1. Department of Haematology Oxford University Hospitals Oxford UK
2. Women's Health Research Unit Centre for Primary Care and Public Health WHO Collaborating Centre Blizard Institute London UK
3. Department of Obstetrics and Gynaecology Guys and St Thomas' NHS Foundation Trust London UK
4. Haematology Department Guys and St Thomas' NHS Foundation Trust London UK
5. NHSBT/Department of Haematology John Radcliffe Hospital Oxford UK
6. Department of Obstetrics and Gynaecology West Middlesex University Hospital and Chelsea & Westminster Hospital London UK