|                                  
                 Type                              |                               
                                             
                 Causes                              |                               
                                             
                 Investigations                              |   
                    
                                      
            |                                  
                 Early Onset:                                          
                           (                                          
                    <24 hours)                                                         
                        PATHOLOGICAL                                                                                 
                        All should have:                                                                                  
                                                                                
                                                              |                               
                                             
                 Sepsis              |                               
                                             
                 Please refer to                                           
                    Recognition    of the seriously unwell neonate and young infant                              |   
                    
                                      
            |                                  
                 Haemolysis:                                          
                                                         
                    - Isoimmunisation –    ABO or Rhesus D alloantibodies 
                                          
                    - RBC enzyme    defects – G6PD, hereditary spherocytosis, alpha thalassemia
                                          
                    - Haemorrhage – cerebral, intra-abdominal 
                                          
                    - Blood    extravasation – (bruising/birth trauma)
                               |                               
                                             
                 FBE, film and    reticulocytes                                          
                           Neonatal blood group                                          
                           Direct antiglobulin    test (Coombs)                                          
                           (G6PD screen)                                          
                               |   
                    
                                      
            |                                  
                 Peak Onset                                          
                           (24 hours – 14 days)                                         
                No further    investigations needed unless red flags                                          
                               |                               
                                             
                 Physiological jaundice               |                               
                                             
                 No further    investigations required unless red flags               |   
                    
                                      
            |                                  
                 Dehydration/insufficient    feeding              |                               
                                             
                 Serum sodium, BGL                                          
                           No further    investigations required              |   
                    
                                      
            |                                  
                 Sepsis              |                               
                                             
                 Please refer to                                           
                    Recognition    of the seriously unwell neonate and young infant                              |   
                    
                                      
            |                                  
                 Haemolysis              |                               
                                             
                 FBE, film and    reticulocytes                                          
                           Neonatal blood group                                          
                           Direct antiglobulin    test (Coombs)                                          
                           (G6PD screen)               |   
                    
                                      
            |                                  
                 Breastmilk jaundice              |                               
                                             
                 Diagnosis of exclusion    after considering above causes               |   
                    
                                      
            |                                  
                 Bruising, birth trauma              |                               
                                             
                 No further    investigations required               |   
                    
                                      
            |                                  
                 Prolonged/ conjugated                                          
                           (>2 weeks)                                         
                All should have:                                                          
                                                         
                    - SBR (unconjugated/ conjugated),                     
                                          
                    - FBE, film and reticulocytes,                     
                                          
                    - TFTs                     
                                          
                    - group and DAT                     
                                          
                    - LFTs if conjugated bilirubin >10%                    
                               |                               
                                             
                 Sepsis              |                               
                                             
                 Please refer to                                           
                    Recognition    of the seriously unwell neonate and young infant                              |   
                    
                                      
            |                                  
                 Haemolysis               |                               
                                             
                 FBE, film and reticulocytes                                          
                           Neonatal blood group                                          
                           Direct antiglobulin    test (Coombs)                                          
                           (G6PD screen)               |   
                    
                                      
            |                                  
                 Dehydration/    insufficient feeding              |                               
                                             
                 Serum sodium, BGL                                          
                           No further    investigations required              |   
                    
                                      
            |                                  
                 Breastmilk jaundice              |                               
                                             
                 Diagnosis of exclusion    after considering above causes               |   
                    
                                      
            |                                  
                 Hypothyroidism              |                               
                                             
                 TFTs (to exclude    central hypothyroidism)              |   
                    
                                      
            |                                  
                 Conjugated                                           
                           (At any age point)                                         
                If conjugated fraction    >10% of total bilirubin                                         
                                                                          
                Refer to a specialty unit                              |                               
                                             
                 Neonatal hepatitis              |                               
                                             
                 LFTs, maternal    infectious serology, metabolic screening              |   
                    
                                      
            |                                  
                 Extrahepatic    obstruction:                                           
                           Biliary    atresia, choledochal cyst,    bile plug              |                               
                                             
                 LFTs, coags, abdominal    US                                           
                           Note: a normal ultrasound does not exclude    biliary atresia                              |   
                    
                                      
            |                                  
                 Metabolic                |                               
                                             
                 Alpha-1 anti-trypsin    levels, urinary reducing substances              |   
                    
                                      
            |                                  
                 Drugs/Parenteral    nutrition               |                               
                                             
                 Investigations as    appropriate after history and exam               |