[1] Uppsala Univ, Dept Womens & Childrens Hlth, S-75185 Uppsala, Sweden
[2] Karolinska Inst, Dept Womens & Childrens Hlth, Stockholm, Sweden
[3] Umea Univ, Dept Clin Hlth Obstet & Gynecol, Umea, Sweden
[4] Univ Orebro, Dept Obstet & Gynecol, Orebro, Sweden
[5] Karolinska Inst, Sodersjukhuset, Dept Clin Sci & Educ, Stockholm, Sweden
[6] Linkoping Univ, Dept Obstet & Gynaecol, Linkoping, Sweden
[7] Linkoping Univ, Dept Clin & Expt Med, Linkoping, Sweden
[8] Gothenburg Univ, Sahlgrenska Univ Hosp, Sahlgrenska Acad, Dept Obstet & Gynecol, Gothenburg, Sweden