Received: 12 November 2021
Accepted: 18 March 2022
First Online: 2 April 2022
: This study was approved by the Ethics Committee of the Tianjin Central Hospital of Obstetrics and Gynecology (Protocol number: ZY2021006). All participating patients signed written informed consents. The research was conducted ethically in accordance with the World Medical Association Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.