Global incidence of intrahepatic cholestasis of pregnancy: A protocol for systematic review and meta-analysis.

BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP) typically develops in the late second and third trimesters and resolves rapidly after delivery. Although not associated with serious maternal sequelae, ICP can be highly bothersome. On the other hand, the major complications of ICP are fetal and neonatal, which can be fatal. The current knowledge lacks an estimation regarding the global prevalence of ICP.

METHODS: PubMed, Scopus, and Web of Science will be searched systematically. Records will be screened for eligibility by two independent reviewers. Observational studies that reported the incidence of ICP will be eligible. Joanna Bridge Institute checklist for appraisal of prevalence studies will be used for quality assessment. Freeman-Tukey double arcsine transformed effect sizes will be pooled under random-effect models. The residual between study heterogeneity will be quantified using I 2 statistic. Further investigations will be done using subgroup and meta-regression analyses.

DISCUSSION: Estimating the global and regional prevalence of ICP and evaluating the effects of moderating factors will provide valuable insights into the knowledge. Further investigations on the moderating factors will help researchers to hypothesize the associations and extend the current understanding of the disease. The planned study will be the first systematic review and meta-analysis that estimates the global prevalence of ICP. The reviewers will try rigorous mythology to ensure high-quality evidence. However, substantial heterogeneity is expected as prevalence studies utilize different mythologies, settings, and definitions. Moreover, this study relies on utilizing previously published studies, which may impede the overall data quality and comprehensiveness.