1. Leicester Royal Infirmary; University Department of Obstetrics and Gynaecology, Fetal and Maternal Medicine Unit; Infirmary Square Leicester UK LE1 5WW
2. Gynuity Health Projects; 15 East 26th St, Suite 801 New York USA 10010
3. Queen's Medical Centre, Nottingham University Hospital; Department of Obstetrics and Gynaecology; Derby Road Nottingham Nottinghamshire UK NG7 2UH
4. London School of Hygiene & Tropical Medicine; Clinical Trials Unit; Keppel Street London UK WC1E 7HT
5. The University of Liverpool; Department of Women's and Children's Health; First Floor, Liverpool Women's NHS Foundation Trust Crown Street Liverpool UK L8 7SS