[1] Royal Coll Surg, Dept Obstet & Gynecol, Dublin, Ireland
[2] Royal Coll Surg, Dept Epidemiol & Publ Hlth, Dublin, Ireland
[3] Royal Coll Surg, Dept Neonatol, Dublin, Ireland
[4] Rosie Matern Hosp, Dept Neonatol, Cambridge, England
[5] Queens Univ Belfast, Sch Nursing & Midwifery, Belfast, Antrim, North Ireland
[6] Univ Oxford, Natl Perinatal Epidemiol Unit, Oxford, England
[7] Univ Melbourne, Dept Obstet & Gynecol, Royal Womens Hosp, Melbourne, Vic, Australia
[8] Univ Coll Dublin, Obstet & Gynecol, UCD Perinatal Res Ctr, Natl Matern Hosp, Dublin, Ireland