[1] Univ Edinburgh, Queens Med Res Inst, MRC Ctr Reprod Hlth, Tommys Ctr Maternal & Fetal Hlth, Edinburgh, Midlothian, Scotland
[2] Univ Manchester, Fac Biol Med & Hlth, Sch Med Sci, Tommys Maternal & Fetal Hlth Res Ctr, Manchester, Lancs, England
[3] Cent Manchester Univ Hosp NHS Fdn Trust, Manchester Acad Hlth Sci Ctr, St Marys Hosp, Manchester, Lancs, England
[4] Univ Edinburgh, Usher Inst Populat Hlth Sci & Informat, Ctr Populat Hlth Sci, Edinburgh, Midlothian, Scotland
[5] Scottish Govt, Edinburgh, Midlothian, Scotland
[6] Norwegian Inst Publ Hlth, Div Hlth Serv, Global Hlth Cluster, Oslo, Norway
[7] Rotunda Hosp, Dublin, Ireland
[8] Royal Matern Hosp, Ctr Fetal Med, Belfast, Antrim, North Ireland
[9] Univ Coll Dublin, Natl Matern Hosp, Sch Med, UCD Perinatal Res Ctr, Dublin, Ireland
[10] Royal Infirm Edinburgh NHS Lothian, Dept Neonatol, Edinburgh, Midlothian, Scotland
[11] Royal Coll Midwives, Edinburgh, Midlothian, Scotland
[12] Victoria Charity Ctr, Sands, London, England