1 Department of Obstetrics and Gynaecology, Amsterdam Reproduction & Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
2 Department of Obstetrics and Gynaecology, Spaarne Gasthuis, Hoofddorp, The Netherlands.
3 Department of Obstetrics and Gynaecology, Reinier de Graaf Hospital, Delft, The Netherlands.
4 Department of General Practice/Women's Studies Medicine, University Medical Centre Radboud, Nijmegen, The Netherlands.
5 Department of Gynaecology, Bergman Clinics, Amsterdam, The Netherlands.
6 Department of Obstetrics and Gynaecology, UMCU, University of Utrecht, Utrecht, The Netherlands.
7 Department of Gynaecology, Bergman Clinics, Hilversum, The Netherlands.