1. Department of Obstetrics and Gynaecology Croydon University Hospital London UK
2. Department of Radiology Croydon University Hospital London UK
3. Department of Radiology University Hospitals of North Midlands NHS Trust Stoke‐on‐Trent UK
4. Department of Obstetrics and Gynaecology Jeroen Bosch Ziekenhuis Den Bosch The Netherlands
5. Department of Obstetrics and Gynaecology Epsom & St Helier University Hospitals London UK
6. Department of Obstetrics and Gynaecology St George's University of London London UK
7. Radboud Institute for Health Sciences, Section of Biostatistics Radboud University Medical Center Nijmegen The Netherlands