1. Institute for Women's Health University College London London UK
2. Center for Reproductive Medicine Amsterdam University Medical Center Amsterdam the Netherlands
3. Amsterdam Reproduction and Development Research Institute Amsterdam University Medical Center Amsterdam the Netherlands
4. Obstetrics and Gynecology Amsterdam University Medical Center Amsterdam the Netherlands
5. The Ritchie Centre, Department of Obstetrics and Gynecology Monash University Clayton Victoria Australia
6. Aberdeen Centre for Women's Health Research, School of Medicine, Medical Sciences and Nutrition University of Aberdeen Aberdeen UK
7. Early Pregnancy and Gynaecology Assessment Unit King's College London Hospital London UK