1. Record Room, Jinan Second People's Hospital, Jinan 250011, Shandong, China.
2. Department of Obstetrics & Gynaecology, Jinan Second People's Hospital, Jinan 250011, Shandong, China.
3. Department of Traditional Chinese Medicine, Jinan Second People's Hospital, Jinan 250011, Shandong, China.
4. Department of Orthopedics, Shandong Chest Hospital, Jinan 250101, Shandong, China.