6Hahnemann N. Possibility of culturing fetal cells at early stages of pregnancy[J]. Clin Genet , 1972,3 (4) : 286-293.
7Papp C, Beke A, Mezei G, et al. Chorionic villus sam piing a 15 year experience [J]. Fetal Diagn Ther, 2002,17(4) :218-227.
8Department of Obster and Gynecol. Tietong Hosp of Anshan Iron and Steel Co, Anshan, China. Fetal sex prediction by sex chromatin of chorinic villi cells during early pregnancy [J].Chin MedJ,1975,1(2) :117-126.
9Simoni G,Brambiti B,Denestno C, et al. Efficient direct chromosome analyses and enzyme determination from chorinic villi samples in the first trimester of pregnancy [J]. Hum Genet, 1983, 63(4):349-357.
10Simoni G, Brambiti B, Denestno C, et al. Diagnosis application of first trimester trophoblast sampling in 100 pregnancy[J]. Hum Genet,1984, 66 (22-23) :252-259.
