1Nicolaides KH, et al. Fetal nuchal translucency:ultrasound screening for chromosomal defects in first trimester of pregnancy[S] BMJ, 1992,304(6831):867- 869.
3Whitlow BJ, Economides DL. The optimal geststional age to examine fetal anatomy and measure nucha translucency in the first trimester[J].Ultrasound Obstel 6ynecol, 1998,11(4):258 -261.
4Kaisenberg CS, Prols F,Nicolaides KH, et al. Glycosaminogtycans and proteoglycans in the skin of aneuploid fetuses with increasednucha 1 t rans lucency [J] . Hum Reprod, 2003, 18:2544 - 2561.
8Souka hP, et al. Increased nuchal translucency with normal karyotype[J].Am J Obstet 6ynecol, 2005, 192 (4) : 1005 - 1021.
9Hyett J, Perdu M, Sharland G, et al. Using fetal nuchal translucency to screen for major congenital cardic defect at 10-14 weeks of gestation: study [J]. ppopulati BMJ, 1999, on based cohort 318 (7176): 81 - 85.
10Souka A1J, yon Kaisenberg CS, Hyett JA, et al. Increased nuchal transluccency normal karyotype [J].AM Jobstet 6ynecol,2004,192(4):lO05-1021.
5Cicero 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.Lancet,2001,358:1665-1667.
6Otano L,Aiello H,Igarzabal L,et al.Association between first trimester absence of fetal nasal bone on ultrasound and Down syndrome.Prenat Diagn,2002,22 :930-932.
7Wong SF,Choi H,Ho LC.Nasal bone hypoplasia:is it a common finding amongst chromosomally normal fetuses of southern Chinese women? Gynecol Obstet Invest,2003,56:99-101.
8Chen M,Lee CP,Leung KY,et al.Pilot study on the midsecond trimester examination of fetal nasal bone in the Chinese population.Prenat Diagn,2004,24:87-91.
9Sandikcioglu M,Molsted K,Kjaer I.The prenatal development of the human nasal and volemar bones.J Craniofac Genet Dev Biol,1994,14:124-134.
10Sonek JD,McKenna D,Webb D,et al.Nasal bone length throughout gestation:normal ranges based on 3537 fetal ultrasound measurements.Ultrasound Obstet Gynecol,2003,21:152-155.
