Antenatal venous thromboembolism

M R C O G PA R T 2 · S O S P O C K E T C A R D · K N O W L E D G E A R E A 5 – A N T E N ATA L C A R E

Antenatal Venous Thromboembolism Crosby DA et al. Antenatal venous thromboembolism. TOG 2021;23:206–212. doi:10.1111/tog.12744

1:1000 5–60× 90% ABSOLUTE VTE RATE IN PREGNANCY RISK VS NON-PREGNANT (ANTENATAL– WOMEN WITH PE WHO HAVE RISK FACTORS POSTPARTUM)

DO N' T-M IS S FA C TS

  1. VTE risk: 5-fold ↑ in pregnancy, 20–60-fold ↑ in first 3 months postpartum; absolute rate ~1:1000 pregnancies

  2. On clinical suspicion of DVT, start treatment-dose LMWH immediately, before confirmatory duplex ultrasound

  3. A negative D-dimer does NOT exclude VTE in pregnancy – do not order indiscriminately

  4. Warfarin and DOACs are contraindicated antenatally – treatment of choice is subcutaneous LMWH

  5. No thrombophilia screen at time of acute diagnosis (thrombus distorts results)

  6. Continue therapeutic LMWH until delivery + minimum 6 weeks postnatal + total ≥3 months treatment

  7. Stop LMWH 24 hours pre-delivery; withhold ≥4 hours post-spinal/epidural removal

  8. LMWH/warfarin safe in breastfeeding (warfarin not before day 5); DOACs avoided in pregnancy & breastfeeding

DIAGNOSTIC PATHWAY SNAPSHOT

DVT signs + suspected PE → duplex first; DVT+ = PE assumed No DVT signs / duplex negative → V/Q or CTPA

ABBREVIATION KEY

VTE — venous thromboembolism CTPA — computerised tomography pulmonary angiogram

DVT — deep vein thrombosis V/Q — ventilation/perfusion (scan)

PE — pulmonary embolism MWS — modified Wells score

LMWH — low-molecular-weight heparin RGS — revised Geneva score

UFH — unfractionated heparin HIT — heparin-induced thrombocytopenia

IVC — inferior vena cava APH — antepartum haemorrhage

MDT — multidisciplinary team PPH — postpartum haemorrhage

RCOG — Royal College of Obstetricians & Gynaecologists IJV — internal jugular vein

ECG — electrocardiogram DOAC — direct oral anticoagulant

ABG — arterial blood gas

Source: The Obstetrician & Gynaecologist (TOG), RCOG journal — Crosby DA et al. Antenatal venous thromboembolism. TOG 2021;23:206–212. doi:10.1111/tog.12744

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