About the Authors

Lianzhi Qin

Roles Conceptualization, Investigation, Methodology, Supervision, Validation, Visualization, Writing – original draft

Affiliation Delivery room, Linyi Central Hospital, Linyi, Shandong, China

Ting Li

Roles Data curation, Formal analysis, Investigation, Methodology, Software, Validation, Visualization, Writing – original draft

Affiliation Department of Gynecology, Zoucheng People’s Hospital, Zoucheng, Shandong, China

Yuhua Liu

Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Writing – review & editing

yuhualiu1@foxmail.com

Affiliation Department of Obstetrics, Anqiu People’s Hospital, Anqiu, Shandong, China

Competing Interests

The authors have declared that no competing interests exist.