Department of Obstetrics and Gynecology, Chinese PLA General Hospital, Beijing 100853, China;
Department of Obstetrics and Gynecology, Chinese PLA General Hospital, Beijing 100853, China;
Department of Obstetrics and Gynecology, Chinese PLA General Hospital, Beijing 100853, China;
Department of Obstetrics and Gynecology, Chinese PLA General Hospital, Beijing 100853, China;
Department of Obstetrics and Gynecology, Chinese PLA General Hospital, Beijing 100853, China;
Department of Obstetrics and Gynecology, Chinese PLA General Hospital, Beijing 100853, China;
Department of Ultrasound, Chinese PLA General Hospital, Beijing 100853, China;
Department of Obstetrics and Gynecology, Chinese PLA General Hospital, Beijing 100853, China;