Intrahepatic cholestasis of pregnancy (ICP) is a rare pregnancy-related liver disease characterized by pruritus, abnormal liver function tests, and an increased risk of fetal complications. An increase in the levels of bile acids is considered to be the diagnostic hallmark of the disease. Ursodeoxycholic acid (UDCA) is currently the most effective therapy. Tribe et al. (this issue) hypothesized that measuring the longitudinal profiles of individual bile acids would provide further insight into the mechanisms of disease. They used a novel chromatography method, which allowed the simultaneous measurement of 15 serum bile acids between 16 weeks of pregnancy and 4 weeks post-partum. ICP was associated with a predominant rise in cholic acid conjugated with taurine and glycine from 24 weeks of pregnancy. UDCA treatment significantly reduced serum taurocholic and taurodeoxycholic acid concentrations. Finally, bile acid profiles were similar in normal pregnancy and pregnancy associated with pruritus gravidarum. The study by Tribe et al. (this issue) presents a significant contribution to the solution of this enigmatic disease by expanding our knowledge on the pathophysiology of ICP and proposing a convenient method for diagnosis and monitoring of this disorder.