Funding for this research was provided by:
Changzhou Science and Technique Program (CJ20190098)
Received: 4 January 2020
Accepted: 29 June 2020
First Online: 13 July 2020
Ethics approval and consent to participate
: The study complied with the Declaration of Helsinki and was reviewed and approved by the Human Subjects Committee of Changzhou No.2 People’s Hospital approved this study. Written informed consent was obtained from each couple enrolled in the study.
: This manuscript does not include any individual person’s data.
: The authors declare there were no Competing interests.