[1] Oulu Univ Hosp, Dept Obstet & Gynaecol, Oulu, Finland
[2] St George Hosp, Sch Med, Diana Princess Wales Ctr Reprod Med, Acad Dept Obstet & Gynaecol, London, England
[3] Univ Sjukhuset MAS, Dept Obstet & Gynecol, Kvinnoklin, Malmo, Sweden
[4] Fertil Associates, Auckland, New Zealand
[5] Ctr Reprod & Adv Technol, London, England