Hill L M, Chenevey P, Hecker J, Martin J G
Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Pennsylvania, USA.
J Clin Ultrasound. 1996 Jul-Aug;24(6):305-8. doi: 10.1002/(SICI)1097-0096(199607/08)24:6<305::AID-JCU4>3.0.CO;2-M.
To determine the reliability of first trimester sonography in the detection of twin chorionicity and amnionicity.
Sets of twins (179) were evaluated sonographically in the first trimester. Chorionicity was determined by identifying the number of gestational sacs. The presence or absence of an amnion about each embryo/fetus was also recorded. The placentas for each case were evaluated to determine chorionicity and amnionicity.
Of the 179 twin pairs, 158 were dichorionic/diamniotic; 19 were monochorionic/diamniotic, and two pairs were monochorionic/monoamniotic. Chorionicity and amnionicity were correctly determined in each case.
The chorionicity of twin pregnancies can be determined from the time that the gestational sacs are visualized within the uterus. Transvaginal sonography can reliably determine the amnionicity of monochorionic twin pregnancies after 7 weeks, menstrual age.
确定孕早期超声检查在检测双胎绒毛膜性和羊膜性方面的可靠性。
对179例双胎妊娠在孕早期进行超声评估。通过识别妊娠囊数量来确定绒毛膜性。同时记录每个胚胎/胎儿周围羊膜的有无情况。对每例病例的胎盘进行评估以确定绒毛膜性和羊膜性。
179对双胎中，158对为双绒毛膜/双羊膜囊；19对为单绒毛膜/双羊膜囊，2对为单绒毛膜/单羊膜囊。每例病例的绒毛膜性和羊膜性均被正确判定。
从子宫内可见妊娠囊时起即可确定双胎妊娠的绒毛膜性。经阴道超声检查在月经龄7周后能够可靠地确定单绒毛膜双胎妊娠的羊膜性。
