Received: 25 January 2021
Accepted: 5 October 2021
First Online: 26 October 2021
: Ethical approval was obtained from the ethical committees of The Third Affiliated Hospital of Guangzhou Medical University, Guangdong, People’s Republic of China. Informed consent from all subjects was obtained at the Department of Prenatal Diagnosis of The Third Affiliated Hospital of Guangzhou Medical University. Patient records/information were anonymized and deidentified before analysis. All methods in this study were performed in accordance with the Declaration of Helsinkithe and relevant regulations.
: Not applicable.
: The authors declare that they have no competing interests.