[1] Klin Hammerfest, Dept Gynaecol, N-9613 Hammerfest, Norway
[2] Univ Oslo, Fac Med, Oslo, Norway
[3] Ullevaal Univ Hosp, Dept Gynaecol, Women & Childrens Div, Oslo, Norway
[4] GynMed Clin, Vienna, Austria
[5] Univ Helsinki, Dept Obstet & Gynaecol, Helsinki, Finland
[6] Univ Cent Hosp, Katiloopisto Hosp Helsinki, Helsinki, Finland
[7] Karolinska Inst, Dept Clin Sci & Educ, Stockholm, Sweden
[8] Karolinska Inst, Dept Womens & Childrens Hlth, Div Obstet & Gynaecol, Stockholm, Sweden