Text and Data Mining valid from 2019-05-10
Received: 7 December 2018
Accepted: 12 April 2019
First Online: 10 May 2019
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of Reproductive and Genetic Hospital CITIC-Xiangya on November 20, 2014 (LL-SC-SG-2014-014).
: Written informed consent for publication was obtained from all participants.
: The authors declared that they have no conflicts of interest to this work.
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