[1] Harbin Med Univ, Affiliated Hosp 1, Dept Obstet & Gynecol, Harbin, Peoples R China
[2] Seacroft Hosp, Leeds Ctr Reprod Med, Leeds, W Yorkshire, England
[3] Fertil Associates Memphis, Memphis, TN USA
[4] Hong Kong Sanat & Hosp, IVF Ctr, Happy Valley, Hong Kong, Peoples R China
[5] Kaplan Med Ctr, Dept Obstet & Gynecol, Rehovot, Israel
[6] Johns Hopkins Med Inst, Dept Gynecol & Obstet, Baltimore, MD 21205 USA
[7] Harbin Med Univ, Affiliated Hosp 1, Harbin, Peoples R China