1. Obstetrics and Gynaecology; University Medical Centre Utrecht; Utrecht The Netherlands
2. Julius Centre for Health Sciences and Primary Care; University Medical Centre Utrecht; Utrecht The Netherlands
3. Obstetrics and Gynaecology; Academic Medical Centre; Amsterdam The Netherlands
4. Department of Medicine; Stanford Prevention Research Centre; Stanford University; Stanford CA USA
5. Obstetrics and Gynaecology; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
6. Consultant Maternal Fetal Medicine Service; Auckland District Health Board; Auckland New Zealand
7. Obstetrics and Gynaecology; University Medical Centre Auckland; Auckland New Zealand
8. Obstetrics and Gynaecology; Stanford University Medical School; Stanford CA USA
9. Obstetrics and Gynaecology; University of Washington; Washington DC USA
10. Obstetrics and Gynaecology; National University of Malaysia Medical Center; Cheras Malaysia
11. Obstetrics and Gynaecology; Trakya University; Edime Turkey
12. School of Paediatrics and Reproductive Health; University of Adelaide; Adelaide SA Australia