Department of Obstetrics Obstetrics and Gynecology Hospital of Fudan University Shanghai 200011 China;
Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases Shanghai 200011 China;
Women's Health and Perinatology Research Group Department of Clinical Medicine UiT-the Arctic University of Norway Tromsφ 9037 Norway;
Institute of Biomedical Sciences Fudan University Shanghai 200032 China;