≥24 hrs after last dose of LMWH.