Pitfalls in assessing chorioamnionicity: novel observations and literature review
Publication in refereed journal


摘要Accurate diagnosis of chorioamnionicity in multiple pregnancies is the key to appropriate clinical management of multiple gestation. Although prenatal ultrasound assessment of chorioamnionicity is well established and highly accurate if performed in early pregnancy, exceptions and artifacts arise from anatomic variations in multiple pregnancies and unusual sonographic features do exist. We have summarized our own experiences and reports from the literature on these pitfalls as follows: (1) discordant fetal sex in monochorionic pregnancies due to sex chromosome abnormalities, genital malformation in 1 fetus, or dizygotic twins forming a monochorionic placenta; (2) separate placental masses in monochorionic pregnancies due to bipartite placenta; (3) false-negative and false-positive λ sign can arise for various reasons, and in partial monochorionic/dichorionic placentas both T and λ sign may co-exist; (4) intrauterine synechia appearing as a thick and echogenic intrauterine septum may lead to erroneous diagnosis of dichorionic twins; and (5) errors in ascertaining amnionicity by the visualization of thin intertwin amniotic membranes and the number of yolk sacs. The ultrasound techniques to reduce inaccuracy in prenatal determination of chorioamnionicity and the use of single nucleotide polymorphisms based on noninvasive prenatal test to determine zygosity are also reviewed.
著者Lu J, Cheng YKY, Ting YH, Law KM, Leung TY
期刊名稱American Journal of Obstetrics and Gynecology
頁次242 - 254
關鍵詞amnionicity, chorionicity, discordant sex, dizygotic, intertwin membrane, pitfall, separate placentas, twin peak sign, ultrasound

上次更新時間 2020-28-06 於 01:53