Although peak serum total bile acid (TBA) levels guide management of intrahepatic cholestasis of pregnancy (ICP), whether ICP progresses in severity and when or how to assess bile acid levels serially remains unclear. We conducted a secondary analysis of a single-institution retrospective cohort study to assess bile acid trends across pregnancy among individuals diagnosed with ICP and to evaluate whether there was progression to higher ICP severity. We defined ICP severity as mild (peak TBA less than 40 micromol/L), moderate (peak TBA between 40 and 100 micromol/L), or severe (peak TBA 100 micromol/L or greater). Among the 1,188 patients with ICP in our cohort, 354 (29.8%) had repeat bile acid level measurements. Of those patients, 88 (24.9%) progressed to higher ICP severity that may have resulted in changes to delivery timing. Further studies are needed to determine whether serial assessment of bile acid levels with potential reclassification of ICP severity improves outcomes.