1Shipp T, Benacerraf BR. Second trimester ultrasound screening for chromosomal abnormalities [ J ]. Prenat Diagn, 2002,22 : 296 -307.
2Gianferrari EA, Benn PA, Dries L, et al. Absent Or shortened nasal bone length and the detection' of down syndrome in the second trimester [ J]. Obstet Gyneeol,2007, 108:371-374.
4Benn PA, Egan JF. Expected performance of second trimester materrial serum testing followed by agenetic sonogram in screening of fetal Down syndrome [ J ]. Prenat Diagn, 2008,28 : 230-235.
4Zaragoza MV,Surti U,Redline Rw,et al.Prenatal origin and phenotype of triploidy in spontaneous abortion:predominance of diandry and association with partial hydatidformmole[J].Am J Hum Genet,2000,66:1807-1820.
5Nicolaids KH,Snijders R J,Gosdan CM,et al.Ultrasonographically detectable markers of fetal chromosomal abnormali ties[J].Lancet,1992,340:704-707.
6陈嫦佩,陆兆龄.围产期超声多普勒诊断学[M].北京:人民卫生出版社,2002.73-80.
7Muller F, Forestier F, Dingeon B. Second trimester trisomy 21 maternal serum marker screening. Results of a countrywide study of 854902 patients. Prenat Diagn, 2002, 22 : 925-929.
8ACOG Practice Bulletin, No,27, May 2001 Prenatal diagnosis of fetal chromosome abnormalities. Washington DC,20024-2188.
9Phillips O P, Elias S, Shulman L, et al. Maternal serum screening for fetal Down syndrome in women less than 35 years of age using alpha- fetoprotein, HCG, and uE3 :a prospective 2-year study. Obstet Gynecol, 1992, 80: 353-358.
10Spencer K. Second trimester prenatal screening for Down syndrome using alpha-fetoprotein and free beta HCG: a seven year review. Br J Obstet Gynecol, 1999, 106-1287-1293.
