1. Department of Obstetrics and Gynecology; University Medical Center Groningen, University of Groningen; Groningen The Netherlands
2. Department of Obstetrics and Gynaecology; St George's, University of London; London UK
3. Department of Gynecology and Obstetrics; Johns Hopkins University School of Medicine; Baltimore MD USA
4. College of Medicine, Biological Sciences & Psychology; University of Leicester; Leicester UK
5. Department of Obstetrics and Gynecology; University of Utah Health Sciences Center; Salt Lake City UT USA
6. Department of Health Sciences, Community and Occupational Medicine; University Medical Center Groningen, University of Groningen; Groningen The Netherlands
7. Department of Obstetrics and Gynecology; Academic Medical Center, University of Amsterdam; Amsterdam The Netherlands