Vasa Praevia

Question 1

Define Vasa Praevia.

Answer 1

Foetal vessels course through/near membrane over the internal cervical os and below foetal presenting part, unprotected by placental tissue or umbilical cord.

Question 2

What is the major consequence of vasa praevia?

Answer 2

Benckaiser’s haemorrhage = the haemorrhage of blood when the vessels are ruptured as baby descends

Question 3

What are the types of vasa praevia?

Answer 3

• Type 1 VP = velamentous cord insertion in a single or bilobed placenta
• Type 2 VP = foetal vessels running between lobes of a placenta with 1 or more accessory lobes

Question 4

What are the risk factors for vasa praevia?

Answer 4

• Foetal anomaly (bilobed placenta or succenturiate lobes)
• History of low-lying placenta in 2^nd trimester
• Multiple pregnancies
• IVF

Question 5

What are the signs and symptoms of vasa praevia?

Answer 5

• ROM → fresh PV bleeding + foetal bradycardia
  
  • After the membranes rupture, the veins alone can’t hold the weight of the baby → bleeding
• Foetal HR abnormalities – decelerations, bradycardia, sinusoidal trace, foetal demise
• O/E - palpable vessels in the membranes
• Amnioscope can directly visualise this

Question 6

What are the appropriate investigations for suspected vasa praevia?

Answer 6

• Kleihauer test
• Haemoglobin electrophoresis – identify if foetal or maternal blood
• Doppler USS

Question 7

What is the management of vasa praevia?

Answer 7

C-section

Question 8

What are the complications of vasa praevia?

Answer 8

• No major maternal risk but dangerous for the foetus
  
  • A relatively small amount of blood loss to a foetus has major implications for the foetus
    
    • Rapid delivery + aggressive resuscitation including use of blood transfusion if required are essential
• Prognosis
  
  • Presenting with haemorrhage = 60%
  • Antenatally = 3%