[1] Odense Univ Hosp, Dept Obstet & Gynecol, Odense, Denmark
[2] Univ Southern Denmark, Fac Hlth Sci, Dept Clin Res, Odense, Denmark
[3] Univ Southern Denmark, Ctr Evidence Based Med Odense CEBMO, Odense, Denmark
[4] Univ Southern Denmark, Cochrane Denmark, Odense, Denmark
[5] Univ Southern Denmark, Dept Clin Res, Odense, Denmark
[6] Odense Univ Hosp, Open Patient Data Exploratory Network, OPEN, Odense, Denmark
[7] Odense Univ Hosp, Dept Obstet & Gynecol, J B Winslows Vej 4, DK-5000 Odense, Denmark