Affiliation: | 1. Department of Obstetrics and Gynecology, Peking University People's Hospital, Beijing, China;2. Department of Obstetrics and Gynecology, Cangzhou Central Hospital, Cangzhou, China;3. Department of Obstetrics and Gynecology, The Second Hospital of Hebei Medical University, Shijiazhuang, China;4. Laboratory of Cardiovascular Bioactive Molecule, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China;5. Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China |