What are the key diagnostic criteria for intrahepatic cholestasis of pregnancy (ICP) in a patient presenting with pruritus?

Key diagnostic criteria for intrahepatic cholestasis of pregnancy (ICP) in a patient presenting with pruritus include:

• Presence of pruritus, typically without a primary rash, often worse on the palms and soles, occurring in the second or third trimester of pregnancy.
• Elevated maternal serum bile acid concentrations, which are the most specific biochemical marker for ICP diagnosis.
• Abnormal liver function tests (LFTs), including raised transaminases (alanine aminotransferase and aspartate aminotransferase) and gamma-glutamyl transferase, supporting the diagnosis.
• Exclusion of other causes of liver dysfunction and pruritus in pregnancy, such as pre-eclampsia, fatty liver of pregnancy, viral hepatitis (A, B, C), Epstein-Barr virus, cytomegalovirus, and autoimmune liver diseases like primary biliary cirrhosis.
• Referral for same-day assessment at a maternity unit for serum bile acid measurement and LFTs is recommended when clinical features suggest ICP.

In cases where pruritus is present but bile acids and LFTs are normal, weekly monitoring is advised until resolution or further specialist advice if symptoms worsen.

Fetal wellbeing assessment is part of the diagnostic workup but cardiotocography does not predict future fetal outcomes.

These criteria are based on the Royal College of Obstetricians and Gynaecologists guideline and expert consensus, which emphasize the importance of biochemical confirmation with serum bile acids and LFTs alongside clinical presentation NICE CKS.

Recent literature corroborates the central role of serum bile acids in diagnosis and highlights the need for careful exclusion of other hepatic conditions Walker et al. 2020Abdul Waheed et al. 2024.