Amniotic fluid embolism

Question 1

What is an amniotic fluid embolism?

Answer 1

A rare cause of maternal collapse

Often fatal

Question 2

What is the incidence of amniotic fluid embolism?

Answer 2

2 in 100000

Question 3

What causes amniotic fluid embolism?

Answer 3

Under debate
Strong uterine contractions
Excessive amniotic fluid
Disruption of the vessels supplying the uterus

Question 4

List some risk factors for amniotic fluid embolism

Answer 4

Multiple pregnancy
Increased maternal age
Induction of labour
Uterine rupture
Placenta praevia
Placental abruption
Cervical laceration 
Eclampsia
Polyhydramnios
C-section/instrumental delivery

Question 5

What is the physiology of amniotic fluid embolism similar to?

Answer 5

Anaphylaxis or severe sepsis

Question 6

How is amniotic fluid embolism characterised?

Answer 6

Sudden onset

• hypoxia/respiratory arrest
• hypotension
• foetal distress
• seizures
• shock
• confusion
• cardiac arrest
• Disseminated intravascular coagulation

Question 7

What investigations should be done for amniotic fluid embolism?

Answer 7

Bloods - FBC, U&Es, calcium, magnesium, clotting, ABG
CXR - pulmonary oedema
ECG - ischaemic changes

Question 8

Describe the management of amniotic fluid embolism

Answer 8

ABCDE approach
High flow O2 fluids
Anaesthetics - measuring pulmonary artery wedge pressures
Haematology - manage the DIC
If baby not yet delivered, CTG with view to imminent delivery
Cardiac arrest or severe maternal compromise - perimortem section indicated to facilitate CPR of the mother

Question 9

How is amniotic fluid embolism diagnosed definitively?

Answer 9

Post mortem - foetal squamous cells along with debris in the pulmonary vasculature