• History
  • Characterise the pain, how it came on, etc. (all usual questions about pain – SOCRATES)
  • Reduction in fetal movements
  • Symptoms of pre-eclampsia: headache, visual disturbance
  • Risk factors for pre-eclampsia: family or personal history, recurrent miscarriages, assisted pregnancy (e.g. IVF), twin pregnancies
  • Risk factors for DVT/PE: clotting disorders in patient or patient’s family, recent travel, unilateral leg swelling
    • Pregnancy itself is a risk factor for DVT/PE due to its hypercoagulable state
    • In pregnant patients, the source of the clot may be in the pelvis and venous thromboembolism must still be considered in the absence of leg swelling or recent travel, especially from the third trimester
  • NB: Don’t ignore small details that don’t fit in with the story – pregnant patients don’t present ‘classically’
    • No single component of the history can be used as a reason not toinvestigate
• Examination
  • Physiological changes of pregnancy must be considered in interpreting examination findings
    • Pregnant women may have a resting tachycardia, tend to feel warm and vasodilated, and are relatively hypotensive – these signs may mask underlying pathology, e.g. sepsis
    • NB: Although pre-eclampsia is classically defined as blood pressure of ³140/90 on ³2 occasions or a 20% increase from baseline, occurring ³20 weeks’ gestation, the absence of hypertension does not preclude a diagnosis of pre-eclampsia
    • Blood pressure profiles may be more useful than a single BP reading
  • Pregnant patients are hyperreflexic in general however sustained clonus should alert you to pre-eclampsia, as well as neurological signs e.g. altered mental state
  • Cardiotocography (CTG) can be used to check fetal movements and fetal heart rate
  • A bedside ultrasound should not distract from examination
    • Mothers lose weight and become sicker before fetal growth is impaired

• Bloods – WCC to rule out pneumonic process, uric acid (if elevated, points to pre-eclampsia), LFT derangement (particularly ALT and AST, rather than obstructive enzymes)
  • In addition to pre-eclampsia, be aware of findings consistent with a diagnosis of HELLP syndrome (Haemolysis, Elevated Liver enzymes, Low Platelet count)
  • Be mindful of how normal findings differ between a pregnant and non-pregnant patient:
    • Pregnant patients have a respiratory alkalosis (baseline VBG PaCO₂ can be 30-32)
    • Pregnant patients can have an elevated alkaline phosphatase (due to placenta)
    • WCC may be marginally elevated (non-specific, in pregnancy)
    • Physiological anaemia of pregnancy (dilutional due to increased blood volume)
    • Increased filtration rate in pregnancy (urea may be 2 and creatinine 40-50 – therefore a creatinine of 70-90 may indicate moderate renal impairment)
• Urine dipstick – check for proteinuria (pre-eclampsia)
• ECG – likely to demonstrate sinus tachycardia but may show right heart strain
• CXR – pneumonic process or pulmonary oedema (peripartum cardiomyopathy)
  • Use appropriate shielding of the fetus
  • Counsel the patient – the minimal amount of radiation in a CXR may avoid the need for further investigation and radiation

If all investigations above are normal and you are considering a PE, what investigation is next?

• Risk stratification methods (e.g. Wells score) have not been validated in pregnant patients
• D-dimers can be elevated in the absence of clots so only a negative d-dimer is helpful
• The decision between a V/Q scan and a CTPA depends mainly on what is available at that time at your institution
• Advantages of V/Q: lower dose of radiation and gives you a sense of mismatch in the lungs
• Advantages of CTPA: more readily available in most centres, gives good idea of the clot load and diagnosis, but administering radiation directly to area around rapidly dividing tissue (breast tissue)
• An echo should be done at some point in the next day, to exclude peripartum cardiomyopathy
• A doppler scan can be done if the skill set to perform one is available
  • A negative Doppler does not exclude a PE
  • Even if the patient has a DVT and needs anticoagulation, further investigations are needed to gain an idea of the clot burden in the lungs

• Therapeutic dosing of low molecular weight heparin (LMWH) is the mainstay of treatment
  • Pregnant patients can’t use warfarin or oral anticoagulants
• Patients can be taught to self-administer 1mg/kg twice daily dosing of enoxaparin at home and cease when they go into labor to ensure they are not in therapeutic range during delivery
• If there is a very high clot load, the patient may be transitioned to a heparin infusion in hospital for the 24 hours before delivery

• Australia’s maternal mortality rate is <10 per 100 000 deliveries
• Pulmonary embolism is still a significant diagnosis which is missed so a high index of suspicion is vital
• Be careful in history taking and risk stratification – tend towards investigating rather than not
• The hypercoagulable state associated with pregnancy exists beyond delivery for about 6 weeks postpartum
  • Be mindful about VTE prophylaxis postpartum and follow up for subsequent pregnancies