Thromboembolism (blood clots) during and after pregnancy

  • Deep vein thrombosis (DVT) is a clot in the deep veins of legs or pelvis, usually with leg swelling and pain, sometimes redness and warmth
    • In pregnant women DVT most often occurs in the left leg
  • Parts of the clot may embolise (break off) and travel through blood vessels to the lungs — a clot in the lung is a pulmonary embolus (PE)

Risk factors (strong risk factors in bold) include

  • Pregnancy — highest risk after birth, can also happen during pregnancy or birth
  • Previous DVT or PE, except if it was a single event related to a major surgery
  • Known condition with thrombophilia (increased tendency to clot)
  • Family history of clots in a first-degree relative
  • Obesity (BMI more than 30)
  • Age more than 35 years
  • Recent surgical procedure (eg caesarean section, appendicectomy)
  • Immobility (eg lower limb injury, long distance travel)
  • Current preeclampsia
  • Smoking
  • Multiple pregnancy
  • In vitro fertilisation (IVF)
  • Transient risk factors (eg dehydration, sepsis)

Ask

  • Ask all pregnant women and check file notes for history of DVT, PE or thrombophilia (clotting disorder)

Check

  • If woman has multiple risk factors OR previous DVT or PE, or known thrombophilia — medical consult
    • Refer to obstetrician or physician as soon as possible
    • Consider DVT prophylaxis (treatment to prevent clots) in this pregnancy
  • Look for red flag symptoms of DVT or PE at every visit during and after pregnancy

Do

  • If you suspect DVT or PE — urgent medical consult 
    • Send to hospital to confirm diagnosis and start treatment
    • Usually treat with low molecular weight heparin (eg enoxaparin) subcutaneous injections during pregnancy
    • May also treat with warfarin tablets — not during early pregnancy
  • All women with DVT or PE in current or previous pregnancies must plan to birth in hospital

While waiting for evacuation

  • Do not lie woman flat on her back. Sitting upright may be best

Check

  • Calculate REWS — AVPU, RR, O2 sats, pulse, BP, Temp
  • Weight, BGL 

Do

  • Give oxygen to
    • target O2 sats 94–98%
    • OR if moderate/severe COPD 88–92%
  • Put in IV cannula — largest possible, insert 2 if time
  • Give other treatment as directed by doctor,  eg pain relief, medicine to stop clots
  • Reassure woman and keep her calm. Have someone stay with her if possible

Follow-up after birth

  • Do not give combined oral contraceptive pill to woman with history of DVT or PE
    • Other hormonal contraception may be suitable after medical consult 
  • Emphasise importance of continuing anticoagulant treatment for whole time as advised by doctor
    • Treatment needs to continue for 3–6 months after birth
  • Reassure her that breastfeeding is not affected by anticoagulation medicines