Funding for this research was provided by:
National Basic Research Program of China (973 Program) (2017YFC1001100)
National Natural Science Foundation of China (81771541, 81701404)
Science Foundation for Distinguished Young Scholars of Shandong (JQ201720)
Text and Data Mining valid from 2020-05-04
Received: 22 January 2020
Accepted: 24 April 2020
First Online: 4 May 2020
Ethics approval and consent to participate
: This study was approved by the ethics committees of Reproductive Medical Center of Shandong University. Each patient has signed an informed consent on obtaining and analyzing their clinical data prior to the initiation of IVF/ICSI-ET treatment.
: Not applicable.
: The authors declare that they have no competing interests.