1. Department of Obstetrics and Gynecology, Center for Reproductive Medicine, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
2. Department of Obstetrics and Gynecology, Third Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325200, P.R. China
3. Department of Endocrinology, Third Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325200, P.R. China