A core outcome set for studies of intrahepatic cholestasis of pregnancy: results of international e‐Delphi and consensus processes
Author(s)
Capatina, Nadejda
Hague, William
Chambers, Jenny
Williamson, Catherine
Ovadia, Caroline
Type
Journal Article
Abstract
Objective
To define standardised outcomes, the Core Outcome Set (COS) for reporting in studies of Intrahepatic Cholestasis of Pregnancy (ICP).
Design
e-Delphi survey and consensus process.
Setting
International.
Population
155 individuals from Asia, Europe, Oceania, North and South America: 31 patients (20%), 121 clinicians (78%), and 3 researchers (2%).
Methods
Maternal and perinatal outcomes reported in studies of ICP were collated. Stakeholders in ICP research and clinical care scored the importance of each outcome using a 9-point Likert scale over three rounds; short-listed outcomes were ranked during face-to-face consensus meetings. The final COS was agreed by the Study Steering Committee. The study was registered prospectively with Core Outcome Measures in Effectiveness Trials. Ethical approval was granted by the King's College London Research Ethics Committee (KCL MRA-23/24-39574).
Main Outcome Measures
From 54 manuscripts, 97 individual clinical outcomes were attributed to ICP. Twenty three outcomes were shortlisted by the e-Delphi surveys, the ranking of which enabled selection of 10 core outcomes.
Results
Maternal core outcomes comprise: total maternal bile acid (BA) concentration (maximum), gestational age at peak BA concentration, and itch impact on maternal wellbeing. Birth core outcomes comprise: stillbirth, gestational age at birth, and spontaneous preterm birth versus induced preterm birth. Neonatal core outcomes comprise: perinatal death within 7 days of birth, perinatal asphyxia, neonatal unit admission, and mechanical ventilation.
Conclusions
Given the heterogeneity of reported outcomes, we have confirmed the need for a COS in ICP, standardising the minimum reported outcomes to reduce outcome reporting bias and research wastage.
To define standardised outcomes, the Core Outcome Set (COS) for reporting in studies of Intrahepatic Cholestasis of Pregnancy (ICP).
Design
e-Delphi survey and consensus process.
Setting
International.
Population
155 individuals from Asia, Europe, Oceania, North and South America: 31 patients (20%), 121 clinicians (78%), and 3 researchers (2%).
Methods
Maternal and perinatal outcomes reported in studies of ICP were collated. Stakeholders in ICP research and clinical care scored the importance of each outcome using a 9-point Likert scale over three rounds; short-listed outcomes were ranked during face-to-face consensus meetings. The final COS was agreed by the Study Steering Committee. The study was registered prospectively with Core Outcome Measures in Effectiveness Trials. Ethical approval was granted by the King's College London Research Ethics Committee (KCL MRA-23/24-39574).
Main Outcome Measures
From 54 manuscripts, 97 individual clinical outcomes were attributed to ICP. Twenty three outcomes were shortlisted by the e-Delphi surveys, the ranking of which enabled selection of 10 core outcomes.
Results
Maternal core outcomes comprise: total maternal bile acid (BA) concentration (maximum), gestational age at peak BA concentration, and itch impact on maternal wellbeing. Birth core outcomes comprise: stillbirth, gestational age at birth, and spontaneous preterm birth versus induced preterm birth. Neonatal core outcomes comprise: perinatal death within 7 days of birth, perinatal asphyxia, neonatal unit admission, and mechanical ventilation.
Conclusions
Given the heterogeneity of reported outcomes, we have confirmed the need for a COS in ICP, standardising the minimum reported outcomes to reduce outcome reporting bias and research wastage.
Date Issued
2026-04-01
Date Acceptance
2025-12-28
Citation
BJOG: An International Journal of Obstetrics & Gynaecology, 2026, 133 (5), pp.1065-1073
ISSN
1470-0328
Publisher
Wiley
Start Page
1065
End Page
1073
Journal / Book Title
BJOG: An International Journal of Obstetrics & Gynaecology
Volume
133
Issue
5
Copyright Statement
© 2026 The Author(s). BJOG: An International Journal of Obstetrics and Gynaecology published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/41513274
Subjects
Core outcome set
bile acid
intrahepatic cholestasis of pregnancy
stillbirth
Humans
Female
Pregnancy
Cholestasis, Intrahepatic
Pregnancy Complications
Consensus
Delphi Technique
Pregnancy Outcome
Outcome Assessment, Health Care
Publication Status
Published
Coverage Spatial
England
Date Publish Online
2026-01-09