About the Authors

Lili Yu

Contributed equally to this work with: Lili Yu, Kai Chang

Affiliation Department of Obstetrics and Gynecology, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing, China

Kai Chang

Contributed equally to this work with: Lili Yu, Kai Chang

Affiliation Department of Laboratory Medicine, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing, China

Jian Han

Affiliation Department of Obstetrics and Gynecology, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing, China

Shaoli Deng

chenming1971@yahoo.com (MC); DengSL072@yahoo.com.cn (SD)

Affiliation Department of Laboratory Medicine, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing, China

Ming Chen

chenming1971@yahoo.com (MC); DengSL072@yahoo.com.cn (SD)

Affiliation Department of Laboratory Medicine, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the meta-analysis: MC LY KC. Performed a systematic electronic search of databases and extracted the data: LY KC MC. Screened titles and abstracts of all studies for relevancy: LY JH MC. Assessed the quality of included studies: LY SD MC. Analyzed the data: LY KC JH. Wrote the paper: LY MC KC.