1. Radboud University Medical Center, Obstetrics and Gynaecology , Nijmegen, The Netherlands
2. Nij Geertgen, Center for Fertility, Elsendorp , The Netherlands
3. University Medical Center Utrecht, Fertility Unit- Division Mother and Child , Utrecht, The Netherlands
4. Nij Barrahûs, Center for Fertility, Wolvega , The Netherlands
5. Jeroen Bosch Ziekenhuis, Gynaecology, 's-Hertogenbosch , The Netherlands
6. Isala, Isala Fertility Center, Zwolle , The Netherlands
7. MUMC+, Center for Reproductive Medicine, Maastricht , The Netherlands
8. Diakonessenhuis, Gynaecology , Utrecht, The Netherlands
9. Hospital Gelderse Vallei, Gynaecology , Ede, The Netherlands
10. University Medical Center Groningen, Section of Reproductive Medicine- Department of Obstetrics and Gynecology , Groningen, The Netherlands
11. NoordWest Ziekenhuisgroep, Obstetrics- Gynaecology- and Reproductive Medicine , Alkmaar, The Netherlands
12. Maxima Medical Center, Obstetrics and Gynaecology , Veldhoven/Eindhoven, The Netherlands
13. Haga Ziekenhuis, Gynaecology , Den Haag, The Netherlands
14. Gelre Hospital, Gynaecology , Apeldoorn, The Netherlands
15. Amphia Ziekenhuis, Obstetrics and Gynaecology , Breda, The Netherlands
16. Amsterdam UMC - VUmc, IVF center, Amsterdam , The Netherlands
17. OLVG, Obstetrics and Gynaecology , Amsterdam, The Netherlands
18. Leiden University Medical Center, Gynaecology , Leiden, The Netherlands
19. Elisabeth-TweeSteden hospital, Center of Reproduction, Tilburg , The Netherlands
20. Haaglanden Medical Center, Gynaecology , Den Haag, The Netherlands
21. Amsterdam UMC location University of Amsterdam, Center for Reproductive Medicine, Amsterdam , The Netherlands