Neonatal Jaundice

Question 1

Causes of neonatal jaundice <24hrs (7)

Answer 1

haemolysis:

• ABO incompatibility
• hereditary spherocytosis/G6PD
• increased haemolysis due to haematoma
• haemolytic disease of the newborn
• maternal drugs e.g. sulphonamides, nitrofurantoin

Gilbert’s (unconjugated bilirubin)

infection-from maternal genital tract/amniotic fluid. do TORCH screen.

Question 2

Causes of neonatal jaundice between 2-14d (2)

Answer 2

physiological jaundice

breastfeeding jaundice

Question 3

Mechanism of physiological jaundice (5)

Answer 3

in utero, there is downregulation of enzymes which conjugate bilirubin as unconjugated bilirubin needs to cross the placenta or it will accumulate in the foetus

Foetal RBCs have a shorter lifespan

Foetal Hb levels are around 18-22>increased haemolysis as this is not needed ex-utero (all neonates are polcythaemic, esp. IUGR)

the immature liver is unable to cope with all this excess bilirubin

therefore bilirubin is UNCONJUGATED

(can be exacerbated by polycythaemia, extravasated blood, delayed passage of meconium, hypocalorific feeding, breastfeeding, prematurity, dehydration, swallowed blood)

Question 4

Features and advice for breastfeeding jaundice (3)

Answer 4

increased enterohepatic bilirubin

due to lower calorie intake and delayed passage of meconium

continue breastfeeding

Question 5

Ix for prolonged neonatal jaundice (>14d or 21d in preterm) (2)

Answer 5

all require Ix for conjugated bilirubinaemia

any prolonged jaundice>immediate split bilirubin

Question 6

Causes of uconjugated prolonged jaundice (8)

Answer 6

breastfeeding: benign

enclosed bleeding e.g. cephalohaematoma

haemolysis: spherocytosis, G6PD

haemolytic disease OTN: ABO/Rh

hypothyroidism

sepsis

prematurity

hepatic enzyme disorders: Gilbert’s, Crigler-Najjar

Question 7

Causes of conjugated, prolonged jaundice (9)

Answer 7

Biliary atresia

cholestasis

choledochal cyst

TORCH

sepsis

TPN

CF

galactosaemia

A1-anti-trypsin deficiency

(if conjugated, refer immediately to liver team)

Question 8

Consequences of untreated neonatal jaundice (2)

Answer 8

hepatic failure due to accumulation of bilirubin

kernicterus:

• concentration of bilirubin so high it crosses BBB>basal ganglia>athetoid/dyskinetic cerebral palsy
• presents w. shrill cry, opisthotonus, poor feeding, fits, coma, death
• Long term: athetoid movements, lowered IQ, deafness

Question 9

Other presenting features of jaundice (5)

Answer 9

yellow vernix

hepatosplenomegaly

CCF: oedema, ascites

bleeding

CNS signs

Question 10

Ix for neonatal jaundice (7)

Answer 10

serum bilirubin

FBC, LFTs, TFTs

TORCH screen

blood film-reticulocytes?

Coomb’s (direct)

Blood group

Urine dip: bilirubin, sepsis source

Question 11

Mx of neonatal jaundice (5)

Answer 11

plot on bilirubin chart

if under 1st line and all tests -ve, then supportive Mx only

if over 1st line, phototherapy:
-breaks down unconjugated bilirubin into soluble isomers

if over 2nd line, exchange transfusion:

• replace baby’s blood w. warm blood 2x via umbilical venous catheter paired w. an arterial line
• complications: bradycardia, apnoea, low platelets/glucose/sats/Na/Hb

IVIg can be used for ABO/Rh incompatibilty