[1] Karolinska Inst, Dept Clin Sci Intervent & Technol, Stockholm, Sweden
[2] Karolinska Univ Hosp, Dept Neonatal Med, Stockholm, Sweden
[3] Natl Clin Registries RKKP, Danish Clin Qual Program, Aarhus, Denmark
[4] Aarhus Univ Hosp, Dept Paediat, Aarhus, Denmark
[5] Oslo Univ Hosp, Dept Neonatal Intens Care, Clin Paediat & Adolescent Med, Oslo, Norway
[6] Landspitali Univ Hosp, Childrens Hosp Iceland, Dept Neonatal Med, Reykjavik, Iceland
[7] Turku Univ Hosp, Dept Paediat & Adolescent Med, Turku, Finland
[8] Univ Turku, Dept Clin Med, Turku, Finland
[9] Aalborg Univ Hosp, Dept Obstet & Gynaecol, Thisted, Denmark
[10] Umea Univ, Dept Clin Sci, Paediat, Umea, Sweden
[11] THL Finnish Inst Hlth & Welf, Dept Knowledge Brokers, Helsinki, Finland
[12] Karolinska Inst, Dept Womens & Childrens Hlth, Stockholm, Sweden
[13] UiT The Arctic Univ Norway, Fac Hlth Sci, Paediat Res Grp, Tromso, Norway
[14] Univ Hosp North Norway, Dept Paediat & Adolescence Med, Tromso, Norway
[15] Univ Helsinki, New Childrens Hosp, Paediat Res Ctr, Dept Paediat, Helsinki, Finland
[16] Helsinki Univ Hosp, Helsinki, Finland
[17] Univ Oslo, Inst Clin Med, Med Fac, Oslo, Norway
[18] Univ Hosp Copenhagen, Dept Intens Care Newborns & Small Children, Copenhagen, Denmark