5Carvalho JS.Fetal Heart scanning in the first trimester [J]. PrenatDiagn, 2004,24.. 1060- 1067.
6Gillum RF. Epidemiology of congenital heart disease in the United States. Am Heart J, 1994,127 : 919-927.
7Gembruch U. Prenatal diagnosis of congenital heart disease. Prenat Diagn, 1997,17 : 1283-1298.
8Horger EO,Tsai CC. Ultrasound and the prenatal diagnosis of congenital anomlies~A medicolegal oersoective. Obstet Gynecol, 1989,74:617-619.
9Goncalves LF,Jeanty P, Piper JM. The accuracy of prenatal ultrasonography in detecting congenital anomalies. Am J Obstet Gynecol, 1994,171 : 1606-1612.
10Anderson N,Boswell O,Duff G. Prenatal sonography for the detection of fetal anomalies:Results of a prospective study and comparison with prior series. AJR, 1995,165 : 943-950.