1. Department of Gynecology, Third Xiangya Hospital of Central South University, 138 Tongzipo Road, Changsha, Hunan 410013, China
2. Department of Cardiology, Xiangya Hospital, Central South University, Changsha, Hunan, China
3. Department of OB/GYN, Baylor College of Medicine, 6651 Main Street, 10th Floor, Houston, TX 77030, USA
4. Center for Medical Experiments, Third Xiangya Hospital, Central South University, Changsha, Hunan, China