1
Department of Clinical Nursing, School of Nursing, Army Medical University, 400038 Chongqing, China
2
Department of Ultrasound, the Second Affiliated Hospital, Army Medical University, 400037 Chongqing, China
3
Department of Obstetrics and Gynecology, DaPing Hospital, Army Medical Univerity, 400042 Chongqing, China
4
Department of Laboratory Diagnosis, School of Laboratory Medicine, Beihua University, 132013 Jilin, Jilin, China
5
Department of Laboratory Diagnosis, Associated Hospital, Beihua University, 132013 Jilin, Jilin, China