1 Center for Reproductive Medicine, Department of Ultrasound Medicine, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, China 310014.
2 Center for Reproductive Medicine, Department of Gynecology, Zhejiang Provincial People's Hospital, (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, China 310014.
3 Center for Reproductive Medicine, Department of Gynecology, Zhejiang Provincial People's Hospital, (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, China 310014; Key Laboratory of Endocrine Gland Diseases of Zhejiang Province, 310014, Hangzhou, Zhejiang, China. Electronic address: wjzeng8524@163.com.