Bile acids

Chemical Pathology

Notes

• Bile acid analysis is available for the investigation of possible obstetric cholestasis.
  
• Bile acids are elevated in many hepatic diseases but add no further information to routine liver function tests (LFT's) and should not therefore be requested. One exception to this is in the investigation of an isolated but persistently raised bilirubin level where Gilbert's syndrome is suspected. A normal bile acid level can assist the diagnosis.
  
• Obstetric cholestasis classically manifests itself in the second or third trimester of pregnancy with generalised pruritis, most pronounced in palms of hands and soles of feet. Jaundice is relatively uncommon, complicating only the most severe and prolonged episodes. Routine LFT's show raised transaminases in 60% of patients and raised bilirubin in only 25%. Serum bile acids are raised in the vast majority of patients although a normal bile acid level does not exclude cholestasis.
  
• Other causes of pruritis must be excluded.
  

Sample requirements

For adults, blood taken into a 5mL gold top tube (or rust top for the Acute Unit)

Storage/transport

Do not store. Send to the laboratory the same day.

Required information

Relevant clinical details including stage of pregnancy.

Turnaround times

The assays are run throughout the normal working day.

The in-lab turnaround time is less than 24 hours.

Reference ranges

Serum bile acids: Less than 10 µmol/L

Further information

Royal College of Obstetricians and Gynaecologists: Obstetric Cholestasis Guidelines

Page last updated 07/05/2015