• Used in most UK maternity units following results and recommendation of pulse-oximetry study to detect critical congenital heart defects for babies born ≥34 weeks’ gestation in addition to, but usually before clinical examination
  
  • serious non-cardiac conditions may also be identified

Flowchart 1: Pulse-oximetry screening test

Initial assessment of test-positive baby

Assess cardiac and respiratory systems

• Is baby symptomatic?
  
  • quiet, less responsive
  • temperature instability
  • tachypnoea with respiratory rate ≥60 min
  • respiratory distress
  • grunting respirations
  • nasal flaring
  • chest wall recession
  • apnoea 

Examination

• Abnormal breath sounds
• Heart murmur
• Weak or absent femoral pulse
• Response to oxygen therapy

History

• Previous cardiac defect or congenital infection?
• Suspicion of congenital abnormality on antenatal scan?
• Maternal illness during pregnancy, including diabetes?
• Drug ingestion during pregnancy (anticonvulsants)?
• PROM
• Positive maternal culture
• Maternal fever or raised inflammatory markers
• Foul-smelling liquor
• Mode of delivery
• Need for resuscitation (Apgar score)

Any test-positive baby

• See Flowchart 2
• Seen by appropriately trained paediatric staff
• Seek advice from paediatric middle grade or above

Admission

• Admit to NNU for assessment if:
  
  • abnormal examination findings or 
  • pulse-oximetry screening positive on 3 occasions (see Flowchart 2)

Investigations

• If respiratory/infective condition suspected from history/examination and
  saturations improve with oxygen
  • FBC/CRP/blood culture/chest X-ray as appropriate

Echocardiogram

• Indicated if any of the following:
  
  • CVS examination abnormal
  • no respiratory signs
  • no response to oxygen
  • low saturations persist
  • no satisfactory explanation
• If echo unavailable, contact consultant regarding prostaglandin E₂ infusion/paediatric cardiology input (see Congenital heart disease and Prostaglandin infusion guidelines)

Flowchart 2: Positive pulse-oximetry screen (abnormal test)