1. Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
2. Department of Laboratory Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine; Key Laboratory of Clinical In Vitro Diagnostic Techniques of Zhejiang Province; Institute of Laboratory Medicine, Zhejiang University, Hangzhou, Zhejiang 310000, P.R. China