5Kerenyi TD, Chitkara U. Selective birth in twin pregnancy with dicordancy for Down' s syndrome[ J]. N Engl J Med, 1981, 304(25) :1525-1527.
6Massad ZC, Gill I, Fakih MH, et al. Very early transvaginal embryo aspiration: a safe and effective method formuhifetal pregnancy reduction [ J ]. Fertil Steril, 2000, 74 : S159.
7Lee J, Ku S, Jee B, et al. Outcomes of multifetal pregnancy reduction : early transvaginal non - KCl method is the bestway[ J]. Fertil Steril, 2005, 84 : S353.
8Wimalasundera RC, Trew G, Fisk NM. Reducing the incidence oftwins and triplets. Best Pract Res Clin Obstet Gynaecol, 2003, 17(2) : 309.
9Stone J, Eddleman K, Lynch L, et al. A single center experience with 1 000 consecutive cases of muhifetal pregnancy reduction. Am J Obstet Gynecol, 2002,187(5): 1 163.
10Sebire NJ,Snijders R J, Santiago C,et al. Management of twin pregnancies with fetal trisomies, Br J Obstet Gynecol, 1997,104 ( 2 ) : 220.