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Bile acids

Blood Sciences Test



Special Instructions

Only indicated during pregnancy (usually third trimester). Fasting is not required for this test.



Reference Range

0- 18.9 umol/L

Test Usage

Total bile acids (TBA) are an aid to the diagnosis of intrahepatic cholestasis of pregnancy (ICP; obstetric cholestasis) in woman with itching, in the absence of a rash during pregnancy (usually but not solely the third trimester). TBA are a sensitive but not specific marker of ICP and may be abnormal before ALT elevation.

From: Royal College of Obstetricians and Gynaecologists (RCOG) guideline Intrahepatic cholestasis of pregnancy (revised by RCOG January 2022):

The diagnosis of ICP should be considered in pregnant women who have itching in skin of normal appearance and raised peak random total bile acid concentration of 19 micromol/L or more. The diagnosis is more likely if it is confirmed that itching and raised bile acids resolve after birth.

If a diagnosis of ICP is suspected, carry out a structured history and examination, so that other causes of itching and liver dysfunction can be excluded.

Offer repeat liver function tests and bile acid measurement (depending on gestation and clinical context) in women with normal blood results whose itch persists, and no other cause is apparent.

View the RCOG Guidelines

There is rarely a need for repeat testing once ICP has been diagnosed, as treatment with ursodeoxycholic acid cross-reacts with the assay.

Turnaround Time

1 day


Can be added on to an existing request up to 4 days following sample receipt.


This test is UKAS accredited to ISO 15189:2012 (UKAS 8210)

Specimen Labelling Procedure
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