[1] Peking Univ Third Hosp, Ctr Reprod Med, Dept Obstet & Gynecol, Beijing 100191, Peoples R China
[2] Peking Univ Third Hosp, Natl Clin Res Ctr Obstet & Gynecol, Beijing, Peoples R China
[3] Peking Univ, Key Lab Assisted Reprod, Minist Educ, Beijing, Peoples R China
[4] Peking Univ Third Hosp, Beijing Key Lab Reprod Endocrinol & Assisted Repr, Beijing, Peoples R China