1.5 Disorders of transition

Question 1

What causes failure to transition?

Answer 1

• Foetal compromise before labour, during labour or after birth.
• -> Prior to birth/during labour: Any event that compromises placental function or blood flow through umbilical cord
• -> Post birth: issues with newborn’s airway and/or lungs

Question 2

Factors before birth/during labour which cause failure to transition?

Answer 2

• Antepartum haemorrhage
• Placental abruption
• Cord prolapse/compression
• Cord around neck
• Maternal pre-eclampsia

Question 3

Factors at time of birth which cause failure to transition?

Answer 3

Any event impacting lung aeration

• Insufficient breathing to force liquid from alveoli
• If materials block airway (e.g. meconium/blood)
• Underlying structural malformation of infant airway
• Development of significant air leak either spontaneously or due to being over-ventilated
• Birth injuries

Question 4

What occurs if effective ventilation is not established by the newborn?

Answer 4

• Bradycardia: due to decreased myocardial perfusion
• Depressed respiratory drive: due to decreased brain stem perfusion
• Hypotension: due to hypoxia, bradycardia and decreased myocardial contractility
• Cyanosis (beyond 10 mins of birth): due to hypoxaemia
• Poor muscle tone: due to insufficient perfusion of brain, muscles and other organs