[1] Harvard Med Sch, Brigham & Womens Hosp, Dept Obstet & Gynecol, Boston, MA 02115 USA
[2] Yikon Genom Co Ltd, Dept Clin Res, Shanghai 201499, Peoples R China
[3] Peking Univ, Beijing Adv Innovat Ctr Genom, Beijing 100871, Peoples R China
[4] Peking Univ, Biomed Pioneering Innovat Ctr, Beijing 100871, Peoples R China