Department of Obstetrics, Hanchuan Hospital, Wuhan University People's Hospital, Hanchuan 431600, China;
Department of Gynecology, Wuhan University People's Hospital, Wuhan 430060, China;
Department of Obstetrics, Hanchuan Hospital, Wuhan University People's Hospital, Hanchuan 431600, China;
Department of Obstetrics, Hanchuan Hospital, Wuhan University People's Hospital, Hanchuan 431600, China;