1. Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
2. Department of Obstetrics and Gynecology, Tongren Hospital of Wuhan University (Wuhan Third Hospital), Wuhan, Hubei 430022, P.R. China
3. University Clinic for Medical Radiation Physics, Medical Campus Pius‑Hospital, Carl von Ossietzky University, Oldenburg D‑26121, Germany