Neonatal jaundice

Question 1

What is neonatal jaundice?

Answer 1

Serum bilirubin > 80 umol/L

Over 50% of newborns are jaundiced.

Question 2

What is the mechanism of physiological neonatal jaundice?

Answer 2

1. Neonatal RBC lifespan is 70 days
2. High RBC breakdown after birth
3. Hepatic bilirubin metabolism is less efficient in first few days of life.

Question 3

What is kernicterus?

Answer 3

Neonatal encephalopathy from deposit of unconjugated bilirubin in basal ganglia and brainstem nuclei
Non albumin bound bilirubin is fat soluble and crosses the BBB
Acute clinical - lethargy and poor feeding
Severe - irritability, opisthotonus, seizures, coma, death
Long term - choreoathetoid cerebral palsy, sensorineural deafness and learning difficulties.

Question 4

What factors determine management?

Answer 4

Gestational age (premies are more vulnerable)
Age at jaundice
Bilirubin level and rate of rise (SBR chart)
Clinical severity (crania-caudal yellowish appearance)
Avoid bilirubin displacers (diazepam/sulphonamides)

Question 5

What are the causes of neonatal jaundice?

Answer 5

At birth = 
hemolysis (unconjugated)
-ABO incompatibility (no HSM)
-Rhesus disease (has HSM, severe jaundice)
-G6PD (mostly males)
-HS (family history)
congenital infection (conjugated)

2 days to 2 weeks = 
Dehydration (delayed breastfeeding)
Infections (UTI etc)
Hemolysis
Breast milk jaundice (increased EHC)
Bruising
Polycythemia
Crigler-Najjar syndrome (no UDP-GlucTrans)

> 2 weeks (persistent) =
-Conjugated
BILIARY ATRESIA
Neonatal hepatitis syndrome

-Unconjugated
Breast milk jaundice
Infection
Congenital hypothyroidism
G6PD hemolysis
Pyloric stenosis

Question 6

How is neonatal jaundice managed?

Answer 6

1. Correct breastfeeding
2. Phototherapy (risk of hypothermia)
3. Exchange transfusion (replace 2x 80 mL/kg)