1. Department of Obstetrics and Gynecology, Fourth Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
2. Department of Obstetrics, Jiangxi Maternal and Child Health Hospital, Nanchang, Jiangxi, China
3. Department of Pathology, Jiangxi provincial People's Hospital Affiliated to Nanchang University, Nanchang, Jiangxi, China
4. Department of Obstetrics and Gynecology, Medical College of Nanchang University, Nanchang, Jiangxi, China
5. Department of Obstetrics and Gynecology, Jiangxi provincial People's Hospital Affiliated to Nanchang University, Nanchang, Jiangxi, China