Department of Obstetrics and Gynecology, the First Affiliated Hospital of Harbin Medical University, Harbin150001, China;
Department of Obstetrics and Gynecology, the First Affiliated Hospital of Harbin Medical University, Harbin150001, China;
Department of Obstetrics and Gynecology, the First Affiliated Hospital of Harbin Medical University, Harbin150001, China;
Department of Obstetrics and Gynecology, the First Affiliated Hospital of Harbin Medical University, Harbin150001, China;