Intrahepatic cholestasis of pregnancy as an indicator of liver and biliary diseases: a population-based study.

Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder, thought to be specific for pregnancy and to spontaneously resolve after delivery. Increased rates of gallstone formation and hepatitis C have previously been associated with ICP. However, there are no longitudinal studies to determine its significance as an indicator of subsequent liver or biliary diseases. In this retrospective cohort study with cases and controls we assessed the risk of liver and biliary diseases in 21,008 women, 10,504 with a history of ICP during the years 1972-2000 (cases) and 10,504 with a normal pregnancy (controls). Cases and controls were matched for age, time of delivery, and place of delivery. The diagnoses of liver and biliary disease were traced from the Finnish Hospital Discharge Register with an almost 100% coverage. Several liver and biliary diseases were found to have a significantly higher incidence in patients with ICP than in controls. The rate ratio for hepatitis C was 3.5 (CI 1.6-7.6; P < .001), for nonalcoholic liver cirrhosis 8.2 (CI 1.9-35.5; P < .05), for gallstones and cholecystitis 3.7 (CI 3.2-4.2; P < .001) and for nonalcoholic pancreatitis 3.2 (CI 1.7-5.7; P < .001). In conclusion, there is an association of ICP with several liver and biliary diseases. Some patients with ICP are at risk of the subsequent development of cirrhosis and other severe chronic diseases. Contrary to what has been previously thought, follow-up may need to be considered for these patients.