Received: 4 February 2021
Accepted: 20 April 2021
First Online: 30 April 2021
: Informed consent was obtained from all participants. This study was approved by the Ethics Committee of Maternal and Child Health Care Hospital in Chongqing, China.We confirm that all methods were carried out in accordance with relevant guidelines and regulations.
: Not applicable.
: The authors declare that they have no competing interests.