2Nicolaides KH, Brizot ML, Snijders RJM. Fetal nuchal translucency: ultrasound screening for fetal trizomy in the first trimester of pregnancy[J]. B JOG, 1994,101:782-786.
3Cicero S, Curcio P, Papageorghiou A, et al. Absence of nasal bone in fetuses with trisomy 21 at 11-14 weeks of gestation: an observational study[J]. Lancet, 2001,358:1665-1667.
4Borenstein M, Persico N, Dagklis T, et al. Frontomaxillary facial angle in fetuses with trisomy 13 at 11 + 0 to 13 + 6 weeks[J]. Ultrasound Obstet Gynecol, 2007,30:819-823.
5Nicolaides KH. Nuchal translucency and other first-trimester sonographic markers of chromosomal abnormalities[J]. Am J Obstet Gynecol, 2004,191:45-67.
6Borrell A, Grande M, Bennasar M, et al. First-trimester detection of major cardiac defects with the use of ductus venosus blood flow[J]. Ultrasound Obstet Gynecol, 2013, 42: 51-57.
7Geipel A,Gembruch U. Screening performance of first trimester nuchal translucency, ductus venosus blood flow and tricuspid regurgitation for cardiac defects[J]. Z Geburtshilfe Neonatol, 2012,216:157-161.
8Molina F, Persico N, Borenstein M, et al. Frontomaxillary facial angle in trisomy 21 fetuses at 16-24 weeks of gestation[J]. Ultrasound Obstet Gynecol, 2008,31:384-387.
9Pan M, Chen M, Sahota DS, et al. Can we use the frontomaxillary facial angle in the first trimester to predict facial cleft? [J]. Prenat Diagn, 2012,32:491-493.
10Chaoui R, Benoit B, Mitkowska-Wozniak H, et al. Assessment of intracranial trans|ucency (IT)in the detection of spina bifida at the 11-13weeks scan[J].Uhrasound Obstet Gynecol, 2009,34: 249-252.