Biliary Atresia

Last updated: April 1, 2026

Biliary atresia is a progressive fibro-inflammatory obliteration of the lumen of the biliary tree. It causes conjugated hyperbilirubinaemia, since there are defects in the biliary tract, resulting in cholestasis. The conjugated bilirubin is reabsorbed into the bloodstream, causing a direct hyperbilirubinaemia.

It has a slight female preponderance.

  • Signs and symptoms
    • A neonate who was normal on delivery and discharge
    • Develops jaundice at 2-3 weeks of life
    • Dark urine
    • Acholic (clay-colored) stools
    • Failure to thrive within a few months
    • Signs and symptoms of portal hypertension (ascites, splenomegaly, etc.) within a few months
  • Investigations
    • LFTs
      • Elevated ALP and GGT
    • Abdominal ultrasound: This is the best initial test. It is done to rule out a choledochal cyst and extrinsic compression
      • “Triangular cord sign” along the porta hepatis
    • HIDA scan:
      • Normal uptake
      • Decreased excretion
    • Percutaneous liver biopsy
    • Intraoperative cholangiogram: This is the most accurate diagnostic test
  • Treatment
    • Kasai procedure (hepatoportoenterostomy)
      • It should be performed early, within 8 weeks of age
    • Transplantation
    • Post-operative nutritional supplementation
      • A formula with medium-chain triglycerides is recommended
    • Monitor fat-soluble vitamins
Reference Intervals
Biochemistry
ACTHP: <80 ng/L
ALTP: 5–35 U/L
AlbuminP: 35–50 g/L
AldosteroneP: 100–500 pmol/L
Alk. phosphataseP: 30–130 U/L
α-AmylaseP: 0–180 IU/dL
α-FetoproteinS: <10 kU/L
Angiotensin IIP: 5–35 pmol/L
ADHP: 0.9–4.6 pmol/L
ASTP: 5–35 U/L
BicarbonateP: 24–30 mmol/L
BilirubinP: 3–17 μmol/L
BNPP: <50 ng/L
CRPP: <10 mg/L
CalcitoninP: <0.1 mcg/L
Calcium (ionized)P: 1.0–1.25 mmol/L
Calcium (total)P: 2.12–2.60 mmol/L
ChlorideP: 95–105 mmol/L
CholesterolP: <5.0 mmol/L
VLDLP: 0.128–0.645 mmol/L
LDLP: <2.0 mmol/L
HDLP: 0.9–1.93 mmol/L
Cortisol AMP: 450–700 nmol/L
Cortisol MidnightP: 80–280 nmol/L
CK ♂P: 25–195 U/L
CK ♀P: 25–170 U/L
CreatinineP: 70–100 μmol/L
FerritinP: 12–200 mcg/L
FolateS: 2.1 mcg/L
FSHP: 2–8 U/L ♂; >25 menopause
GGT ♂P: 11–51 U/L
GGT ♀P: 7–33 U/L
Glucose (fasting)P: 3.5–5.5 mmol/L
Growth hormoneP: <20 mu/L
HbA1C (DCCT)B: 4–6%
HbA1C (IFCC)B: 20–42 mmol/mol
Iron ♂S: 14–31 μmol/L
Iron ♀S: 11–30 μmol/L
Lactate (venous)P: 0.6–2.4 mmol/L
Lactate (arterial)P: 0.6–1.8 mmol/L
LDHP: 70–250 U/L
LHP: 3–16 U/L
MagnesiumP: 0.75–1.05 mmol/L
OsmolalityP: 278–305 mosmol/kg
PTHP: 0.8–8.5 pmol/L
PotassiumP: 3.5–5.3 mmol/L
Prolactin ♂P: <450 U/L
Prolactin ♀P: <600 U/L
PSAP: 0–4 mcg/mL
Protein (total)P: 60–80 g/L
Red cell folateB: 0.36–1.44 μmol/L
Renin (erect)P: 2.8–4.5 pmol/mL/h
Renin (recumbent)P: 1.1–2.7 pmol/mL/h
SodiumP: 135–145 mmol/L
TBGP: 7–17 mg/L
TSHP: 0.5–4.2 mU/L
T4P: 70–140 nmol/L
Free T4P: 9–22 pmol/L
TIBCS: 54–75 μmol/L
TriglyceridesP: 0.50–2.3 mmol/L
T3P: 1.2–3.0 nmol/L
Troponin TP: <0.1 mcg/L
Urate ♂P: 210–480 μmol/L
Urate ♀P: 150–390 μmol/L
UreaP: 2.5–6.7 mmol/L
Vitamin B12S: 0.13–0.68 nmol/L
Vitamin DS: 50 nmol/L
Arterial Blood Gases
pH7.35–7.45
PaCO₂4.7–6.0 kPa
PaO₂>10.6 kPa
Base excess±2 mmol/L
Urine
Cortisol (free)<280 nmol/24h
Hydroxyindole acetic acid16–73 μmol/24h
Hydroxymethylmandelic acid16–48 μmol/24h
Metanephrines0.03–0.69 μmol/mmol cr.
Osmolality350–1000 mosmol/kg
17-Oxogenic steroids ♂28–30 μmol/24h
17-Oxogenic steroids ♀21–66 μmol/24h
17-Oxosteroids ♂17–76 μmol/24h
17-Oxosteroids ♀14–59 μmol/24h
Phosphate (inorganic)15–50 mmol/24h
Potassium14–120 mmol/24h
Protein<150 mg/24h
Protein/creatinine ratio<3 mg/mmol
Sodium100–250 mmol/24h
Haematology
WCC4.0–11.0 ×10⁹/L
RBC ♂4.5–6.5 ×10¹²/L
RBC ♀3.9–5.6 ×10¹²/L
Hb ♂130–180 g/L
Hb ♀115–160 g/L
PCV ♂0.4–0.54 L/L
PCV ♀0.37–0.47 L/L
MCV76–96 fL
MCH27–32 pg
MCHC300–360 g/L
RDW11.6–14.6%
Neutrophils2.0–7.5 ×10⁹/L (40–75%)
Lymphocytes1.0–4.5 ×10⁹/L (20–45%)
Eosinophils0.04–0.44 ×10⁹/L (1–6%)
Basophils0–0.10 ×10⁹/L (0–1%)
Monocytes0.2–0.8 ×10⁹/L (2–10%)
Platelets150–400 ×10⁹/L
Reticulocytes0.8–2.0% / 25–100 ×10⁹/L
Prothrombin time10–14 s
APTT35–45 s
Paediatric
Pulse Rate (bpm)
Neonate140–160
Infant <1yr120–140
1–5 years110–130
5–12 years80–120
>12 years70–100
Respiratory Rate (tachypnoea)
0–2 months≥60/min
2–12 months≥50/min
1–5 years≥40/min
>5 years≥30/min
Blood Pressure (mmHg)
Term65/45
1 year75/50
4 years85/60
8 years95/65
10 years100/70
Weight Formulas
3–12 months(a + 9)/2 kg
1–6 years2a + 8 kg
>6 years(7a − 5)/2 kg
Haemoglobin (g/dL)
Term newborn13–20
1 month11–18
2 months10–15
1–2 years10–13
>2 years11–14
MUAC (6 months–5 years)
Obese>17.5 cm
Normal13.5–17.4 cm
At risk12.5–13.4 cm
Moderate malnutrition11.5–12.4 cm
Severe malnutrition<11.5 cm
Developmental Milestones
Social smile1.5 months
Head control4 months
Sits unsupported7 months
Crawls10 months
Stands unsupported10–12 months
Walks12–13 months
Talks18 months
CSF WBC (/mm³)
Term newborn0–25
>2 weeks0–5
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