Pregnancy is a time of great maternal physiological and metabolic changes. This affects the biochemical and haematological parameters used in the assessment of liver disease, and it is important to appreciate the different reference ranges in pregnancy to facilitate recognition of liver disorders in pregnancy. Due to the increased physiological and metabolic stress of pregnancy, liver disorders that have previously been subclinical may become symptomatic-for example, primary biliary cirrhosis. Gallstone disease is a common problem in women of childbearing age, and pregnancy promotes their formation. The viral hepatidides constitute a huge disease burden worldwide and the pregnant state confers particular concerns for the mother and her baby. In particular, hepatitis E has a predilection for the pregnant population and confers a particularly poor prognosis. In addition certain pregnancy specific disorders-for example, haemolysis, elevated liver enzymes, low platelets syndrome, acute fatty liver of pregnancy, and obstetric cholestasis-affect primarily the liver. It is important to know how to diagnose and manage these conditions and distinguish them from non-pregnancy specific conditions as this will change the timing and management of affected women and their babies, some of whom can be seriously ill. We propose an approach to the investigation and management of the pregnant patient with abnormal liver function tests.