1. Department of Reproductive Medicine and Gynaecology, University Medical Centre Utrecht, Utrecht University, Heidelberglaan, CX Utrecht, The Netherlands
2. Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Utrecht University, Heidelberglaan, CX Utrecht, The Netherlands
3. Department of Reproductive Medicine, Maastricht University Medical Centre, P. Debyelaan 25, HX Maastricht, The Netherlands
4. Centre for Reproductive Medicine, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, GZ Groningen, The Netherlands
5. Centre for Reproductive Medicine, Amsterdam University Medical Centre, Free University of Amsterdam, De Boelelaan, HV Amsterdam, The Netherlands
6. Department of Obstetrics and Gynaecology, Jeroen Bosch Hospital, Henri Dunantstraat 1, GZ 's-Hertogenbosch, The Netherlands
7. Department of Obstetrics and Gynaecology, Radboud University Medical Centre, Geert Grooteplein Zuid 10, GA Nijmegen, T he Netherlands
8. Centre for Reproductive Medicine, Amsterdam University Medical Centre, University of Amsterdam, Meibergdreef 9, AZ Amsterdam, The Netherlands
9. Department of Obstetrics and Gynaecology, Isala Clinics, Dokter Spanjaardweg 27-29, 8025 BT Zwolle, The Netherlands
10. Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynaecology, Erasmus University Medical Centre, Doctor Molewaterplein 40, 3015 GD Rotterdam, The Netherlands
11. Department of Obstetrics and Gynaecology, Monash University, Scenic Blvd & Wellington Road, Clayton, VIC, Australia