1. Department of Obstetrics, Gynecology and Reproductive Sciences; Yale Stem Cell Center; Yale University School of Medicine; New Haven, CT USA
2. Clinical Department; School of Medicine; Northwest University for Nationalities; Lanzhou, Gansu, P.R. China
3. Obstetrics and Gynecology Department; Third Xiangya Hospital of Central South University; Changsha, Hunan, P.R. China
4. Department of Obstetrics and Gynecology; Shengjing Hospital; China Medial University; Shengyang, Liaoning, P.R. China
5. Biostatistics Program; School of Biological and Population Health Sciences; Oregon State University; Corvallis, OR USA
6. Department of Epidemiology; University of Kentucky; Lexington, KY USA
7. Department of Obstetrics and Gynecology; Division of Gynecologic Oncology; University of Kentucky; Lexington, KY USA
8. Department of Pathology; Yale University School of Medicine; New Haven, CT USA