[1] Mid Sweden Univ, Dept Nursing, Holmgatan 12, S-85170 Sundsvall, Sweden
[2] Uppsala Univ, Dept Womens & Childrens Hlth, Uppsala, Sweden
[3] Res Grp Maternal Reprod & Childrens Hlth, Fac Hlth Sci, Oslo, Norway
[4] Akershus Univ, Coll Appl Sci, Oslo, Norway
[5] Copenhagen Univ Hosp, Rigshosp, Res Unit,Womens & Childrens Hlth, Juliane Marie Ctr Women Children & Reprod, Copenhagen, Denmark
[6] Oslo Univ Hosp, Clin Genet Unit, N-0450 Oslo, Norway
[7] Reg Sealand Homebirth Assoc, Soro, Denmark
[8] Univ Iceland, Fac Nursing, Dept Midwifery, Reykjavik, Iceland
[9] Karolinska Inst, Dept Womens & Childrens Hlth, Div Reprod Hlth, Stockholm, Sweden
[10] Univ Gothenburg, Dept Hlth & Care Sci, Sahlgrenska Akad, Gothenburg, Sweden