Funding for this research was provided by:
National Natural Science Foundation of China (81571507)
Text and Data Mining valid from 2019-09-05
Received: 13 March 2019
Accepted: 22 August 2019
First Online: 5 September 2019
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of the Reproductive Medicine Center of Xiangya Hospital and registered with Chinese Clinical Trial Registry (registration number: ChiCTR-OOC-17012214).
: Written informed consent for publication was obtained from the patients.
: The authors declare that they have no competing interests.