About the Authors

Jing Zhao

Contributed equally to this work with: Jing Zhao, Tian Tian

Affiliation Reproductive Medicine Center, Xiangya Hospital, Central South University, Changsha, Hunan, China

Tian Tian

Contributed equally to this work with: Jing Zhao, Tian Tian

Affiliation Reproductive Medicine Center, Xiangya Hospital, Central South University, Changsha, Hunan, China

Qiong Zhang

Affiliation Reproductive Medicine Center, Xiangya Hospital, Central South University, Changsha, Hunan, China

Yonggang Wang

Affiliation Reproductive Medicine Center, Xiangya Hospital, Central South University, Changsha, Hunan, China

Yanping Li

zhaojing19840427@sina.com

Affiliation Reproductive Medicine Center, Xiangya Hospital, Central South University, Changsha, Hunan, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: JZ TT. Performed the experiments: JZ TT. Analyzed the data: JZ TT. Wrote the paper: JZ TT. Ultrasound examination: TT. Revised the manuscript: JZ TT YW QZ YL. Acquisition of data: JZ. Supervised experiments: YL. Interpretation of data: JZ TT YW QZ. Helped to draft the manuscript: YL. Read and approved the final version of the manuscript: YL JZ TT QZ YW.