1 Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK.
2 Department of Haematology, Haemostasis Research Unit, University College London, London, UK.
3 Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
4 Center for Vascular Medicine and Department of Medicine III, University Hospital 'Carl Gustav Carus', Technische Universität Dresden, Dresden, Germany.
5 Department of Obstetrics and Gynaecology, University College London, London, UK.
6 Katharine Dormandy Haemophilia Centre and Thrombosis Unit, The Royal Free Hospital NHS Foundation Trust, London, UK.
7 Department of Obstetrics and Gynaecology, The Royal Free Hospital NHS Foundation Trust, London, UK.