Intrahepatic cholestasis of pregnancy and cancer, immune-mediated and cardiovascular diseases: A population-based cohort study

Abstract

Intrahepatic cholestasis of pregnancy (ICP) is the most common liver disease in pregnancy. It is associated with hepatobiliary diseases that might predispose to cancer and also with gestational diabetes and preeclampsia. In this study, we examined associations between ICP and cancer, and immune-mediated and cardiovascular diseases. By linking the Swedish Medical Birth Register and the Swedish Patient Register, we identified 11,388 women with ICP and 113,893 matched women without ICP who gave birth between 1973 and 2009. Diagnoses of cancer and immune-mediated and cardiovascular diseases both before and after delivery were obtained from the Patient Register. The main outcome measures were hazard ratios (HRs), calculated through Cox regression, for the indicated diseases after delivery. ICP was not associated with later overall cancer (HR 1.07, 95% confidence interval [CI] 0.94-1.21), but it was associated with later liver and biliary tree cancer (HR 3.61, 95% CI 1.68-7.77, and 2.62, 95% CI 1.26-5.46, respectively). ICP was also associated with later immune-mediated diseases (HR 1.28, 95% CI 1.19-1.38), and specifically diabetes mellitus (HR 1.47, 95% CI 1.26-1.72), thyroid disease (HR 1.30, 95% CI 1.14-1.47), psoriasis (HR 1.27, 95% CI 1.07-1.51), inflammatory polyarthropathies (HR 1.32, 95% CI 1.11-1.58) and Crohn's disease (HR 1.55, 95% CI 1.14-2.10), but not ulcerative colitis (HR 1.21, 95% CI 0.93-1.58). Women with ICP also had a small increased risk of later cardiovascular disease (HR 1.12, 95% CI 1.06-1.19). Women with ICP have increased risk of later hepatobiliary cancer and immune-mediated and cardiovascular diseases.