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 VOLUME Vol.05 Issue08 2025 

PAGE NO. 13-16 

DOI 10.37547/ajbspi/Volume05Issue08-03 

 
 
 
 

Rarely Encountered Umbilical Cord Pathologies 

(Literature Review) 
 

Tojiyeva Nigina Iskandarovna 

Assistant, department of Obstetrics and gynecology #1, Samarkand State Medical University, Uzbekistan 

 

 

Received: 17 June 2025; Accepted: 13 July 2025; Published: 15 August 2025 

 

Abstract: This review systematizes current knowledge about umbilical cord abnormalities (UCAs) — a 
heterogeneous group of anomalies including length abnormalities, number of vessels, attachments, nodes, cysts, 
and vascular malformations. Based on the analysis of scientific literature (2000–2024), the epidemiological data 
are presented: UCAs occur in 15–35% of pregnancies, with single umbilical artery (SUA) — in 0.5–5%, velmen 
insertion — up to 50% in monochorionic twins, and true nodes — in 0.3–1.2%. The review details complications: 
fetal growth restriction (FGR), chronic and acute hypoxia, antenatal death, risks during childbirth (vascular rupture 
in vasa praevia, asphyxia). Particular attention is paid to early diagnostic methods: ultrasound with Doppler (blood 
flow assessment, EAP), color Doppler mapping (Velmen attachment), 3D/4D ultrasound in STIC mode (nodes, 
spatial anomalies), CTG monitoring. Differentiated management tactics are substantiated: from dynamic 
observation at low risk to planned cesarean section for vasa praevia or IUGR. It is emphasized that timely 
diagnostics and an individualized approach reduce perinatal mortality and improve outcomes. 

 

Keywords: Umbilical cord cysts; varicose umbilical veins (varix); Pregnancy complications; Perinatal outcomes; 
Fetal growth restriction (FGR); Cord structure pathology. 

 

Introduction: In addition to relatively common 
anomalies (entanglement, EAP), there are rare 
umbilical cord pathologies that pose significant 
diagnostic and clinical challenges due to their low 
incidence, insufficient study, and potentially 
catastrophic consequences for the fetus. These include 
umbilical cord hypoplasia, varicose umbilical veins 
(varix), and true umbilical cord cysts. Their prevalence 
does not exceed 1-3%, which complicates the 
accumulation of evidence [1, 2].  

The objective of the review is to systematize data on 
epidemiology, classification (ICD-10/ICD-11), 
etiopathogenesis, impact on pregnancy and fetus, 
diagnostic methods, and principles of patient 
management with these rare pathologies based on an 
analysis of modern literature (2014-2024). 

METHODS 

A systematic search was conducted in PubMed, 
MEDLINE, Scopus, Cochrane Library, and eLibrary 
databases for the period 2014–2024. Key words: "thin 
umbilical cord", "umbilical cord hypoplasia", "umbilical 

vein varix", "fetal intra-abdominal umbilical vein varix", 
"umbilical cord cyst", "rare umbilical cord 
abnormalities", "prenatal diagnosis", "pregnancy 
outcome", "fetal complications", "ICD-10", "ICD-11". 
Original studies (prospective and retrospective cohort 
studies, case series), systematic reviews, meta-
analyses, and clinical guidelines were included. 
Publications in languages other than English and 
Russian, without an abstract, and articles with a low 
level of evidence (reports of single cases without 
literature analysis, expert opinions without data) were 
excluded. 

RESULTS 

Rare umbilical cord pathologies are characterized by 
low prevalence. Hypoplasia of the umbilical cord 
(diameter < 8–10 mm in the second trimester or < 5–8 
percentile) occurs in less than 1% of pregnancies and is 
coded in ICD-10 as O69.8, and in ICD-11 as JA20.2 
[1,3,4]. Umbilical vein varices (UVV) - focal enlargement 
of the vein > 9 mm or > 50% of adjacent areas - is 
diagnosed in 0.4–1.1% of cases (ICD-10: O69.8/Q27.8; 
ICD-11: JA20.2/LA8F) [2,5,6]. True umbilical cord cysts 

 

https://doi.org/10.37547/ajbspi/Volume05Issue08-03
https://doi.org/10.37547/ajbspi/Volume05Issue08-03
https://doi.org/10.37547/ajbspi/Volume05Issue08-03
https://doi.org/10.37547/ajbspi/Volume05Issue08-03


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American Journal of Applied Science and Technology (ISSN: 2771-2745) 
 

 

(anechoic formations of embryonic origin) are detected 
in 0.1–0.5% of cases (ICD-10: O69.8/Q79.8; ICD-11: 
JA20.2/LB11) [7,8]. Hypoplasia is associated with 
Wharton's jelly deficiency caused by impaired 
angiogenesis (decreased VEGF, PlGF) and mesenchymal 
differentiation. Key risk factors: maternal smoking, 
thrombophilia, history of IUGR [1,3,4]. UVV develops 
due to weakness of the venous wall, local elastin 
defects, increased venous pressure (fetal heart failure, 
arteriovenous shunts) or portal system thrombosis. 
Pathogenesis includes turbulent blood flow → 
endothelial damage → risk of thrombosis/rupture 
[2,5,6]. True cysts are formed due to the persistence of 
embryonic structures: the allantois (urogynectic cysts) 
or the omphalo-mesenteric duct [7,8]. 

Perinatal risks of rare umbilical cord pathologies are 
characterized by significant variability. In case of 
umbilical cord hypoplasia, there is a 3.5–5-fold increase 
in the risk of fetal growth restriction (FGR) (relative risk 
[RR] 3.5–5.0), which correlates with chronic hypoxia, 
manifested by an increase in the resistance index (RI) in 
the umbilical artery by 40% compared to the norm, as 
well as an increase in the risk of antenatal fetal death 
by 2–3 times [1,3,4]. Varicose umbilical vein (UVV) is 
associated with antenatal death in 8–15% of cases, 
mainly due to thrombosis, while the risk of intrapartum 
rupture of the varicose node reaches 4–7% with fetal 
mortality exceeding 90% [2,5,6,13]. This pathology is 
also associated with the development of IUGR in 24% 
of fetuses and a combination with congenital 
anomalies in 18-30% of cases [5,6]. True umbilical cord 
cysts diagnosed in the first trimester demonstrate an 
association with chromosomal abnormalities (mainly 
trisomy 18) in 15-20% of cases, while large cysts (>40-
50 mm) cause vascular compression leading to IUGR in 
12-18% of fetuses [7,8,14]. 

Diagnostic algorithms are based on a comprehensive 
ultrasound examination. The key criteria for hypoplasia 
are a decrease in the umbilical cord diameter to less 
than 8 mm in the second trimester, a decrease in the 
volume of Wharton's jelly and pathological Doppler 
parameters (RI>0.8 in the umbilical artery, reverse 
blood flow in the venous duct), which are predictors of 
IUGR [1,4]. UVV diagnostics is based on the detection 
of vein dilation greater than 9 mm in diameter, 
registration of turbulent flow during color Doppler 
mapping (CDM) and an increase in peak systolic 
velocity (PSV) greater than 40 cm/s, which is associated 
with a high risk of thrombus formation [2,5,6]. True 

cysts are identified as anechoic formations without 
internal blood flow during CDM, while the use of three-
dimensional ultrasound (3D-ultrasound) allows them to 
be differentiated from false cysts due to visualization of 
the epithelial lining [7,8]. As additional methods, fetal 
magnetic resonance imaging (MRI) demonstrates high 
sensitivity (92%) in assessing portal system thrombosis 
in UVV and vascular compression by large cysts (>30 
mm) [2,8], and invasive prenatal diagnostics 
(karyotyping/chromosomal microarray analysis) is 
recommended for UVV and first trimester cysts due to 
the frequency of aneuploidies reaching 18% [5,7]. 

Modern scientific developments (2020–2024) are 
aimed at improving prognosis and diagnostics. A 
multiparameter risk index for UVV has been developed, 
including vein diameter, PSV, and the presence of a 
thrombus, with an area under the ROC curve (AUC) of 
0.89 [6], and for the early detection of complications in 
hypoplasia, a prognostic significance of a decrease in 
the umbilical cord diameter to less than 2.5 mm in the 
first trimester, associated with the development of 
IUGR in 80% of cases, has been established [3,4]. 
Technological innovations include the use of 3D power 
doppler for quantitative assessment of umbilical cord 
vascularization, where a decrease in the vascularization 
index correlates with the severity of IUGR in hypoplasia 
(correlation coefficient r = 0.72) [4], as well as the use 
of the STIC mode in 4D ultrasound, which increases the 
accuracy of diagnosing vascular compression by cysts 
by 35% [8]. In the field of biomarkers, a promising 
direction is the determination of the sFlt-1/PIGF ratio 
(>38) in UVV as an indicator of endothelial dysfunction 
[6], and the detection of elevated levels of alpha-
fetoprotein (AFP) and beta-subunit of human chorionic 
gonadotropin (β-hCG) in amniotic fluid in cysts 
associated with trisomy 18 [7]. 

Differentiated tactics are based on the pathogenetic 
features of each nosology. In case of hypoplasia, 
intensive monitoring is required (Dopplerometry 2 
times a week, CTG from 28 weeks), and the 
development of blood flow disorders requires early 
delivery by cesarean section at 34–37 weeks [1,4]. 
Management of UVV includes planned operative 
delivery at 34–36 weeks to prevent thrombosis and 
rupture, supplemented by daily CTG monitoring and 
weekly Doppler [2,5,6]. For large true cysts (>50 mm), 
delivery at 36–38 weeks is recommended if there are 
signs of vascular compression or IUGR [7,8]. 

 

 

 



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Table 1 

Principles of management 

Pathology Monitoring Delivery 

Hypoplasia Ultrasound + Doppler/CTG 2 times a week; 

hospitalization for IUGR 

Planned CS at 34–37 weeks with 

impaired blood flow 

UVV Ultrasound + Doppler 2 times a week; CTG daily; 

hospitalization 

Planned CS at 34–36 weeks (standard) 

cysts > 50 

мм 

Growth monitoring Doppler (ultrasound 1 time/2 

weeks);  

CS at 36–38 weeks with vascular 

compression 

> These approaches are based on cohort studies and 
systematic reviews of the last decade, emphasizing the 
need for personalized risk management [1–8,14]. 

CONCLUSION 

Rare umbilical cord pathologies (hypoplasia, umbilical 
vein varices, true cysts), although occurring in less than 
1-3% of cases, are significant causes of perinatal 
morbidity and mortality. Their timely prenatal 
diagnosis using modern ultrasound technologies 
(including Doppler and 3D/4D) and fetal MRI is critically 
important. The pathogenesis of many of these 
conditions requires further study. Pregnancy 
management should be based on a thorough 
assessment of fetal risks using all available diagnostic 
tools. In cases of UVV and progressive hypoplasia with 
IUGR, planned early delivery by cesarean section is 
indicated. Further studies should be aimed at 
identifying biomarkers, clarifying the genetic basis and 
developing standardized protocols for monitoring and 
delivery to improve perinatal outcomes. 

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