Objective To determine whether exclusion of other causes of liver dysfunction is necessary in the diagnosis of obstetric cholestasis(OC), previous studies have not addressed this question.

Methods Retrospective analysis of investigations undertaken to exclude alternative pathologies in women presenting with symptoms of OC and abnormal liver function tests(LFTs) and/or raised bile acids(BA).

Population 127 women attending hospital for assessment of possible OC with abnormal LFTs and/or raised BA. Women with additional symptoms not consistent with OC and pre-existing liver disease were excluded.

Results 130 women were assessed, 102 were screened for acute hepatitis A,B&C; Cytomegalovirus(CMV) and Epstein-Barr Virus(EBV), 103 underwent an autoimmune screen and 87 underwent a liver ultrasound scan(USS). Of those who underwent an USS 76% had no abnormality, 21% had uncomplicated gallstones, 2.2% had an uncomplicated gallbladder polyp or haemangioma and 1.1% had appearances suggestive of significant chronic liver disease. Of those who had a viral hepatitis screen 6.9% had no evidence of past or current infection, 82% had evidence of past EBV infection, 5.9% had evidence of recent EBV infection, 4.9% had evidence of past CMV infection, 1% had evidence of primary CMV infection. Of those who had an autoimmune screen 97% had negative or insignificant findings, 1.9% had gastric parietal cell antibodies and 1% had significant smooth muscle antibodies.

Conclusion In the vast majority of cases a clinical diagnosis of OC will be correct. However in a small minority, significant disease may be missed if alternative pathologies are not excluded in the diagnosis of OC.