Spontaneous echo contrast and decreased umbilical vein blood flow may predict thrombus formation in fetal intra-abdominal umbilical vein varix

PURPOSE

Fetal intra-abdominal umbilical vein varix (FIUVV) can cause thrombosis, fetal growth restriction (FGR), and intrauterine fetal death (IUFD). However, its management and evaluation to avoid fetal risks have not been elucidated. The aim of this study was to develop a novel method to evaluate fetal risks, including FGR and fetal dysfunction via frequent ultrasound examinations.

METHODS

A 28-year-old pregnant woman was diagnosed with FIUVV via ultrasound at 26 weeks of gestation and admitted to our hospital. Ultrasound examinations were performed two to three times weekly to evaluate size and shape of the FIUVV and umbilical vein blood flow at the inflow and outflow sites of the FIUVV.

RESULTS

The outflow site of the FIUVV was constricted and collapsed, and the blood flow velocity at the inflow site of the FIUVV was decreased. At 32 weeks of gestation, spontaneous echo contrast (SEC), which indicates increased echogenicity, appeared. At 35 weeks of gestation, the patient noticed decreased fetal movement, and CTG showed non-reassuring fetal status. SEC in the FIUVV was remarkable. Fetal movement could not be confirmed at ultrasound. Cesarean section was performed and a 1,854-g healthy infant was delivered with an umbilical cord arterial pH of 7.266.

CONCLUSION

The echographic changes, such as decreased umbilical vein blood flow and SEC, in FIUVV observed in this case could indicate thrombus formation, which can lead to fetal dysfunction. Frequent ultrasound examinations can help determine the timing of delivery and improve the neonatal prognosis.

Isolated fetal umbilical vein varix and the association with intrauterine fetal death and fetal growth restriction: A systematic review, meta-analysis, and nested retrospective cohort study

OBJECTIVES

To assess the risk of intrauterine fetal death (IUFD) and fetal growth restriction (FGR) in fetuses with an isolated fetal intra-abdominal umbilical vein varix (i-FIUVV).

METHODS

A retrospective cohort study combined with a systematic review and meta-analysis of the literature was performed. In the retrospective cohort study, all singleton fetuses with an i-FIUVV in the fetal medicine units of the Amsterdam UMC (between 2007 and 2023) were analyzed. The primary outcome measures were IUFD and FGR. The sample proportions of IUFD and FGR were depicted as risk percentages. The IUFD proportion was compared to the regional reference population and the FGR proportion was compared to the reported proportions in Europe. The secondary outcome measures were gestational age at diagnosis, initial and maximal FIUVV diameter, fetal monitoring in pregnancy, turbulent flow in the varix, thrombus formation in the varix, induction of labor, gestational age at birth, and birthweight centile. The proportion of fetuses with a birthweight below the 10th centile was compared with that of the regional reference population. The systematic review included all cases from eligible literature published between 2007 and 2023 supplemented by the data of our retrospective cohort study. In the systematic review and meta-analysis, the pooled proportions of IUFD and FGR were assessed in fetuses with i-FIUVV.

RESULTS

The retrospective cohort included 43 singletons with an i-FIUVV. The IUFD risk was 0% [Confidence Interval, CI: 0%-8.2%], which did not differ significantly from 0.3% in the reference population, p = 1.0. The risk of FGR was 16.3% [CI: 6.8%-30.7%] in the studied population, which is higher than the reported incidence of FGR in Europe ranging from 5%-10%. The proportion of fetuses with birthweights below the 10th centile was higher in our cohort compared with the reference population (23.3 vs. 9.9%, p < 0.01). The systematic review included 12 articles, three abstracts, and our current cohort. In total, 513 cases with an i-FIUVV were included. The pooled risk was 0.4% [CI: 0.1%-1.7%] for IUFD and 5.2% [CI: 1.1%-21.3%] for FGR. The mean gestational age at birth did not exceed 39 weeks in neither the cohort (38.7 weeks) nor the pooled literature (37.6 weeks).

CONCLUSION

An i-FIUVV in singletons is not associated with an increased IUFD risk up to 39 weeks of gestation but is possibly associated with FGR. The incidence of FGR in our cohort was higher than in the pooled literature (16.3% vs. 5%) but FGR definitions in the included studies varied. The proportion of birthweights below the 10th percentile in our cohort was significantly higher than in the reference group. Thus, based on these findings, we suggest conducting sonographic growth assessments while simultaneously assessing the i-FIUVV. No further monitoring and follow-up are indicated up to 39 weeks of gestation. After 39 weeks of gestation, data on fetuses with i-FIUVV and their outcomes are lacking.

Foetal death due to extensive extra-abdominal umbilical vein Varix with umbilical vein thrombosis: a case report

BACKGROUND

Foetal anaemia and umbilical vein thrombosis are rare pregnancy complications that can increase the risk of perinatal adverse events, which, in severe cases, can lead to foetal death. During pregnancy, umbilical vein varix (UVV) commonly occurs in the intra-abdominal part of the umbilical vein and is associated with an increased risk of foetal anaemia and umbilical vein thrombosis. However, UVV occurring in the extra-abdominal part of the umbilical vein is rare, especially when accompanied by thrombosis. In this case report, we describe a rare case of an extensive extra-abdominal umbilical vein varix (EAUVV), which ultimately resulted in foetal death due to umbilical vein thrombosis.

CASE PRESENTATION

In this report, we describe a rare case of an extensive EAUVV that was discovered at 25 weeks and 3 days of gestation. During the examination, there were no abnormalities in foetal haemodynamics. The estimated weight of the foetus was only 709 g. In addition to refusing to be hospitalized, the patient refused close monitoring of the foetus. As a result, we were limited to choosing an expectant therapy. The foetus died 2 weeks after diagnosis and was confirmed to have EAUVV with thrombosis after the induction of labour.

CONCLUSION

In the case of EAUVV, lesions are extremely rare, and it is very easy for thrombosis to form, which may result in the death of the child. When determining the next step in the treatment of the condition, the degree of UVV, possible complications, gestational age, foetal haemodynamics, and other relevant factors are strongly connected to the clinical therapy decision, and these factors should be considered comprehensively when making a clinical decision. We recommend close monitoring with hospital admission (to facilities capable of handling extremely preterm foetuses) after variability in delivery for worsening haemodynamic status.

Current Perspectives of Prenatal Sonography of Umbilical Cord Morphology

The umbilical cord constitutes a continuation of the fetal cardiovascular system anatomically bridging between the placenta and the fetus. This structure, critical in human development, enables mobility of the developing fetus within the gestational sac in contrast to the placenta, which is anchored to the uterine wall. The umbilical cord is protected by unique, robust anatomical features, which include: length of the umbilical cord, Wharton’s jelly, two umbilical arteries, coiling, and suspension in amniotic fluid. These features all contribute to protect and buffer this essential structure from potential detrimental twisting, shearing, torsion, and compression forces throughout gestation, and specifically during labor and delivery. The arterial components of the umbilical cord are further protected by the presence of Hyrtl’s anastomosis between the two respective umbilical arteries. Abnormalities of the umbilical cord are uncommon yet include excessively long or short cords, hyper or hypocoiling, cysts, single umbilical artery, supernumerary vessels, rarely an absent umbilical cord, stricture, furcate and velamentous insertions (including vasa previa), umbilical vein and arterial thrombosis, umbilical artery aneurysm, hematomas, and tumors (including hemangioma angiomyxoma and teratoma). This commentary will address current perspectives of prenatal sonography of the umbilical cord, including structural anomalies and the potential impact of future imaging technologies.

Massive Extra-Abdominal Umbilical Vein Varix: A Case Report

Umbilical vein varices are rare umbilical cord anomalies that typically occur intra-abdominally. Extra-abdominal umbilical vein varices are exceedingly rare and usually diagnosed postnatally on gross pathologic examination. Umbilical vein varices have been associated with increased risk of fetal anemia, cardiac abnormalities, and intrauterine fetal demise. This case report discusses a patient who presented with a massive extra-abdominal umbilical vein varix, whose infant was ultimately delivered due to fetal distress and died in the neonatal period. This report also discusses associated fetal conditions and guidelines for antenatal testing and surveillance of known umbilical vein varices.

Severe fetal anemia as a consequence of extra-abdominal umbilical vein varix: A case report and review of the literature

Umbilical vein varix is associated with a high incidence of fetal anomalies and perinatal complications. There are two types of umbilical vein varix: fetal intra-abdominal and extra-abdominal. Herein, a case is reported of severe fetal anemia with extra-abdominal umbilical vein varix. A 33-year-old primigravida was referred to our hospital for fetal growth restriction, fetal cardiomegaly, and decreased fetal movements at 26 weeks' gestation. A Doppler assessment showed an elevated middle cerebral artery peak systolic velocity at 2.2 MoM, suggesting fetal anemia. Umbilical vein varix had caused intermittent turbulent flow, provoking hemolytic anemia. Intrauterine transfusion improved fetal circulatory failure and anemia and prolonged gestational period. At 33 weeks' gestation, the patient underwent cesarean delivery due to nonreassuring fetal status. Pathological analysis revealed focal loss of vascular smooth muscle of the umbilical vein. Extra-abdominal umbilical vein varix has been reported in 14 cases including this case. The antenatal diagnosis rate is reported to be 79%; fetal heartbeat abnormalities and fetal deaths were reported as 50% and 14%, respectively. Eighty-six percent of patients had intra-umbilical cord thrombosis, but currently this is the only case of hemolytic anemia. Furthermore, extra-abdominal umbilical vein varix may present as fetal hydrops with anemia. During ultrasound examination of fetal anemia, umbilical cord screening should be performed with caution.

Perinatal outcomes of fetal intra-abdominal umbilical vein varix: a multicenter cohort study

OBJECTIVES

To investigate the perinatal outcomes of fetuses with antenatal diagnoses of intra-abdominal umbilical vein varix (UVV).

METHODS

A multicenter retrospective study was conducted in four countries on fetuses diagnosed with intra-abdominal UVV between 2012 and 2019. Collected data included gestational age (GA), UVV maximum diameter at diagnosis and delivery, associated anatomical and chromosomal anomalies, birth weight, and neonatal outcomes.

RESULTS

Twenty fetuses were identified, of which 20% had associated chromosomal and/or anatomical abnormalities, most resulting in poor outcomes (either intrauterine fetal death or pregnancy termination). Mean maternal age was 34.1 ± 7.0 years, UVV was diagnosed at 26.5 ± 4.5 weeks of GA on average with a maximum diameter of 12.0 ± 4.0 mm. Mean GA at delivery was 35.4 ± 5.6 weeks. Survival rate was 85%.

CONCLUSION

Our study shows a satisfactory outcome when intra-abdominal UVV is an isolated finding, with minimal obstetrical and perinatal consequences. The prognosis is worse when UVV is associated with other anomalies.

A Case Report of Umbilical Vein Varix with Thrombosis: Prenatal Ultrasonographic Diagnosis and Management

Umbilical vein varix (UVV) is a very rare cord anomaly associated with intrauterine fetal death and fetal anomaly. We describe a case of extra-abdominal UVV with thrombosis. UVV was diagnosed at 23 weeks of gestation for the first time by ultrasonographic screening. Peak systolic velocity (PSV) near the UVV was partially increased up to about 100 cm/s, and blood flow was not detected in one of the umbilical arteries at 28 weeks of gestation. Therefore, the mother was hospitalized to monitor alterations of the PSV of the UVV frequently. Because the PSV of the UVV showed a sudden rapid increase up to about 150 cm/s at 32 weeks of gestation, she underwent emergent cesarean section on the same day to avoid sudden umbilical cord occlusion. The infant's birth weight was 1,744 g, and the Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. The pathological examination showed UVV with thrombosis and an occlusion in one of the umbilical arteries. The neonatal laboratory data showed no coagulopathy. Based on our experience with this case, frequent ultrasonographic examination should be performed to detect the acute thrombosis in the case of extra-abdominal UVV, especially during the preterm period.

Large fetal intra-abdominal umbilical vein varix: Antenatal sonographic diagnosis and follow-up

Fetal intra-abdominal umbilical vein varix is an uncommon antenatal finding defined as focal dilatation of umbilical vein >9 mm or more than two standard deviations above the mean for the gestational age. We report the case of a 28-year-old gravida 2 diabetic lady, who presented at 35 weeks of gestation, whose antenatal ultrasonography showed a cystic lesion of size 4 × 3.8 cm showing turbulent venous flow in the fetal abdomen in continuity with the umbilical vein, diagnosed as umbilical vein varix without any other anomaly. Postnatal ultrasonography showed size reduction and thrombosis of varix. Isolated umbilical vein varix has a favorable outcome, whereas those associated with other structural anomalies have a variable prognosis. This case was reported because of the unusually large size of varix with a good outcome and also to stress the importance of detailed sonography and close fetal monitoring in the presence of umbilical vein varix.

Is umbilical vein varix associated with changes in cerebroplacental ratio?

Objective: We aimed to review a single-center experience in follow-up and management of fetuses with umbilical vein varix (UVV) and to assess the effect of UVV on fetal Doppler parameters.Methods: We reviewed retrospectively maternal antenatal records, delivery records, and newborn records to identify cases of UVV. Further, we retrospectively compared 25 fetuses with isolated UVV and available cerebroplacental ratio (CPR) analysis with 75 matched controls.Results: We identified 67 cases of UVV. The median gestational age (GA) at diagnosis was 34 weeks (range: 26-41 weeks). The average diameter of UVV at diagnosis was 10.1 mm (range: 9-14 mm). The median GA at delivery was 36 + 6 (range: 33-41 weeks), with an average birth weight of 2918 g (range: 1278-4140 g). There was a single case of intrauterine death at 35 weeks. CPR was 2.13 ± 0.62 in isolated UVV group compared with 1.84 ± 0.61 in the control group (p < .05). Other Doppler parameters did not differ between fetuses with UVV compared with controls.Conclusions: CPR was significantly increased in the UVV group compared with control fetuses. This finding suggests that UVV is not associated with chronic fetal oxygen deprivation; it, therefore, may contribute to our understanding of the pathophysiology explaining abnormal pregnancy outcome in cases with UVV.

Fetal Intra-abdominal Umbilical Vein Aneurysm

Importance

Fetal umbilical vein aneurysm is an uncommon anomaly that accounts for approximately 4% of umbilical cord abnormalities. The rate of intrauterine fetal death is reported to be approximately 4% to 5%, higher than the background rate of 0.7% that is generally reported during pregnancy.

Objective

The aim of this study was to review the pathophysiology, diagnosis, and clinical management of fetal umbilical vein aneurysm.

Evidence Acquisition

Advances in high-resolution ultrasound combined with color Doppler and 3-dimensional rendering have contributed to an increased understanding of the fetal venous circulation in recent years.

Results

When the diagnosis of umbilical vein aneurysm is made, the patient should undergo a detailed ultrasound evaluation of the fetal anatomy, including fetal echocardiography, to exclude associated anomalies. Amniocentesis should be offered when other anomalies are found. Patients should be informed about the potential for an unfavorable outcome of pregnancy and should undergo close ultrasound surveillance to assess the size of the aneurysm, as well as any evidence of thrombosis or signs of hydrops.

Conclusions

The main prognostic feature associated with a poor outcome of umbilical vein aneurysm seems to be the presence of other anomalies. Early diagnosis is associated with a somewhat worse prognosis, and most fetal deaths have been observed between 27 and 30 weeks of gestation. In the third trimester, it is reasonable to perform serial ultrasound examinations to assess fetal growth, the size of the aneurysm, and the blood flow pattern within the aneurysm.

Comprehensive imaging review of abnormalities of the umbilical cord

A complete fetal ultrasonographic (US) study includes assessment of the umbilical cord for possible abnormalities. Knowledge of the normal appearance of the umbilical cord is necessary for the radiologist to correctly diagnose pathologic conditions. Umbilical cord abnormalities can be related to cord coiling, length, and thickness; the placental insertion site; in utero distortion; vascular abnormalities; and primary tumors or masses. These conditions may be associated with other fetal anomalies and aneuploidies, and their discovery should prompt a thorough fetal US examination. Further workup and planning for a safe fetal delivery may include fetal echocardiography and karyotype analysis. Doppler US is a critical tool for assessment and diagnosis of vascular cord abnormalities. US also can be used for follow-up serial imaging evaluation of conditions that could result in fetal demise. Recent studies suggest that three- or four-dimensional Doppler US of the fetal umbilical cord and abdominal vasculature allows more accurate diagnosis of vascular abnormalities. Doppler US also is invaluable in assessment of fetal growth restriction since hemodynamic changes in the placenta or fetus would appear as a spectral pattern of increased resistance to forward flow in the fetal umbilical artery. Early detection of umbilical cord abnormalities and close follow-up can reduce the risk of morbidity and mortality and assist in decision making.

The Triple Test Markers Profile Among Fetuses and Children Diagnosed With Umbilical Vein Varix

Umbilical vein varix (UVV) is defined as a focal enlargement of the umbilical vein and represents approximately 4% of fetal umbilical cord malformations. The reported neonatal outcome of fetuses with UVV varies widely due to its rarity, hence the small sample sizes of the case series in the literature. Earlier studies reported high fetal mortality, but more recent reports have demonstrated no association between UVV and intrauterine fetal death. A recent study has described a possible association between UVV diagnosed prenatally and child developmental delay. The present study of fetuses with UVV was done to evaluate and compare the levels of triple test serum biomarkers used for Down syndrome screening (human chorionic gonadotropin, α-fetoprotein, and unconjugated estriol) between a group of fetuses with uneventful obstetric outcome versus a subgroup of children with developmental delay.

Clinical characteristics and outcomes of antenatal fetal intra-abdominal umbilical vein varix detection

Objective

This study reviewed clinical characteristics of fetal intra-abdominal umbilical vein (FIUV) varices that were detected during antenatal ultrasound examinations.

Methods

Between January 2006 and January 2012, 121 cases of FIUV varices were detected and 7 cases were lost to follow-up. We retrospectively reviewed the medical records of 114 patients and neonates.

Results

From a total 96,553 ultrasound examinations in 43,995 pregnancies, 121 cases of FIUV varices were identified (2.8 per 1,000 pregnancies). Gestational age at diagnosis was 32.0 ± 2.9 weeks (range, 20.1-36.3 weeks), the mean diameter of the FIUV varix was 12.6 ± 2.1 mm (range, 8.0-21.0 mm) at initial diagnosis and the mean maximal diameter was 13.1 ± 2.3 mm (range, 8.0-21.0 mm) during follow-up. The most severe pregnancy complications included one case of intrauterine fetal death and another case of fetal hydrops. Associated fetal anomalies (n = 11, 9.6%) detected by ultrasonography included bilateral renal pelvis dilatation, ventriculomegaly, cryptorchidism, incomplete renal duplication and pulmonary sequestration. A total of 104 cases (91.2%) were delivered at term and 10 cases (8.8%) were preterm deliveries before 37 weeks of gestation.

Conclusion

FIUV varices that are not associated with fetal anomalies based on ultrasound examination during prenatal care have favorable pregnancy outcomes. Nevertheless, close fetal monitoring is recommended to decrease perinatal complications.

Four cases of fetal intra-abdominal umbilical vein varix: a single centre's approach to management

Fetal intra-abdominal umbilical vein (FIUV) varix is a rare prenatal abnormality characterised by a focal intrahepatic or extrahepatic dilatation of the intra-abdominal portion of the umbilical vein. Usually, it is an isolated finding, but in some cases it can be associated to other fetal anomalies. Thrombosis is a possible complication of FIUV varix and it can lead to poor fetal or neonatal outcome. We describe four consecutive cases of FIUV varix diagnosed in our Unit and managed with low-dose aspirin (LDA) prophylaxis until the 35th week of gestation. None of the fetuses developed thrombosis of the varix and the neonatal outcomes were good in all the cases.

Intra-abdominal umbilical vein varix associated with fetal cardiac failure: a pitfall to the prenatal diagnosis of α-zero-thalassemia

Hydrops fetalis related to homozygous α-thalassemia is a rare condition in Western Europe. We report a case of fetal cardiac failure that occurred after a second-trimester diagnosis of fetal umbilical vein aneurysm that was postnatally related to α-thalassemia.

Two- and three-dimensional sonographic diagnosis of fetal intra-abdominal umbilical vein varix: a case report

Fetal intra-abdominal umbilical vein varix is a rare condition characterized by focal dilatation of the umbilical vein of the fetus. We report a case of fetal intra-abdominal umbilical vein varix associated with additional sonographic abnormalities and detected at 31 weeks' gestation. Several follow-up sonographic examinations were performed, and the prenatal findings were confirmed on postnatal ultrasound. The diagnosis was facilitated by the use of three-dimensional power Doppler sonography.

Ultrasonographic evidence of intra-abdominal umbilical vein dilatation: is it a true varix?

Fetal intraabdominal umbilical vein (FIUV) dilatation, or varix, is a rare ultrasonographic (US) finding of focal dilatation of the umbilical vein. This article describes FIUV tortuosity in cases with suspected varix and provides ultrasonographic criteria for its diagnosis. Cases of suspected FIUV varix referred to our unit for final diagnosis and follow-up were studied. Each woman underwent comprehensive US evaluations that included basic grayscale scan and color Doppler scan. In 12 singleton pregnancies, primary grayscale scan confirmed FIUV dilatation. Supplementary color Doppler scans, however, revealed linear bidirectional blood flow and FIUV tortuosity in all cases. Color Doppler scans did not depict true FIUV dilatations or varix but rather a tortuous course of the vein. A normal pregnancy outcome can be expected in these cases.

Isolated fetal intra-abdominal umbilical vein varix: clinical importance and recommendations

This series describes a single center's experience in follow-up and management of fetuses with an isolated fetal intra-abdominal umbilical vein varix. All cases with a fetal intra-abdominal umbilical vein varix that were diagnosed or referred to our medical center over 15 years were followed and managed. The definition of a fetal intra-abdominal umbilical vein varix used was a segment dilated to 9 mm or greater or at least 50% wider than the diameter of the adjacent umbilical vein. Over the 15-year period, our center had approximately 65,000 births with 28 cases of isolated fetal intra-abdominal umbilical vein varices: a prevalence rate of 1 case per 2300 births. Three of the 28 cases (10.7%) had intrauterine growth restriction. Five of 30 fetuses (17%) showed turbulent flow in the varix. We had no cases of intrauterine fetal death, and 27 of the 28 neonates had good outcomes. In contrary to earlier reports, we found that when a fetal intra-abdominal umbilical vein varix is isolated, a good fetal outcome is expected. On the basis of our experience, we have changed our policy and do not recommend inducing preterm labor. Nevertheless, close fetal surveillance until delivery is warranted.