Funding for this research was provided by:
National Natural Science Foundation of China (81801532, 81871211, 81502507)
Received: 16 July 2020
Accepted: 22 October 2020
First Online: 29 October 2020
Ethics approval and consent to participate
: This study was approved by the ethics committee of the Third Affiliated Hospital of Guangzhou Medical University. Since this is a retrospective investigation, patients were not asked to participate in this study. 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.