1. Departments of Laboratory Medicine and Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
2. Department of Obstetrics and Gynecology, Zhenjiang Fourth People’s Hospital, Zhenjiang, Jiangsu, China
3. Department of Obstetrics and Gynecology, Nanjing Drum Tower Hospital, Nanjing, China
4. Department of Mass Health Care, Sihong County Maternal and Child Health Hospital, Sihong, Jiangsu, China
5. Department of Mass Health Care, Rugao Municipal Center for Maternal and Child Health Care and Family Planning, Jiangsu, Jiangsu, China
6. Department of Obstetrics and Gynecology, Wujin Hospital, Changzhou, Jiangsu, China
7. Department of Mass Health Care, Nantong Municipal Maternal and Child Health Hospital, Nantong, Jiangsu, China