Conclusion
This analysis of women stratified by their baseline characteristics found no group in whom UDCA was effective in reducing bile acid concentrations or itch scores in a clinically important way. In the majority of women, mean bile acid concentrations decreased with time, regardless of treatment, emphasising the importance of evaluating the natural history of the clinical and laboratory investigations, in order to best identify women with sustained abnormal bile acid concentrations. Women and clinicians agree that a 30 mm reduction in itch severity on a 0 to 100 mm scale is clinically meaningful.
Previous work has implicated certain genetic mutations in the pathophysiology of ICP, including genes that directly influence biliary transport.12It is possible that women with a genetic disposition to ICP due to defective biliary transport genes may respond to treatment differently from those without such mutations. Further research is needed both to identify the relevant genetic mutations and to determine whether affected women respond differently to treatment.
Quantification of bile acid concentrations is complex as UDCA itself is a bile acid and is included in standard laboratory measures of total bile acid concentration.13There may be value in further research quantifying changes in harmful bile acid concentrations (such as cholic acid and chenodeoxycholic acid). Further work is needed to understand the pathophysiology behind pruritus in ICP, and develop an effective treatment for itching, in addition to targeting adverse perinatal outcomes associated with ICP.
Routine use of UDCA to reduce bile acid concentrations or itch scores should be reconsidered, and there is no justification for targeting women with high bile acid concentrations or high itch scores at presentation.