[1]乐杰.妇产科学[M].6版.北京:人民卫生出版社,2005:9091.
[2]李治安.临床超声影像学[M].北京:人民卫生出版社,2003:1439.
[3]郑筱萸.中药新药临床研究指导原则[M].北京:中国医药科学技术出版社,2002:253258.
[4]Pinborg A,Lidegaard O,la Cour Freiesleben N,et al. Consequences of vanishing twins in IVF/ICSI pregnancies[J]. Hum Reprod, 2005,20(10):28212829.
[5]Petra De Sutterl, Julie Bontinck, Valerie Schutysers,et al.Firsttrimester bleeding and pregnancy outcome in singletons after assisted reproduction[J].Hum Reprod,2006,21(7):19071911.