1. Department of Reproductive Medicine and Gynecology, University Medical Center Utrecht, Utrecht University, Room Number: F05.126, Utrecht, The Netherlands
2. Department of Gynaecology, Amsterdam University Medical Centre, location AMC, Amsterdam, The Netherlands
3. Department of Obstetrics and Gynaecology, Imelda Hospital, Bonheiden, Belgium Centre for Evidence-Based Medicine, Cochrane Belgium, Leuven, Belgium