[1] Univ Helsinki, Med & Clin Genet, FI-00014 Helsinki, Finland
[2] Univ Helsinki, Helsinki Univ Hosp, POB 63, FI-00014 Helsinki, Finland
[3] Univ Turku, Dept Obstet & Gynaecol, POB 52, FI-20521 Turku, Finland
[4] Turku Univ Hosp, POB 52, FI-20521 Turku, Finland
[5] Univ Turku, Dept Clin Med, Biostat, FI-20014 Turku, Finland
[6] Univ Turku, Turku Univ Hosp, FI-20014 Turku, Finland
[7] Vita Healthcare Serv Ltd, Laivakatu 5 F, FI-00150 Helsinki, Finland
[8] Univ Helsinki, Dept Clin Chem, Helsinki, Finland
[9] Natl Inst Hlth & Welf, Chron Dis Prevent Unit, FI-00271 Helsinki, Finland
[10] Univ Helsinki, Hosp Children & Adolescents, Stenbackinkatu 11,POB 281, FI-00029 Helsinki, Finland
[11] Helsinki Univ Hosp, Stenbackinkatu 11,POB 281, FI-00029 Helsinki, Finland
[12] Oulu Univ Hosp, MRC Oulu, PEDEGO Res Unit, Oulu 90014, Finland
[13] Univ Oulu, Oulu 90014, Finland
[14] Univ Helsinki, Dept Psychol & Logoped, POB 63, FI-00014 Helsinki, Finland
[15] Univ Helsinki, Fac Med, POB 63, FI-00014 Helsinki, Finland
[16] Terveystalo Oy, Asemakatu 22-24, FI-70100 Kuopio, Finland
[17] Univ Helsinki, Obstet & Gynaecol, Haartmaninkatu 2,POB 140, FI-00029 Helsinki, Finland
[18] Helsinki Univ Hosp, Haartmaninkatu 2,POB 140, FI-00029 Helsinki, Finland
[19] Univ Helsinki, Helsinki Inst Life Sci, Inst Mol Med Finland FIMM, POB 20, FI-00014 Helsinki, Finland
[20] Tampere Univ Hosp, Dept Obstet & Gynecol, POB 2000, FI-33521 Tampere, Finland
[21] Univ Tampere, Fac Med & Life Sci, POB 100, FI-33014 Tampere, Finland