1Wald NJ, Hachshaw A, Stone R, et al. Serum PAPP- A levels are elepressed in women with fetal Down's syndrome in early pregnancy. Prenat Diagn, 1993, 13:633-636
2Bersinger NA, Brizot ML, Johnson A, et al. First trimester maternal serum pregnancy associated plasma protein A and pregnancy specific beta 1 - glycoprotein in fetal trisomies. Br J Obstet Gyneeol, 1994, 101:970- 974
3Macintosh MCM, Chard J. Biochemical screening for Down's syndrome in the first trimester of pregnancy. Fetal Matern Med Rev, 1993, 5:181- 190
4Wald NJ, George L, Smith D, et al. Serum screening for Down's syndrome between 8 and 14 weeks of pregnancy. Br J Obstet Gynecol, 1996,103:407 -412
5Merkatz IR, Nitowaky HM, Macri JN, et al. An association between low matenal serum alpha - fetoprotein and fetal chromosomal abnormalities. Am J Obstet Gynecol, 1984, 148:886
6Hsu TT, Hsieh TT. Down syndrome screening in an Asian population using alpha- fetoprotein and free β - hCG: A report of Taiwan Down syndrome screening group. Obstet Gyneeol, 1996, 87:943-947
7Bogart MH, Pandian MR, Jones OW, et al. Abnormal maternal serum chorionic gonadotropin levels in pregnancies with fetal chromosome abnormalities. Prenat Diagn, 1987, 7:623-630
8Goodbum SF, Yates JR, Raggatt PR, et al. Second- trimester maternal serum screening using alpha - fetoprotein, human chorionic gonadotropin and unconjugated oestriol: experience of a regional programme. Prenat Diagn, 1994, 14:391-402
9Wald NJ, Cuckle HS, Densen JW, et al. Maternal serum screening for Down's syndrome in early pregnancy. BMJ, 1988, 297:883 - 887
10Chao AS, Chung CL, Wu CD, et al. Second trimester maternal serum screening using alpha fetoprotein, free beta human chorionic gonadotropin and maternal age specific risk: result of chromosomal abnormalities detected in screen positive for Down syndrome in an Asian population. Acta Obstet Gynecol Scand, 1999, 78(5): 393 - 397
7Clementi M,Bianca S,Tenconi R. Re: "parity and the risk of Down' s syndrome" [J].Am J Epidemiol,2004,160(6):609-610.
8Stoeva SI,Lee JS,Smith J E,et al. Multiplexed detection of protein caneer markers with biobarcoded nanopartide probes [J]. J Am Chen Soe,2006,128(26):8378-8379.
9Cuckle H,Benn P, Wright D.Down syndrome screening in the first and/or second trimester :Model predicted performance using meta- analysis parameters [J]. Semin perinatol,2005,29(4):252-257.
10Benn P;Weight D;Cuckle H.Practical strategies in contingent sequential screening for Down syndrome,2005.