Neonatal jaundice incl. Breast milk jaundice Flashcards
Define neonatal jaundice.
Excess amount of bilirubin in the neonatal circulation causing a yellow discolouration of the skin and sclera.
What are the main categories of causes of neonatal jaundice?
- Physiological unconjugated hyperbilirubinaemia
- Breast milk jaundice
- Unconjugated haemolytic hyperbilirubinaemia
- Unconjugated non-haemolytic hyperbilirubinaemia
- Conjugated hyperbilirubinaemia
Explain the aetiology of physiological unconjugated hyperbilirubinaemia.
Secondary to:
Instability of fetal haemoglobin: Neonates have increased RBC volume but decrease RBC survival.
Defective bilirubin metabolism: Immature hepatic function results in defective hepatic uptake and conjugation of bilirubin.
Defective bilirubin excretion: Neonates have absent gut flora.
Explain the aetiology of breast milk jaundice.
Physiological prolonged unconjugated hyperbilirubinaemia; peaks in the 2nd week and resolves very slowly (<3/12).
Secondary to a factor in breast milk that inhibits uridine diphosphoglucuronic acid (UDPGA).
Explain the aetiology of unconjugated haemolytic hyperbillirubinaemia.
Immune mediated: Haemolytic disease of the newborn which may be secondary to ABO or rhesus incompatibility.
Hereditary: Spherocytosis, elliptocytosis, G6PD deficiency.
Acquired: Congenital infection, bacterial sepsis.
Explain the aetiology of unconjugated non-haemolytic hyperbilirubinaemia.
Increased haemoglobin load; haemorrhage, polycyhtaemia
Glactosaemia, hypothyroidism
Explain the aetiology of conjugated hyperbilirubinaemia.
Bile duct obstruction: Biliary atresia, choledochal cyst
Neonatal hepatitis: TPN- related heptatitis, congenital infection, alpha1- antitrypsin deficiency, cystic fibrosis
What are risk factors for neonatal jaundice?
Previous affected sibling
Prematurity
Breastfeeding
Summarise the epidemiology of neonatal jaundice.
50% of all neonates to various degree.
33% of breastfed neonates >2/52.
What are the presenting symptoms of neonatal jaundice?
General presentation: May be asymptomatic in physiological jaundice or unwell (vomiting, lethargy, poor feeding, behavioural changes, tachypnoea, instability of temperature, pale stools and dark urine).
Age of onset: Important in determining likely pathological cause; < 24 hours (pathological), >24 hours (probably physiological but beware sepsis and galactosaemia), >2/52 (investigate).
What are the signs of neonatal jaundice?
Clinically jaundice at bilirubin of 80-120micro mol/L. Correlation between the level to which the jaundice extends and the serum bilirubin level. Sclera is the best place to detect jaundice as there are variation in skin colour.
Examine also for pallor, presence of hepatosplenomegaly, signs of sepsis and petechiae.
What are appropriate investigations for neonatal jaundice?
Early jaundice (<24 hours): FBC, blood film, maternal and infant ABO and rhesus typing, direct coombs (antiglobulin test), infection screen (blood culture, TORCH screen).
Jaundice at >24 hours: If normal history and examination, monitor only.
Persistent jaundice (> 2 weeks): Total serum bilirubin and conjugated fraction should be obtained. TFTs, LFTs, urine for reducing agents in G6PD, DAT.
Conjugated hyperbilirubinaemia: Requires urgent investigation; USS billary tree +/- liver biopsy isotope scanning HIDA/DISIDA and referral to a paediatric liver centre.
What is the management for neonatal jaundice?
General: Treat the cause if present.
Treatment of jaundice: Place the neonate under a series of 450nm wavelength lights on a radiant warmer bed. Converts the stereoisomer, making it soluble and allowing renal excretion. Eye protection masks during therapy.
Exchange transfusion: If intensive phototherapy fails to lower bilirubin level, or in conjunction with phototherapy with extremely elevated bilirubin levels in all age groups. All neonates with bilirubin levels over the exchange transfusion level should have hearing screening. Can be performed via an umbilical vein catheter.
What are complications associated with neonatal jaundice?
Bilirubin neurotoxic effects: Seizures, athetoid cerebral palsy, sensorineural deafness and learning difficulties.
What is the prognosis of neonatal jaundice?
Good with physiological jaundice as usual spontaneous resolvement.
