[1] Univ Hosp Leuven, Dept Obstet & Gynecol, Leuven, Belgium
[2] Katholieke Univ Leuven, Dept Dev & Regenerat, Leuven, Belgium
[3] Katholieke Univ Leuven, Dept Publ Hlth & Primary Care, Leuven, Belgium
[4] Skane Univ Hosp, Dept Obstet & Gynecol, Malmo, Sweden
[5] Lund Univ, Dept Clin Sci, Malmo, Sweden
[6] Maastricht Univ, CAPHRI Care & Publ Hlth Res Inst, Dept Epidemiol, Maastricht, Netherlands
[7] Hosp Univ Dexeus, Dept Obstet Gynecol & Reprod, Barcelona, Spain
[8] Univ Milan, Clin Sci Inst L Sacco, Dept Obstet & Gynecol, Milan, Italy
[9] Clin Univ Navarra, Dept Obstet & Gynecol, Pamplona, Spain
[10] Univ Hosp Brugmann, Dept Obstet & Gynecol, Brussels, Belgium
[11] Univ Milano Bicocca, San Gerardo Hosp, Clin Obstet & Gynecol, Monza, Italy
[12] Ziekenhuis Oost Limburg, Dept Obstet & Gynecol, Genk, Belgium
[13] Univ Udine, Dept Obstet & Gynecol, Udine, Italy
[14] Med Univ Silesia, Fac Med Sci, Dept Perinatol & Oncol Gynecol, Katowice, Poland
[15] Univ Debrecen, Fac Med, Dept Obstet & Gynecol, Debrecen, Hungary
[16] Univ Athens, Alexandra Hosp, Dept Obstet & Gynecol 1, Sch Med, Athens, Greece
[17] Karolinska Inst, Dept Clin Sci & Educ, Sodersjukhuset, Stockholm, Sweden
[18] Karolinska Inst, Dept Womens & Childrens Hlth, Stockholm, Sweden
[19] Queen Charlottes & Chelsea Hosp, Imperial Coll, London, England