[1] Odense Univ Hosp, Dept Obstet & Gynaecol, DK-5000 Odense, Denmark
[2] Turku Univ Hosp, Dept Obstet & Gynaecol, FIN-20520 Turku, Finland
[3] Lidkoping Hosp, Dept Obstet & Gynaecol, Lidkoping, Sweden
[4] Ahus Univ Hosp, Dept Obstet & Gynaecol, Ahus, Norway
[5] Lund Univ, Fac Med, Ctr Primary Healthcare Res, Lund, Sweden
[6] Lund Univ, Skane Univ Hosp, Dept Obstet & Gynaecol, Lund, Sweden