1. Center for Reproductive Medicine, Affiliated Hospital 1 of Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
2. School of 2nd Clinical Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
3. School of 1st Clinical Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China
4. Department of Histology & Embryology, School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, P. R. China