1. Department of Obstetrics & Gynaecology, and Centre for Trophoblast Research, University of Cambridge, Cambridge, UK
2. Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
3. Department of Obstetrics, Division of Obstetrics and Gynecology, Oslo University Hospital, Oslo, Norway
4. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
5. Department of Pediatrics, Section of Neonatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA