Affiliation: | 1.Department of Central Laboratory, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, People’s Republic of China ;2.Department of Ultrasound, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, People’s Republic of China ;3.Department of Reproductive Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, People’s Republic of China ;4.Nuffield Department of Women’s and Reproductive Health, University of Oxford, John Radcliffe Hospital, Oxford, UK ; |