[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-417361-105":3,"detail-sidebar-cat-0-en-105":81,"doc-detail-417361-en":130},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","potentially-dangerous-incidental-finding-on-obstetric-ultrasound-a-true-umbilical-cord-knot-imaging-for-residents-answer","Potentially Dangerous Incidental Finding on Obstetric Ultrasound - A True Umbilical Cord Knot - Imaging for Residents - Answer","","A 28-year-old woman at 37 weeks underwent antenatal ultrasound for amniotic fluid assessment and an incidental abnormality was identified. The transverse ultrasound appearance of a umbilical cord segment surrounded by another loop corresponded to the “hanging noose sign,” confirming a true umbilical cord knot (TUCK). Fetal Doppler and cardiotocography were reassuring, and delivery proceeded uneventfully with a healthy newborn. The article reviews TUCK prevalence, risk factors, and key distinctions between true and false knots, emphasizing monitoring and expectant management when fetal compromise is absent.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/healthcare/","Healthcare",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/potentially-dangerous-incidental-finding-on-obstetric-ultrasound-a-true-umbilical-cord-knot-imaging-for-residents-answer/417361/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/potentially-dangerous-incidental-finding-on-obstetric-ultrasound-a-true-umbilical-cord-knot-imaging-for-residents-answer/417361.png","ImageObject",300,407,{"name":42,"@type":43},"acoobca","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-11-01","2026-09-28",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",10,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"What imaging sign on obstetric ultrasound confirms a true umbilical cord knot (TUCK)?","Question",{"text":63,"@type":64},"A transverse ultrasound view showing a cord segment surrounded by another loop corresponds to the “hanging noose sign,” confirming TUCK.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"How do Doppler and cardiotocography findings relate to TUCK risk?",{"text":68,"@type":64},"In this case, fetal Doppler and cardiotocography were normal, supporting expectant management. TUCK becomes concerning if it leads to abnormal fetal heart rate patterns or other evidence of fetal compromise.",{"name":70,"@type":61,"acceptedAnswer":71},"What differentiates a true umbilical cord knot from a false knot on ultrasound?",{"text":72,"@type":64},"True knots show an encircling configuration on grayscale and specific Doppler features such as the hanging noose sign. False knots result from vessel twisting or redundancy and do not demonstrate an actual encircling knot.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},417361,1790949056,{"code":4,"msg":82,"data":83},"success",[84,88,92,96,101,106,110,115,120,123,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":97,"doc_module":4,"doc_module_name":25,"category_name":98,"show_sort_weight":99,"slug":100},5,"Comic",60,"comic",{"id":102,"doc_module":4,"doc_module_name":25,"category_name":103,"show_sort_weight":104,"slug":105},6,"Technology",50,"technology",{"id":107,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":108,"slug":109},7,40,"healthcare",{"id":111,"doc_module":4,"doc_module_name":25,"category_name":112,"show_sort_weight":113,"slug":114},8,"Research & Report",30,"research-report",{"id":116,"doc_module":4,"doc_module_name":25,"category_name":117,"show_sort_weight":118,"slug":119},9,"Religion & Spirituality",20,"religion-spirituality",{"id":118,"doc_module":4,"doc_module_name":25,"category_name":121,"show_sort_weight":118,"slug":122},"World Cup","world-cup",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":55,"slug":125},"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":97,"slug":129},19,"General","general",{"code":4,"msg":82,"data":131},{"doc_id":79,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":107,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":26,"language":139,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":12,"update_tm":143,"read_time":97,"preview_page_count":4},3985747870733,"https://ap-avatar.wpscdn.com/davatar_a8503ba1806abce46bf441b54a3ca4cd","| Imaging for Residents – Answer |\n| --- |\n|  |\n\nPotentially Dangerous Incidental Finding on Obstetric Ultrasound – A True Umbilical Cord Knot  \nVenkatraman Indiran*  \nDepartment of Radiodiagnosis, Sree Balaji Medical College and Hospital, Chennai, Tamil Nadu, India  \nSection 2 – AnSwer cASe  \nA 28‑year‑old female with no comorbidities came for an antenatal ultrasound scan at 37 weeks of pregnancy for the assessment of amniotic fluid. The fetal biometry was appropriate for age. Amniotic fluid index was normal (~ 10–11 cm) . Figure 1 shows an incidental finding. What is the imaging sign shown and diagnosis?  \ninterpretAtion  \nTransverse section of a segment of the umbilical cord surrounded by another loop of umbilical cord seen on ultrasound inpatients with true umbilical cord knots (TUCKs) is known asthe “hanging noose sign” [Figure 1] .[1] “Hanging noose sign”confirmed the diagnosis of “TUCK.” Her fetal Doppler and cardiotocography findings were normal. Cardiotocography showed a fetal heart rate of approximately 140 beats per minute  \nFigure 1: Greyscale ultrasound (a) and color Doppler (b) transverse section in a patient with true umbilical cord knot showing a segment of the umbilical cord (black arrows) surrounded by another loop of umbilical cord (white arrows), representing the hanging noose sign. Color Doppler (b) image showing the knot (white arrows) surrounding the inner loop of the cord (black arrow)  \nReceived: 04-02-2025 Revised: 27-02-2025 Accepted: 10-03-2025 Available Online: 02-09-2025  \n\n| Access this article online |  |\n| --- | --- |\n| Quick Response Code:\u003Cbr>| Website:\u003Cbr>[https://journals.lww.com/jmut](https://journals.lww.com/jmut) |\n|  | DOI:\u003Cbr>10.4103/jmu.JMU-D-25-00021 |\n\nwith a category 1 tracing. Cerebroplacental ratio, umbilical artery systolic/diastolic ratio, pulsatility index, and resistance index were normal. A couple of days later, this patient had an uneventful vaginal delivery of a healthy 2.8 kg male baby with Apgar score (8/10). Umbilical cord measured~60 cm in length and showed a true knot ~20 cm before placental insertion.  \nDiScuSSion  \nTUCKs have a prevalence of about 1%–2% .[2] Predisposing factors for TUCK include long cord, small fetus, polyhydramnios, monoamniotic twins, male babies, grand multiparity, and amniocentesis. [3,4] It is also important to differentiate true and false umbilical cord knots. TUCKs are actual knots in the umbilical cord formed during pregnancy. False umbilical cord knots are due to bulge in umbilical cord due to twisting of the vein around the arteries or due to excessive Wharton’s jelly or just a varicosity or redundancy of an umbilical vein within the cord substance, but none of these findings show an actual knot in the cord.[4,5] Distinguishing true and false umbilical cord knots on ultrasound is important [Table 1] . [6] TUCK usually manifests between 9 and 12 weeks of pregnancy, when sufficient liquor and vigorous fetal movements allow the fetus to pass through a cord loop, but problems usually arise later in pregnancy. Most TUCKs are loose and are detected only after delivery of the baby.[2] Adverse pregnancy and labor outcomes in TUCK include small for gestational age fetus, a lowApgar score at birth, fetal hypoxia, and fetal death (stillbirth) .[7] The presence of an umbilical cord knot alone is not an indication for delivery unless associated with fetal compromise which maybe manifest as an abnormal fetal heart rate pattern or elevated umbilical artery systolic–  \nAddress for correspondence: Dr. Venkatraman Indiran,  \nDepartment of Radiodiagnosis, Sree Balaji Medical College and Hospital, 7 Works Road, Chromepet, Chennai ‑ 600 044, Tamil Nadu, India.  \nE‑mail: [ivraman31@gmail.com](ivraman31@gmail.com)  \nThis is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License (CC BY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work canno","cbCaigHbA8rUgxIm","https://ap.wps.com/l/cbCaigHbA8rUgxIm","pdf",450614,"English","# Imaging sign and diagnosis\n## Hanging noose sign and TUCK confirmation\n# Clinical course and delivery outcome\n# Discussion\n## Prevalence and risk factors\n## True vs false umbilical cord knots\n## Management and outcomes","[{\"question\":\"What imaging sign on obstetric ultrasound confirms a true umbilical cord knot (TUCK)?\",\"answer\":\"A transverse ultrasound view showing a cord segment surrounded by another loop corresponds to the “hanging noose sign,” confirming TUCK.\"},{\"question\":\"How do Doppler and cardiotocography findings relate to TUCK risk?\",\"answer\":\"In this case, fetal Doppler and cardiotocography were normal, supporting expectant management. TUCK becomes concerning if it leads to abnormal fetal heart rate patterns or other evidence of fetal compromise.\"},{\"question\":\"What differentiates a true umbilical cord knot from a false knot on ultrasound?\",\"answer\":\"True knots show an encircling configuration on grayscale and specific Doppler features such as the hanging noose sign. False knots result from vessel twisting or redundancy and do not demonstrate an actual encircling knot.\"}]","Potentially Dangerous Incidental Finding on Obstetric Ultrasound - A True Umbilical Cord Knot - Imaging for Residents - Answer | PDF",1790608963]