1 Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, Guangdong, China.
2 Key Laboratory for Major Obstetric Diseases of Guangdong Province, Guangzhou, 510150, Guangdong, China.
3 Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, Guangdong, China. hefangjnu@126.com.
4 Key Laboratory for Major Obstetric Diseases of Guangdong Province, Guangzhou, 510150, Guangdong, China. hefangjnu@126.com.
5 Guangzhou Medical Centre for Critical Pregnant Women, Guangzhou, 510150, Guangdong, China. hefangjnu@126.com.