Funding for this research was provided by:
Tianjin Science and Technology Plan Project (no.21JCYBJC01480, no.21JCYBJC01480)
Received: 28 January 2023
Accepted: 12 August 2023
First Online: 30 August 2023
: This retrospective analysis was exempt from ethics committee approval at Tianjin Medical University, Tianjin Central Hospital of Gynecology and Obstetrics because the committee did not consider approval necessary for a retrospective chart review. Data were collected from the institution's electronic medical records while preserving patient anonymity. The research ethics committee waived the requirement for informed consent because the study used previously stored data. Therefore, administrative permissions were not required to access and use the medical records described in our study.
: Not applicable.
: The authors declare that they have no competing interests.