1. Center for Reproductive Medicine, Academic Medical Center, Amsterdam, The Netherlands
2. Center for Reproductive Medicine, VU Medical Center, Amsterdam, The Netherlands
3. Department of Obstetrics and Gynaecology, Zaans Medisch Centrum, Zaandam, The Netherlands
4. Department of Obstetrics and Gynaecology, Sint Franciscus Gasthuis, Rotterdam, The Netherlands
5. Department of Obstetrics and Gynaecology, Spaarne Gasthuis, Hoofddorp, The Netherlands
6. Department of Obstetrics and Gynaecology, Medical Center Leeuwarden, Leeuwarden, The Netherlands
7. Department of Obstetrics and Gynaecology, Groene Hart Ziekenhuis, Gouda, The Netherlands
8. Department of Obstetrics and Gynecology, Maastricht University Medical Center, Maastricht, The Netherlands
9. Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia