[1] Sichuan Univ, West China Univ Hosp 2, Reprod Med Ctr, Dept Obstet & Gynecol, Chengdu 610041, Sichuan, Peoples R China
[2] Sichuan Univ, West China Univ Hosp 2, Key Lab Birth Defects & Related Women & Children, Minist Educ, Chengdu 610041, Peoples R China
[3] Sichuan Univ, West China Sch Med, Chengdu 610041, Peoples R China
[4] Sichuan Univ, West China Univ Hosp 2, SCU CUHK Joint Lab Reprod Med, Chengdu 610041, Sichuan, Peoples R China