1. Department of Obstetrics and Gynecology, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu, China
2. Department of Obstetrics and Gynecology, Nanjing Maternity and Child Health Care Hospital, Women’ s Hospital of Nanjing Medical University, 123 Tianfeixiang, Mochou Road, Qinhuai District, Nanjing 210004, Jiangsu, China
3. Department of Obstetrics and Gynecology, Taizhou Maternity Hospital Affiliated to Nantong University, Taizhou 225300, Jiangsu, China