1. Department of Obstetrics, The Fourth Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
2. Department of Obstetrics and Gynecology, Zhejiang Hospital, Hangzhou, Zhejiang 310030, P.R. China
3. Hebei Key Laboratory of Integrative Medicine on Liver‑Kidney Patterns, Institute of Integrative Medicine, College of Integrative Medicine, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050200, P.R. China