Gynaecology and obstetrics,Changhai Hospital,Second Military M edical University,Gynaecology and obstetrics,Changhai Hospital,Second Military M edical University,Gynaecology and obstetrics,Changhai Hospital,Second Military M edical University
Supported by Key Project of Shanghai Science and Technology Committee (12411950300), the "1255" Project of Changhai Hospital of Second Military Medical University (CH125510105), and the Joint Research Program for Management of Key Diseases by Shanghai Public Health System (2013ZYJB0201).