[1] Barts Hlth NHS Trust, Obstet & Gynaecol, Hlth Educ England London, Royal London Hosp, Ward 6F,Whitechapel Rd, London E1 1BB, England
[2] Barts Hlth NHS Trust, Obstet & Gynaecol ST2, Hlth Educ England London, Royal London Hosp, London, England
[3] Princesa Hosp, Dept Internal Med, Madrid, Spain
[4] Monash Univ, Obstet & Gynaecol, Clayton, Vic, Australia
[5] Imperial Coll London, Neonatal Med, London, England
[6] Natl Univ Ireland Galway, Midwifery, HRB Trials Methodol Res Network, Sch Nursing & Midwifery, Galway, Ireland
[7] Acad Med Ctr, Obstet & Gynaecol, Amsterdam, Netherlands
[8] Univ Hosp Southampton NHS Fdn Trust, Dept Neonatal Med, Princess Anne Hosp, Southampton, Hants, England
[9] Univ Southampton, Natl Inst Hlth Res, Southampton Biomed Res Ctr, Univ Hosp Southampton NHS Fdn Trust, Southampton, Hants, England
[10] Barts Hlth NHS Trust, Royal London Hosp, London, England
[11] Queen Mary Univ London, Maternal & Perinatal Hlth, Womens Hlth Res Unit, Barts & London Sch Med & Dent,Barts Hlth NHS Trus, London, England