D'Alton M E, Dudley D K
Department of Obstetrics and Gynecology, Ottawa Civic Hospital, Ontario, Canada.
Am J Obstet Gynecol. 1989 Mar;160(3):557-61. doi: 10.1016/s0002-9378(89)80025-0.
In a prospective study of 69 consecutive twin gestations, chorionicity was assessed ultrasonographically, by the new technique of counting the number of layers visualized in the dividing membrane. For purposes of the study the antenatal categorization of chorionic type was based only on the number of layers observed. The pregnancy was classified as monochorionic when only two layers were identified and as dichorionic if three or four layers were seen. Confirmation of chorionic type was obtained after delivery by histopathologic examination of the placenta. The ultrasonographic technique used correctly determined chorionicity in 68 of 69 twin pregnancies. The predictive accuracy was 100% for 51 pregnancies designated by ultrasonography as dichorionic and 94.4% for 18 pregnancies considered to be monochorionic. These results suggest that counting the number of layers seen in fetal membranes by ultrasonography examination is an accurate way of determining chorionicity in twin gestation.
在一项对69例连续双胎妊娠的前瞻性研究中，通过超声检查采用计数分隔膜中可见层数的新技术来评估绒毛膜性。为了本研究的目的，绒毛膜类型的产前分类仅基于观察到的层数。当仅识别出两层时，妊娠被分类为单绒毛膜；如果看到三层或四层，则分类为双绒毛膜。分娩后通过胎盘组织病理学检查获得绒毛膜类型的确认。所使用的超声技术在69例双胎妊娠中的68例中正确确定了绒毛膜性。对于超声检查指定为双绒毛膜的51例妊娠，预测准确率为100%；对于被认为是单绒毛膜的18例妊娠，预测准确率为94.4%。这些结果表明，通过超声检查计数胎膜中可见的层数是确定双胎妊娠绒毛膜性的准确方法。
