1. Department of Obstetrics & Gynaecology; Academic Medical Centre; Amsterdam The Netherlands
2. Department of Obstetrics & Gynaecology; Vrije Universiteit Medical Centre; Amsterdam The Netherlands
3. Medical Library; Academic Medical Centre; Amsterdam The Netherlands
4. Department of Obstetrics & Gynaecology; University Medical Centre; Utrecht The Netherlands
5. The Robinson Research Institute, School of Paediatrics and Reproductive Health; University of Adelaide; Adelaide Australia