Li Xiaotian, Gu Yu, Zhu Lei, Cheng Weiwei, Pan Mingming, Zhuang Yiliang
Department of Maternal-Fetal Medicine, The Obstetrics and Gynecology Hospital, Fudan Univeristy, Shanghai, China.
Acta Obstet Gynecol Scand. 2006;85(12):1510-1. doi: 10.1080/00016340600609012.