Intra-abdominal Umbilical Vein Research Articles

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

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. A 28-year-old pregnant woman was diagnosed with FIUVV via ultrasound at 26weeks 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. 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 32weeks of gestation, spontaneous echo contrast (SEC), which indicates increased echogenicity, appeared. At 35weeks 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. 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.

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). 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. 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 39weeks in neither the cohort (38.7weeks) nor the pooled literature (37.6weeks). An i-FIUVV in singletons is not associated with an increased IUFD risk up to 39weeks 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 39weeks of gestation. After 39weeks of gestation, data on fetuses with i-FIUVV and their outcomes are lacking.

Isolated fetal intra-abdominal umbilical vein varix: A population-based review of obstetrical and neonatal outcomes.

To assess obstetrical and neonatal outcomes associated with isolated fetal intra-abdominal umbilical vein varix (FIUVV).

Differences in umbilical vein predict placental sharing and outcome in monochorionic twins with selective growth-restriction

To examine the association between umbilical venous diameters and flow with placental sharing and adverse outcomes in monochorionic twin pregnancies diagnosed with selective fetal growth restriction (sFGR). The venous placental territory determines the oxygenated blood flow to the fetuses. Unequal placental sharing is considered the main contributor but is not yet quantifiable during pregnancy. Prospective cohort study of monochorionic diamniotic twin pregnancies diagnosed with sFGR. The following ultrasound variables were measured: intra-abdominal and free loop diameter of the umbilical vein (UV), estimated fetal weight (EFW), and cord insertions. The time-averaged maximum velocity in the intra-abdominal UV was measured and used to calculate UV-flow. Ratios (larger/smaller twin) were used for analysis. Adverse outcome was defined as the occurrence of fetal demise or birth before 34 weeks. We included 102 consecutive sFGR pregnancies, of which 88 placentas (86%) underwent injection studies with barium sulfate. The overall survival was 89%: 7 cases with single fetal demise (7%), 5 with double demise (5%), and 5 neonatal deaths (5%) occurred. Univariable linear regression analysis showed a significant association for all of the variables with placental sharing. In multivariable analysis, the UV-variables and a discordant cord insertion remained significantly associated with placental sharing. EFW differences and a concordant or intermediate cord insertion were not significantly associated with placental sharing. Logistic regression and receiver operating characteristics curve analysis demonstrated that EFW discordance and the cord insertion site had a poor predictive accuracy for an unequally shared placenta or an adverse outcome. In contrast, the predictive accuracy of the UV-variables was fair. Differences in UV-diameter and flow between the twins at the time of sFGR diagnosis inform us of the placental sharing, more so than differences in EFW. Differences in UV-variables between the twins also seem to increase the risk of fetal demise and birth before 34 weeks.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Umbilical venous diameter and flow in monochorionic diamniotic twin pregnancy: association with placental sharing and fetal demise.

To examine the association of umbilical venous diameter and flow in monochorionic diamniotic twin pregnancy with placental sharing and fetal demise. This was a prospective longitudinal cohort study of a consecutive series of monochorionic diamniotic twin pregnancies that underwent ultrasound assessments at 12, 16, 20 and 28 weeks' gestation. Fetal biometry (crown-rump length at 12 weeks or estimated fetal weight (EFW) thereafter) and cord insertion sites were recorded at each visit, as well as the diameter of the umbilical vein (UV) in both the intra-abdominal part and a free loop of the umbilical cord. Time-averaged maximum velocity in the intra-abdominal part of the UV was measured to calculate UV-flow. Univariate and multivariate linear regression analyses were performed to assess the relationship between intertwin ratios of these variables and placental sharing at 12, 16, 20 and 28 weeks' gestation. Placental sharing was calculated by dividing the larger by the smaller placental share, as measured on placental injection studies after birth. Additionally, the Mann-Whitney U-test and receiver-operating-characteristics-curve analysis were used to explore the relationship between the occurrence of fetal demise and intertwin differences in fetal biometry, cord insertion sites, UV diameters and flow at 12, 16, 20 and 28 weeks. Of 200 consecutive monochorionic twin pregnancies enrolled, injection studies were performed in 165 (82.5%) placentas. On univariate analysis, intertwin differences in fetal biometry, cord insertions and UV variables were associated significantly with placental sharing at 12, 16, 20 and 28 weeks' gestation. On multivariate analysis, intertwin differences in fetal biometry, cord insertions and all three UV variables remained associated significantly with placental sharing at 12 and 16 weeks. However, at 20 and 28 weeks, only the intertwin EFW ratio was associated consistently with placental sharing. Fetal demise of one or both twins complicated 26 (13.0%) pregnancies. Differences in EFW and cord insertion sites were not associated significantly with fetal demise, while at 16 weeks, differences in intra-abdominal UV diameter and flow were associated with an increased risk of subsequent fetal demise. At 12 and 16 weeks' gestation, intertwin differences in UV diameter and flow reflect placental sharing more accurately than do differences in fetal growth and cord insertion sites. At 16 weeks, discordance in intra-abdominal UV diameter and flow is also associated with an increased risk of fetal demise. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

VP20.06: Fetal intra‐abdominal umbilical vein varix: retrospective study and review of literature

To investigate the ultrasound characteristics, associations and obstetric outcome in pregnancies with intra-abdominal umbilical vein varix of the fetus. It was a retrospective cohort study conducted over two years i.e., from March 2019- February 2021. Data was collected from ultrasound records, antenatal and intra- partum records. For the neonatal outcome patients and respective consultants were followed up by telephonic calls. The data collected was demographic characteristics, varix characteristics (gestational age at diagnosis, size, progression, turbulence, thrombus formation, associated malformations and genetic), obstetric complications (fetal growth restriction/ IUFD) and neonatal outcome. Descriptive statistics (means, standard deviations, and percentages [%]) were calculated using SPSS, version 21.0 (SPSS Inc, Chicago, USA). Over the period of 2 years six cases of FIUVV were diagnosed making the incidence of FIUVV of 5/10000 pregnancies. Incidence of isolated FIUVV was 4.4/10000 cases. The mean gestational age at diagnosis was 25 weeks 3days with earliest diagnosis at 19w1d. Aneuploidy screening was done in five of cases with low risk for trisomy 21, 18 & 13 as outcome. The mean varix size was 11.85mm±2.28 mm (range 8.9mm-14.8 mm). No incidence of turbulence or thrombus formation within the varix was seen in the current study. One case had absent DV with anomalous connection of umbilical vein with IVC. One Perinatal death after planned LSCS at term & sudden IUFD at 33 weeks were noted in this study. Detailed anatomical scan and counselling should be done after FIUVV diagnosis. The fetal surveillance should be increased to look for major dilatation thombus or FGR. Longer analysis on the large population is needed to study the association of controls with the outcome. Also, long term studies are needed to for any delayed consequences affecting the adult life of these fetuses.

Z-Score Reference Ranges for Umbilical Vein Diameter and Blood Flow Volume in Normal Fetuses.

To establish Z-scores for the diameter and blood flow volume of the umbilical vein (UV) in normal fetuses. This was a prospective study involving 907 normal fetuses. We measured the diameter (Duv) of two different segments of the UV (FUV: the free loop of the UV; FIUV: the fetal intra-abdominal UV). Next, we calculated the blood flow volume (Quv). Z-scores were created for both Duv and Quv using gestational age, femur length, and biparietal diameter as independent variables. We successfully acquired 858 (94.6%) normal fetal measurements. Between 20 and 39 weeks, the Duv of the FUV and FIUV increased from 0.38 to 0.80 cm and from 0.33 to 0.70 cm, respectively. The Quv of the FUV and FIUV increased from 32.66 to 381.88 ml/min and from 31.50 to 360.15 ml/min, respectively. Linear or quadratic regression models were best fitted between the parameters of UV and the independent variables. Z-scores were successfully determined for both the Duv and Quv. The calculation of Z-scores for the Duv and Quv is simple by applying standard statistical methods. These Z-scores may be useful to evaluate placental circulation and provide a rationale for monitoring and evaluating the prognosis of fetuses.

VP02.24: Umbilical vein varix: does it really need stringent monitoring?

Fetal intraabdominal umbilical vein varix (FIUVV) is a focal dilatation of the intraabdominal but extrahepatic portion of the umbilical vein. Here we present two cases where FIUVV was detected in the third trimester – one at 29 weeks and the other at 37 weeks. The detailed structural analysis was normal. Monitoring was done in the form of daily kick count, fortnightly antenatal visits and four weekly ultrasounds. We did not observe any increase in the size of the varix, turbulence in the flow or thrombosis during follow up scans. One was delivered at 37 weeks due to severe FGR and other at 38 weeks due to reduced fetal movements. FIUVV mandates a detailed anatomical survey. Invasive testing is recommended only if there are associated abnormalities. There is no or minimal increased risk of complications during pregnancy. The frequency of monitoring during pregnancy is still not established. Later the diagnosis of the varix, less frequent is the monitoring and better is the outcome. Supporting information can be found in the online version of this abstract Supporting Information Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

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.

Fetal intra-abdominal umbilical vein varix: retrospective cohort study and systematic review and meta-analysis.

To investigate the ultrasound characteristics and outcome of pregnancies with fetal intra-abdominal umbilical vein varix (FIUVV). Cases of FIUVV managed at our tertiary university hospital over an 8-year period were reviewed. Information retrieved included gestational age and diameter of the umbilical varix at diagnosis, increase in varix diameter, associated ultrasound or chromosomal anomalies and pregnancy outcome. Furthermore, a systematic review and meta-analysis of series of FIUVV in the literature was performed to assess the incidence of chromosomal anomalies, small-for-gestational age infants and intrauterine fetal demise (IUFD), and to pool odds ratio (OR) estimates on the relationship between the incidence of these outcomes and the presence of additional associated ultrasound anomalies. Thirteen cases of FIUVV were included in the cohort study. Additional ultrasound anomalies were found in two (15.4%) of 13 cases. One case of IUFD was observed and no case of chromosomal anomaly or thrombosis of varix was recorded. A total of five studies comprising 254 cases met the inclusion criteria of the systematic review. FIUVV was associated with additional ultrasound anomalies (non-isolated FIUVV) in 19% (95% CI, 10.9-29.1%) of cases. No case of chromosomal abnormality or IUFD was reported in fetuses with isolated FIUVV. In contrast, in the group of non-isolated FIUVV, the incidence of chromosomal anomalies was 19.6% and that of IUFD was 7.3%, with ORs of 14.8 (95% CI, 2.9-73.0) and 8.2 (95% CI, 1.05-63.1), respectively, when compared with the group of isolated FIUVV. When isolated, the outcome of cases affected by FIUVV is usually favorable. In about 20% of cases, additional ultrasound anomalies are found, which are associated with an increased risk for chromosomal abnormalities and IUFD. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Fetal Ductus Venosus Pulsatility Index and Diameter during Second and Third Trimester of Gestation

The ductus venosus is a small funnel shaped vessel found posterior to the fetal liver connecting the intra-abdominal umbilical vein and the inferior vena cava. It is one of the three physiological shunts in the fetus. The main objective of this study is to construct the reference table and normogram for fetal ductus venosus Pulsatility Index and diameter with gestational age. This was a prospective cross sectional study conducted during August 2011 to July 2012 taking 294 uncomplicated pregnancies using systemic random sampling method. Three measurements were made for ductus venosus diameter and Pulsatility Index in each fetus during period of fetal quiescence. The ductus venosus diameter at <20weeks, 20-25 weeks, 25-30 weeks, >30 weeks were 1.16, 1.31, 1.62, 1.81 and Pulsatility Index at <20weeks, 20-25 weeks, 25-30 weeks, >30 weeks were 0.41, 0.44, 0.41 and 0.41 respectively. The mean diameter of the ductus venosus was linear across gestational age. The Pulsatility Index shows a scattered distribution across the gestational age.

Fetal Intra-abdominal Umbilical Vein Varix: A Case Report and Literature Review

Fetal intra-abdominal umbilical vein (FIUV) varix is a rare malformation of the umbilical cord. This is a critical situation due to discrepancies in outcomes varying from normal to high rates of complications and fetal mortalities. We report the observation of a FIUVV vein diagnosed precociously at 22 weeks with a quiet increasing of the diameter by 31 weeks. The outcome was favourable and close monitoring after birthshowed no anomalies. Despite a good prognosis it seems that a close monitoring is essential in antenatal period.

Intra-Abdominal Umbilical Vein Varix – A Case Report

AbstractThe incidence of the fetal intra-abdominal umbilical vein varix condition is very rare and has been associated with fetal hydrops, IUGR and still birth A 26-year-old primigravida was referred for routine antenatal scan. The scan at 30 weeks showed an intra-abdominal ovoid structure superior to the fetal bladder. Color flow Doppler revealed venous flow in continuity with the umbilical vein. A diagnosis of umbilical varix was made. The venous flow was present throughout the lesion, suggesting the absence of thrombi. There was no evidence of fetal hydrops. Subsequent scans at regular intervals showed no increase in size of the umbilical varix. The patient had an uneventful elective cesarean section at 39 weeks. Postnatal assessment and a follow-up neonatal cardiac echo scan were normal. Our case supports the new emerging evidence that pregnancy outcome in cases of isolated fetal umbilical vein varix is generally good. Caution must be exercised against unnecessary early induction and costly preterm births

Fetal Intra-abdominal Umbilical Vein Varix Complicated with Patent Ductus Venosus and Atrial Septal Defect

Umbilical vein varix has diverse clinical features and an unpredictable course during the pregnancy and/or perinatal period. We report a rare case of isolated fetal varix of the intra-abdominal umbilical vein, which was associated with fetal cardiomegaly. After birth, the umbilical vein varix remained with continuous blood flow through the patent ductus venosus. In addition, persistent cardiomegaly was complicated with an atrial septal defect.

P15.01: Umbilical cord anomalies: detection and expectations

Fetal ultrasonographic screening has to include assessment of the umbilical cord for possible abnormalitiesthat can be: hypercoiled cord and nuchal cord, abnormal length and thickness of the cord, anomalies of the placental insertion site, vascular abnormalities and primary tumors of the cord. These conditions may be associated with fetal anomalies, chromosomal anomalies and intrauterine growth restriction. In our study we describe and analyze the ultrasound diagnosis and management of major umbilical cord abnormalities, considering the current knowledge on physiologic and pathologic aspects of each of them. A retrospective study was conducted in Universitary Emargency Hospital Bucharest over a 3-year period. We found 18 cases of single umbilical arteries, 6 cases of velamentous cord insertion, 3 of them associated with placental adherence abnormalities, partial placenta previa and one with vasa previa, 16 cases of more than 2 loops nuchal cord, 7 cases of true knot cord with 2 ultrasound undiagnosed cases, 5 true cord cysts and 3 cases of fetal intra-abdominal umbilical vein dilatation. A pregnancy with umbilical cord anomalies is more likely to be complicated with polyhydramnios, preterm delivery under 34 weeks, low birthweight, Caesarean delivery for fetal distress, perinatal death, admission to NICU and placental abnormalities compared with a pregnancy with a normal umbilical cord. We sustain that prenatal detection of umbilical cord abnormalities will decrease the number of emergent Caesarean sections and intrauterine fetal death. Safe fetal delivery, fetal echocardiography and karyotype analysis should be offered depending on risk associated to each umbilical cord abnormality. Doppler US is a critical tool for assessment and diagnosis of vascular cord abnormalities, whereas 3D/4D Doppler US of the fetal umbilical cord and abdominal vasculature allows a high accurate diagnosis of vascular abnormalities.

Umbilical vein varix: Importance of ante- and post-natal monitoring by ultrasound

Foetal intra-abdominal umbilical vein varix is rare. Colour Doppler ultrasonography helps distinguish this vascular anomaly. A detailed anatomic scan must be performed to exclude associated anomalies: forms associated with additional complications are found in 29 to 35% of the cases. Intra-uterine foetal demise (IUFD) is a complication of umbilical vein varix. However, recent studies are more reassuring. When foetal intra-abdominal umbilical vein varix is isolated, there is no reason to change the management of the pregnancy. Foetal sonographic follow-up is recommended, focusing on an increase in the size of the varix and the appearance of a clot. A particular clinical form, connecting the umbilicus to the extra-hepatic portal vein should be known, because of a high risk of thrombosis. On the basis of this finding, postnatal monitoring by ultrasound is necessary.

Fetal venous circulation in monochorionic twin pregnancies with placental insufficiency: prediction of acidemia at birth or intrauterine fetal death

To investigate fetal venous Doppler measurements in monochorionic twin pregnancies complicated by placental insufficiency and the relationship between fetal venous flow and acidemia at birth or intrauterine fetal death. This was a prospective study of 18 monochorionic twin pregnancies with placental insufficiency. Inclusion criteria were monochorionic-diamniotic twin pregnancy, abnormal umbilical artery (UA) Doppler indices, intact membranes and absence of fetal congenital abnormalities. Cases of twin-to-twin transfusion syndrome were excluded. The following Doppler measurements were studied: UA pulsatility index (PI), ductus venosus PI, middle cerebral artery PI and peak systolic velocity, intra-abdominal umbilical vein (UV) time-averaged maximum velocity (TAMXV) and left portal vein (LPV) TAMXV. Doppler parameters were transformed into Z-scores (SD values from the mean) or multiples of the median according to normative references. UA pH < 7.20 occurred in nine (25.0%) neonates, pH < 7.15 in four (11.1%) and intrauterine death in four (11.1%) fetuses. The UV-TAMXV and LPV-TAMXV Z-scores were significantly lower in the group with pH < 7.20 or intrauterine fetal death (-1.79 vs -1.22, P = 0.006 and -2.26 vs -1.13, P = 0.04, respectively). In cases with pH < 7.15 or intrauterine fetal death, UV pulsations were more frequent (50.0% vs 10.7%, P = 0.03) and UV-TAMXV Z-score was significantly lower (-1.89 vs -1.26, P = 0.003). Mixed effects logistic regression analysis, accounting for the paired nature of the outcomes for the two twins in each pregnancy, demonstrated that the UV-TAMXV Z-score significantly predicted UA pH at birth < 7.20 or intrauterine fetal death. The Doppler parameter that independently predicted pH < 7.15 or intrauterine fetal death was presence of pulsation in the UV. UV Doppler parameters may predict acidemia at birth or intrauterine fetal death in monochorionic twins complicated by placental insufficiency.

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

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

Comment on “Long‐term outcomes of children with umbilical vein varix diagnosed prenatally”

We read with interest the article by Melcer et al. 1 describing the postnatal neurodevelopmental outcome of fetuses with intra-abdominal umbilical vein varix (UVV). The authors report that developmental delay may be present in as much as 42% of ex-UVV children. However, there are some aspects of the study design who may have introduced a bias in their results. Firstly, the controls were not matched for the family's socioeconomic status (which is an important confounder in long-term neurodevelopment studies), and the high incidence of preterm delivery (72% in the study group) may have different causes in cases and controls. Secondly, a telephone questionnaire for both the study and the control group, based on the Ages and Stages Questionnaire (ASQ), was used as a screening tool to select children for indepth neurodevelopmental assessment. However, the ASQ is supposed to be filled in by parents, or by someone who interacts with the child. In particular, the ASQ instructions highlight some important aspects of test administration: “Try each activity with your baby before marking a response”,“Make completing this questionnaire a game that is fun for you and your child”, “Make sure your child is rested and fed”. 2 How can these requirements be achieved with a phone interview? Actually, of 10 children with UVV with abnormal ASQ results who were formally assessed, only four were confirmed to have some form of delay. Only one child in the control group had formal assessment. Finally, there is increasing evidence that conditions affecting fetal cardiovascular function, for example, congenital heart disease, may have a detrimental effect on neurodevelopmental outcomes. 3 However, it is reasonable to think that not just the mere presence of ad ilated umbilical vein, but some other mechanism such as circulatory disturbance and thrombus formation may cause brain damage, which eventually results in developmental delay. The current evidence does not provide us with any data on such mechanisms. In conclusion, although Melcer and colleagues should be congratulated for their observation, the estimate of the risk of developmental delay reported in their article (42% in UVV vs 4% in controls) may not be accurate, and should not be used in parental counseling as it could even lead to unwarranted terminations of pregnancy.

Abnormal ductus venosus pulsatility index in the absence of concurrent umbilical vein pulsations does not indicate worsening fetal condition

Recordings of blood flow velocity waveforms in the ductus venosus (DV) and umbilical vein (UV) are routinely used in order to predict fetal condition in high-risk pregnancies. The aim of this study was to investigate the relationship between pathological blood flow in the two vessels and perinatal outcome. High-risk pregnancies (n = 11 863) admitted from 1993 to 2011 for blood-flow examination, including recordings of DV pulsatility index for veins (DV-PIV) and UV pulsations, were included. The results were related to perinatal outcome, using the last Doppler examination prior to delivery in the analysis. Abnormal DV-PIV was observed in 3.9% of cases, intra-abdominal UV pulsations in 1.3% and pulsations in the cord in 0.7%. As expected, the rate of UV pulsations increased with increasing DV-PIV Z-score. Fetuses with a pathological DV-PIV, but without UV pulsations, showed fewer signs of compromise. This was also true for cases with a DV-PIV ≥ 4 SDs above the mean (53.7% had steady flow in the UV). In contrast, the occurrence of UV pulsations seemed to be an indicator of fetal compromise, regardless of level of DV-PIV. Abnormal fetal venous blood velocity is related to adverse outcome in high-risk pregnancies. However, abnormal DV-PIV is not a reliable indicator of fetal compromise unless UV pulsations are concurrently present, and should not be regarded an indication for emergency delivery.