1. Department of Reproductive Medicine Center, The Affiliated Weihai Second Municiple Hospital of Qingdao University, Weihai, China;
2. Department of Obstetrics and Gynecology, The Affiliated Weihai Second Municiple Hospital of Qingdao University, Weihai, China;
3. Department of Reproductive Medicine, Dezhou People’s Hospital, Dezhou, China