1. Center for Reproductive Medicine, The Third Affiliated Hospital, Sun Yat-sen University, 6 East Longkou Road, Guangzhou, China
2. Center for Reproductive Medicine, Jiangmen Central Hospital, Affiliated Jiangmen Hospital of Sun Yat-sen University, Jiangmen, China
3. Department of Reproductive Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
4. Memorial hospital of Sun Yat-sen University, Guangzhou, China