7Thuesen LL, Diness BR, Langhoff - Roos J. Pre - pregnancy transabdomihal cerclage[J]. Acta Obstet Gynecol Scand,2009,88 (4) :483.
8Poggi SH, Vyas N, Pczzullo JC, et al. Therapeutic cerclage may be more efficacious in women who develop cervical insufficiency after a term delivery[J]. Am J Obstet Gynecol, 2009, 200 (1) : 68.
10Berghella V, Odibo AO, To MS, et al. Cerclage for short cervix on uhrasonography: meta- analysis of trials using individual patient level data [J]. Obstet Gynecol, 2005, 106 (1) : 181.
4Macdonald R,Smith P,Vyas S.Cervical incompetence:the use of transvaginal sonography to provide an objective diagnosis.Ultrasound Obstet Gynecol,2001,18(3):211-6.
5Brook I,Feingold M,Schwart ZA,et al.Ultrasonography in the diagnosis of cervical incompetence in pregnancy:a new diagnosis approach.Br J Obstet Gynecol,1981,88(6):640-3.
6Podobnik M,Bulic M,Smiljanic N,et al.Ultrasonography in the detection of cervical incompetency.J Clin Ultrasound,1988,16(6):383-91.
7Iams JD,Paraskos J,Landon MB,et al.Cervical sonography in preterm labor.Obstel Bvnecol,1994,84(1):40-6.
