[1] Ctr Human Reprod, Div Labs, New York, NY USA
[2] Univ Edinburgh, Obstet & Gynaecol, Edinburgh, Midlothian, Scotland
[3] Univ Aberdeen, Aberdeen Matern Hosp, Sch Med & Dent, Reprod Med, Aberdeen, Scotland
[4] Univ Aberdeen, Aberdeen Matern Hosp, Sch Med & Dent, Div Appl Hlth Sci, Aberdeen, Scotland
[5] Univ Aberdeen, Aberdeen Matern Hosp, Sch Med & Dent, Inst Appl Hlth Sci, Aberdeen, Scotland
[6] Maastricht Univ, Med Ctr, Dept Obstet & Gynecol, Maastricht, Netherlands
[7] Univ Aberdeen, Div Appl Hlth Sci, Med Stat Team, Aberdeen, Scotland
[8] Univ Amsterdam, Acad Med Ctr, Ctr Voortplantingsgeneeskunde, Amsterdam, Netherlands
[9] Maggiore Policlin Hosp, IRCCS Ca Granda Fdn, Clin Ostet & Ginecol, Milan, Italy
[10] Univ Edinburgh, Ctr Reprod Biol, Edinburgh, Midlothian, Scotland
[11] Maggiore Policlin Hosp, IRCCS Ca Granda Fdn, Via M Fanti 6, I-20122 Milan, Italy
[12] Univ Klinikum Schleswig Holstein, Klin Frauenheilkunde & Geburtshilfe, Campus Lubeck, Lubeck, Germany
[13] Liverpool Womens Hosp, Dept OB GYN, Liverpool, Merseyside, England
[14] Sahlgrens Univ Hosp, Reprod Med, Gothenburg, Sweden
[15] Univ Helsinki, Helsinki Univ Hosp, Dept Obstet & Gynaecol, Helsinki, Finland
[16] Vrije Univ Brussel, Univ Ziekenhuis, Ctr Reprod Med, Brussels, Belgium