Hertzberg B S, Kurtz A B, Choi H Y, Kaczmarczyk J M, Warren W, Wapner R J, Needleman L, Baltarowich O H, Pasto M E, Rifkin M D
AJR Am J Roentgenol. 1987 Jan;148(1):151-3. doi: 10.2214/ajr.148.1.151.
A retrospective study of 55 twin pregnancies was performed to determine the role of sonography in distinguishing between dichorionic and monochorionic diamniotic gestations solely by evaluating the thickness of the membrane between the fetuses. The presence of a thick dividing membrane indicated a dichorionic diamniotic gestation in 38 (90%) of 42 cases in which it was identified. Inability to identify a membrane between dichorionic diamniotic twins occurred most commonly during the third trimester. A thin membrane indicated monochorionic diamniotic twinning and was seen in three (25%) of 12 cases. Membrane thickness was indeterminate in one case. Therefore, on the basis of the thickness of the dividing membrane imaged by sonography, dichorionic diamniotic gestations can be distinguished from monochorionic diamniotic gestations. Inability to show a separating membrane by sonography, however, can occur with any form of twin gestation, particularly in the third trimester. Membrane thickness should be used in conjunction with other sonographic criteria to predict the amnionicity and chorionicity of twin gestations.
对55例双胎妊娠进行了一项回顾性研究，以确定超声检查仅通过评估胎儿间胎膜厚度在鉴别双绒毛膜双羊膜囊妊娠和单绒毛膜双羊膜囊妊娠中的作用。在42例识别出厚分隔膜的病例中，有38例（90%）厚分隔膜提示双绒毛膜双羊膜囊妊娠。双绒毛膜双羊膜囊双胎之间无法识别胎膜的情况最常发生在妊娠晚期。薄胎膜提示单绒毛膜双羊膜囊双胎，在12例中有3例（25%）可见。1例胎膜厚度无法确定。因此，根据超声检查所显示的分隔膜厚度，双绒毛膜双羊膜囊妊娠可与单绒毛膜双羊膜囊妊娠相鉴别。然而，超声检查无法显示分隔膜的情况可发生于任何形式的双胎妊娠，尤其是在妊娠晚期。胎膜厚度应与其他超声检查标准结合使用，以预测双胎妊娠的羊膜性和绒毛膜性。
