American Journal Of Biomedical Science & Pharmaceutical Innovation
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VOLUME
Vol.05 Issue08 2025
PAGE NO.
13-16
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
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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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American Journal of Applied Science and Technology (ISSN: 2771-2745)
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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