Association of Maternal Longitudinal Hemoglobin with Small for Gestational Age during Pregnancy: A Prospective Cohort Study oleh Shangzhi Xu, Weiming Wang, Qian Li, Li Huang, Xi Chen, Xu Zhang, Xiaoyi Wang, Weizhen Han, Xingwen Hu, Xuefeng Yang, Liping Hao, Guoping Xiong, Nianhong Yang