Preecclampsia

Question 1

Possible aetiology

Answer 1

1. Placenta Ischemia
   - Pregnancies complicated by PET - 2nd wave of trophoblast cell invasion of spiral arterioles is abnormal causing impaired perfusion of placental tissue
   - Spiral arterioles retain intact endothelial and smooth muscle linings and undergo much less than expected dilatation = thought to cause release of factors that may be responsible for placental dysfunction, vasoconstriction and hypertension
2. Endothelial dysfunction
   - Circulating factors released from placenta in response to hypoxia as a result of under perfusion
   - Damage to endothelial cells will:
   . Increased vascular sensitivity to angiotensin II which controls BP
   . Activation of coagulation cascade
   - Increased response to harmful tissue such as hypoxia and larger placental mass
3. Partner specific maladaptations
   Studies indicated that the length of sexual relationship is inversely related to PET
4. Effects of placental ischemia and endothelial disruption
   - Generalised vasoconstriction
   - Increased systemic vascular resistance
   - Increased vascular hydrostatic pressure
   - Decreased tissue hyper fusion
   - Multiple organ dysfunction

Question 2

What are the investigations into PET?

Answer 2

• BP should be checked regularly - if woman becomes hypertensive start hypertensive drugs
• Renal system:
  . Dipstick to measure proteinuria, if more than 1 + then send for MSU
• Haematological system ( PET associated with blood vessel vasoconstriction which can lead to endothelial damage which can cause):
  Blood test which measures:
  . Platelets - reduced highlights endothelial damage
  . Heamocrit - raised levels reflect haemolysis due to breakdown of RBC causing decreased clotting factors
  . DIC - can lead to blood clots inside small vessels
  . Hb - to check levels are ok to deliver
• Hepatic investigations (there can be a corresponding reduction in blood supply in liver due to vasoconstriction)
  This can cause:
  . Discomfort in epigastric area and indigestion which indicates potential vasospasm within liver
  . LFT - abnormal results (raised ALT/AST)
• Neurological
  . Symptoms of PET = frontal headache caused by decreased perfusion and abnormal electrical activity caused by local cerebral vasospasm
  . Deep tendon reflex can be tested to asses function of sensory pathway