[1] Shanghai Jiao Tong Univ, Int Peace Matern & Child Hlth Hosp, Sch Med,Key Laboratory of Embryo Original Diseases, Dept Gynecol, Shanghai, Peoples R China
[2] Fudan Univ, Huashan Hosp, Inst Biomed Sci, Shanghai Med Coll,Shanghai Publ Hlth Clin Ctr, Shanghai, Peoples R China
[3] Fudan Univ, Huashan Hosp, Inst Biomed Sci, Shanghai Med Coll, Shanghai, Peoples R China
[4] Fudan Univ, Jinshan Hosp, Dept Obstet & Gynecol, Shanghai, Peoples R China
[5] Soochow Univ, Dept Obstet & Gynecol, Affiliated Hosp 2, Suzhou, Peoples R China
[6] Kings Coll London, Sch Life Course & Populat Sci, Dept Populat Hlth Sci, London, England