About the Authors

Shikai Liu

Affiliation Department of Obstetrics & Gynaecology, Cangzhou Central Hospital, Hebei, 061001, China

Lili Song

commasll@163.com

Affiliation Department of Obstetrics & Gynaecology, Cangzhou Central Hospital, Hebei, 061001, China

Hairong Yao

Affiliation Department of Obstetrics & Gynaecology, Cangzhou Central Hospital, Hebei, 061001, China

Liang Zhang

Affiliation Department of Obstetrics & Gynaecology, Cangzhou Central Hospital, Hebei, 061001, China

Dongkui Xu

Affiliation Department of Obstetrics & Gynaecology, Cangzhou Central Hospital, Hebei, 061001, China

Fangyuan Gao

Affiliation Department of Obstetrics & Gynaecology, Cangzhou Central Hospital, Hebei, 061001, China

Qian Li

Affiliation Department of Obstetrics & Gynaecology, Cangzhou Central Hospital, Hebei, 061001, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceptualization: SL LS. Data curation: DX FG QL. Formal analysis: HY LZ DX FG QL. Funding acquisition: SL LS. Investigation: HY LZ DX FG QL. Methodology: SL LS HY LZ DX. Project administration: SL LS. Resources: SL LS. Software: FG QL. Validation: LZ DX FG. Writing – original draft: SL LS HY. Writing – review & editing: SL LS HY.