5Timor-Tritsch I E,Masch R J,Goldstein S R,et al.Transvaginal ultrasound-assisted gynecologic surgery:evaluation of a new device to improve safety of intrauterine surgery[J].Am J Obstet Gynecol,2003,189(4):1074. 被引量：1
6Lohr P A,Reeves M F,Greinin M D.A comparison of transabdominal and transvaginal ultrasonography for determination of gestational age and clinical outcoms in wemen undergoing early medical abortion[J].contraception,2010,81(3):240. 被引量：1
9[1]Ho PC, Liang ST, Tang GWK, et al. Pro-operative cervical dilatation in termination of first trimester pregnancies using 16,16-methy-trans-GPE1 methy1 ester vaginal pessaries. Contraception, 1983,27:339-346. 被引量：1
10[2]Singh K, Fong YF. Preparation of the cervix for surgical termination of pregnancy in the first trimester. Hum Reprod Update, 2000, 6: 442-448. 被引量：1
