Funding for this research was provided by:
the National Natural Science Foundation of China (81672002)
The Jiangsu Provincial Department of Health (H201537)
the Jiangsu Provincial Department of Health (YXZXB2016004)
the Science and Technology Department of Jiangsu Province (BK20161105)
Text and Data Mining valid from 2018-07-06
Received: 14 March 2018
Accepted: 2 July 2018
First Online: 6 July 2018
Ethics approval and consent to participate
: The study, including the informed consent form, was approved by the institutional ethics review committee of Zhenjiang Fourth People’s Hospital, Taixing People’s Hospital, and Nanjing Drum Tower Hospital, respectively, and was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. Written informed consent was obtained from each participant woman.
: Not applicable.
: The authors declare that they have no competing interests.
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