1MehugoM,Skeletal A,Twining P,et al.Text book of fatal ab-normalities[J].London church ill Livingstone,2000:237-267.
2Baron ciani D,Scaglia C,CorchiaC,et al.Ultsonography in pregnancy and fetal abnormalities screening or diagnostic test[J].Prenat Diagn,1995,15:1101-1108.
1McHugo JM. Skeletal A, Twining P, eds. Textbook of fetal abnormalities. London: Churchill Livingstone,2000. 237-267.
2Baronciani D, Scaglia C, Corehia C, et al. Ultrasonography in pregnancy and fetal abnormalities: screening or diagnostic test?Prenat Diagn, 1995,15:1101-1108.
3Chitty CS, Hunt GH, Moore J, et al. Effectiveness of routine ultrasonography in detecting fetal abnormalities in a low risk population. BMJ, 1991,303:165-169.