Abnormalities of the intra-abdominal fetal umbilical vein: reports of four cases and a review of the literature

Improving prenatal detection of abdominal supraumbilical anomalies: The sonographic examination of fetal anechoic spaces of upper abdomen revisited

Visualization of the axial plane of the fetal abdomen is mandatory to obtain abdominal biometry in the assessment of fetal growth in the second and third trimesters. The main anatomic landmarks that must be identified in this view include the fetal stomach and the intrahepatic portion of the umbilical vein, which are easily identifiable as they appear anechoic on ultrasound. The gallbladder is the other prominent anechoic structure in this plane. Focused study of the morphological characteristics of, and spatial relationship among, these three anechoic spaces is a simple technique to detect anomalies involving fetal upper abdominal organs. In this review, the sonographic features of those conditions that can be detected using this technique, which was termed the Fetal Examination of the Anechoic Spaces of upper abdomen Technique (FEAST), are classified and illustrated.

A new classification of congenital abnormalities of UPVS: sonographic appearances, screening strategy and clinical significance

The umbilical–portal venous system (UPVS) plays an important role in embryonic development, as well as a significant blood circulation system to ensure the normal blood supply of fetal heart and brain and other vital organs. Congenital anomalies of UPVS contain many subtypes with a broad spectrum of manifestations and prognoses. Furthermore, because of fetal small lumen of UPVS, the sonographic evaluation remains difficult in utero. Appreciation of normal embryology and anatomy of UPVS is essential to an understanding of sonographic characteristics of anomalies of UPVS and fetal sequential changes. Through reviewing previous references and our experience with congenital abnormalities of UPVS, a new comprehensive classification is proposed. The new classification identifies three types of congenital abnormalities of UPVS based on morphological abnormalities and shunts. The embryology and etiology, sonographic, clinical and prognostic characteristics of each subtype of the new classification are described in detail. Knowledge of congenital abnormalities of UPVS can give sonographers a clue and aid prenatal sonographic diagnosis. The purpose of this article is to help the sonographers to understand the new classification of congenital abnormalities of UPVS, master the sonographic characteristics of each subtype and prenatal ultrasonographic screening strategy, and guide subsequent appropriate counseling and management.

Fetal umbilical-systemic shunt with a positive issue

We herein report the case of abnormal umbilical-venous return in which the antenatal ultrasound enabled us to establish the diagnosis of umbilical-systemic shunt (Type 1 according to Achiron (Achiron and Kivilevitch, 2016)). Due to the concomitant associations of cardiomegaly, intrauterine growth retardation, oligohydramnios, and left-lobe hypoplasia with agenesis of the intrahepatic umbilical vein - left portal vein - ductus venosus, a poor prognosis (11.1% survival) was to be expected. In spite of development of pulmonary arterial hypertension at birth, which was promptly treated, the evolution was nevertheless good, both on clinical and ultrasound follow-up.

Ductus venosus-systemic shunt. Report of six cases and systematic review of the literature

Objective: To evaluate the ultrasonographic features and pregnancy outcomes in women with ductus venosus-systemic shunt and systematic review of the literature.Method: A computerized search was conducted to identify cases of ductus venosus-systemic shunt between September 2016 and January 2018. Six patients were identified. Antenatal records and neonatal outcomes are presented. A systematic Embase, SCOPUS, and Medline search of published literature from 1991 to 2018 was performed using the terms "ductus venosus," "agenesis," "absence," "absent," "missing," "aberrant," and "variant."Results: Additional structural anomaly such as esophageal atresia with tracheoesophageal fistula was observed in one case. In other case, termination of pregnancy was performed due to Down syndrome. Other two of the six fetuses were monochorionic multiple pregnancies. In our review of the literature, additional anomalies were observed in 9 (42%) of the 21 cases.Conclusion: Our observation suggests that ductus venosus-systemic shunt can be associated with Down syndrome. Detailed examination should be performed to rule out additional abnormalities. Prognosis is good if the pathology is isolated.

Ductus venosus agenesis and fetal malformations: what can we expect? - a systematic review of the literature

Background The ductus venosus agenesis (DVA) is a rare condition with a variable prognosis that relies partly on the presence of associated conditions. The purpose of our study was to analyze the literature regarding the post-natal outcome of fetuses with DVA associated with fetal malformations, in order to discuss the best management options for couples. Methods We performed a systematic review of the literature of MEDLINE and SCOPUS electronic databases in a 25-year period from 1992 to September 2017. Methods We found 340 cases of DVA associated with fetal abnormalities. The most common chromosomal abnormalities were: monosomy X (12/48, 25%), trisomy 21 (11/48, 22.9%) and trisomy 18 (6/48, 12.5%). From the 340 cases with DVA, in 31 cases the umbilical venous shunt type was not reported. Of the fetuses, 60.8% (188/309) had an extrahepatic umbilical venous drainage while 39.2% (121/309) presented an intrahepatic connection. The DVA was associated in 71 cases (23.0%) with cardiac abnormalities, in 82 cases (26.5%) with extracardiac abnormalities and in 85 cases (27.5%) with both cardiac and extracardiac abnormalities. Conclusion DVA associated with both cardiac and extracardiac malformations may confer a poorer fetal outcome, a clinically relevant fact that should clarify what can be expected from this entity and help prenatal counseling.

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.

Congenital Vascular Malformations of the Liver: An Association With Trisomy 21

A link between congenital vascular malformation (CVM) of the liver and trisomy 21 has been suggested. We reviewed all children with trisomy 21 referred for investigation to a specialist pediatric hepatobiliary unit (1985-2015). Forty-five children with trisomy 21 were identified; 7 (15%) had a defined CVMs (4 girls). All such infants were also diagnosed with a range of cardiac defects. CVMs were divided according to the nature of the vascular connection. Group (i) (n = 3): Abnormal venovenous anomaly. This included portocaval shunt and patent ductus venosus (n = 2). Group (ii) (n = 4): Involvement of all 3 vascular systems. Two infants had arterioportal hypertension caused by hepatic arteries feeding into a left portal vein aneurysm within the umbilical fissure. Two infants had more complex hepatic artery to hepatic vein shunts developing early cardiorespiratory failure with progressive jaundice. Our series shows a clear association between cardiac anomalies and CVM in children with trisomy 21.

Predicting outcome in 259 fetuses with agenesis of ductus venosus - a multicenter experience and systematic review of the literature (.)

OBJECTIVE

To evaluate prenatal predictors of postnatal survival in fetuses with agenesis of ductus venosus (ADV).

METHODS

This retrospective study reviewed our experience and the literature between 1991 and 2015. Prenatal findings were evaluated and perinatal morbidity and mortality was documented.

RESULTS

A total of 259 cases were included in the present analysis from our centers and 49 published studies (15 patients from our retrospective cohort review and 244 from literature review). The intrahepatic and extrahepatic shunts were present in 32.0% (73/226) and 67.7% (153/226), respectively. Cardiomegaly (n = 64/259, 24.7%), hydrops (n = 31/259, 12.0%) and amniotic fluid abnormalities (n = 22/259, 8.5%) were among the most frequent initial ultrasound findings. One hundred and forty-seven fetuses (56.8%) had ADV without structural anomalies while 112 (43.2%) had associated anomalies (cardiac anomalies (n = 66), extra-cardiac anomalies (n = 19) and both cardiac and extra-cardiac anomalies (n = 27)). The mean gestational age (GA) at ultrasound diagnosis was 22.9 ± 6.9 weeks while the mean GA at delivery was 34 ± 7.5 weeks. The overall neonatal survival was 57.1% (n = 148/259). The following factors were associated with survival: advanced maternal age, earlier GA at diagnosis, prematurity, increased nuchal translucency, pericardial effusion, associated cardiac defects (especially AVSD), chromosomal abnormalities, hydrops, hygroma and limb anomalies.

CONCLUSION

Fetal hydrops, the presence of associated congenital anomalies and premature delivery are associated with poor prognosis in fetuses with ADV.

A Benign Anomalous Umbilical Vein: Not All Umbilical Veins That Wander Are Lost

A rare case of an anomalous umbilical vein with a previously unreported outcome is described. Most reported cases of anomalous umbilical veins are associated with significant concurrent fetal anomalies and poor outcomes. Fetal magnetic resonance imaging was used in this case to confirm normal portal and hepatic venous vasculature. No other fetal anomalies were identified on ultrasound. The infant was delivered at term and is healthy at the age of 8 months. Parental anxiety regarding the diagnosis was the only adverse consequence of this incidental finding.

Agenesis of the venous duct: two cases of extrahepatic drainage of the umbilical vein and extrahepatic portosystemic shunt with a review of the literature

Agenesis of the venous duct is a rare congenital anomaly resulting in abnormal drainage of the umbilical vein into the foetal venous circulation. The clinical presentation and prognosis is variable, and may depend on the specific drainage pathways of the umbilical vein. We present two foetuses with agenesis of the venous duct, both associated with a postnatal portosystemic shunt, but with markedly different postnatal clinical courses. We also review all previously reported cases to better characterise this foetal disorder and the prognosis.

The prenatal diagnosis of isolated fetal varix of the intra-abdominal umbilical vein is associated with favorable neonatal outcome at term: a case series

OBJECTIVE

Varix of the fetal intra-abdominal umbilical vein (VFIUV) has been reported to be associated with an increased risk of adverse perinatal outcome and especially with intra-uterine fetal demise (IUFD). Induction of preterm birth, as early as 32-34 weeks gestation has been suggested to minimize this risk. We aimed to evaluate our center experience with the antenatal diagnosis of VFIUV and review the relevant literature.

METHODS

This is a retrospective case series of all cases (between 2004 and 2009) where the sonographic antenatal diagnosis of VFIUV was registered at any gestational age (GA). Ultrasound, maternal and newborn electronic medical records were used. Descriptive statistics were employed as appropriated and correlation coefficient (r) calculated.

RESULTS

We identified 24 women with fetuses, with isolated VFIUV (excluding one lost-to-follow-up). GA at diagnosis was 30.5 ± 4.4 weeks; 13 (56.5 %) cases were diagnosed <32 weeks. The mean VFIUV diameter was 13 ± 2.9 (range 9-20) mm and turbulent flow was reported in 7 cases (30.4 %). GA at birth was 37 ± 2.5 weeks. The small for gestational age rate was 4 % (1/23), while no case of IUFD occurred. The group induction of labor rate was 65.2 %, while 43 % (10/23) due to the diagnosis of VFIUV alone: 17 % (4/23) preterm and 26 % (6/23) at term. The cesarean rate was 17 % (4/23) and NICU admission was required for five neonates (21.7 %). The preterm induction of birth was related to a significantly increased risk for cesarean and neonatal morbidity (p = 0.015; p = 0.029, respectively). The mode of delivery was not associated with the GA at diagnosis, size/type of flow of VFIUV (r = 0.101; r = 0.727; r = 0.671, respectively) overall (r) = 0.4. All fetuses were live-born with normal follow-up at 2-60 months.

CONCLUSION

Isolated VFIUV has a favorable perinatal outcome at term, unrelated to the structural and flow characteristics of VFIUV. We show that follow-up for growth abnormalities with no preterm induction of birth is a safe maternal and neonatal approach.

Persistent right umbilical vein: a prenatal condition worth mentioning?

OBJECTIVES

To investigate the incidence and clinical impact of prenatally diagnosed persistent right umbilical vein (PRUV) in a referral population and to evaluate the findings together with those from previous publications.

METHODS

This was a retrospective analysis of 39 cases with PRUV diagnosed in three tertiary referral centers for prenatal medicine between 1996 and 2009. Fetuses with situs inversus, situs ambiguous and heterotaxy (left and right isomerism) were excluded. During the study period 46 653 consecutive high- and low-risk pregnancies were examined. The prenatal sonograms and neonatal outcome data of affected individuals were reviewed. Our findings were analyzed together with findings retrieved from the scientific literature.

RESULTS

Twenty-nine fetuses had an isolated PRUV as a single anomaly, whereas 10/39 (25.6%) were found to have PRUV accompanied by additional minor and major abnormalities. These anomalies comprised mainly cardiovascular, genitourinary and gastrointestinal malformations. In common with our series, previously published cases of isolated PRUV (n = 197) displayed an uneventful course of pregnancy and a favorable postnatal outcome. Sixty-six previously reported cases of PRUV with additional anomalies were identified in the literature. Intrahepatic umbilical drainage is the most frequent type of PRUV. Including our cases, there were 16 cases (5.3%) with extrahepatic drainage of PRUV, all of which had additional anomalies.

CONCLUSIONS

Consistent with previous reports, in the majority of cases (74.8%) PRUV is an isolated finding. While these cases carry an excellent prognosis, PRUV can be associated with severe congenital anomalies, so this finding should prompt detailed prenatal assessment of the fetus.

Abnormal direct entry of the umbilical vein into the portal vein: report of a case

Abnormalities of the intra-abdominal umbilical venous connections are rare congenital vascular anomalies. We report a case of an aneurismal dilatation of an umbilical vein directly connected to the portal vein, vital for the delivery of placental blood in the fetus. A term female newborn presented with a dilated umbilical vein detected by prenatal ultrasound. CT angiography revealed an aneurismal dilatation of a vascular structure, from the umbilical ring to the main portal vein. Follow-up CT angiography showed thrombus progression up to the level of SMV inlet. A laparotomy revealed that the normal course of the umbilical vein was absent. The aneurysm was resected and no thrombus was noted in the aneurysm. Post-operative ultrasound revealed an isolated thrombus at the right main portal vein that resolved spontaneously on the follow-up ultrasound. At the 6-month post-operative follow-up, the baby was well and without complications. Although not evaluated for the presence of a ductus venosus, this anomalous umbilical-portal venous connection might have been associated with an absent ductus venosus.

Prenatal diagnosis of varix of the fetal intraabdominal umbilical vein--case report

Varix of intraabdominal part of fetal umbilical vein is during a prenatal ultrasound scan seen as a hypoechogenic mass between anterior abdominal wall and lower edge of liver, and the diagnosis is confirmed when blood flow is seen during color Doppler examination. A case of prenatal diagnosis of this abnormality is presented, with review of contemporary literature regarding diagnosis and management as well as the outcome of such pregnancies.

Intraabdominal umbilical vein dilatation and term delivery. A case report and review of the literature

Dilatation of the fetal umbilical vein is a rare, most commonly isolated finding. Approximately 100 cases have been reported in the literature that describe different management approaches, especially regarding the time of delivery. We present a new case of umbilical vein dilatation diagnosed at 23 weeks' gestation as an isolated sonographic finding, in a fetus with short umbilical cord, delivered at 38 weeks' gestation. The clinical and sonographic features as well as the management options of this uncommon condition are shortly discussed.

Dilatation of the abdominal umbilical vein is associated with increased risk of thrombotic complications

Malformations of the umbilical vein are rare abnormalities diagnosed on prenatal ultrasound. They might be associated with fetal hydrops and fetal death. We report two newborn infants with prenatal diagnosis of umbilical vein dilatation who developed venous thrombosis and discuss the pre- and postnatal management of the constellation with special emphasis on antithrombotic treatment.

Absence of ductus venosus-importance of umbilical venous drainage site

OBJECTIVE

To evaluate the conditions associated with absent ductus venosus (ADV) diagnosed by prenatal ultrasonography.

METHODS

Retrospective review of 23 cases with ADV diagnosed in two tertiary referral centers with a general screening policy concerning Doppler assessment of the ductus venosus. The results are discussed together with 63 cases from a review of the literature.

RESULTS

In 19 fetuses the umbilical vein connected to the portal sinus, while the remaining four fetuses had extrahepatic umbilical venous drainage. Associated anomalies were present in 15 out of 23 fetuses: complex malformation syndromes (n = 6), chromosomal anomalies (n = 4), isolated cardiac defects (n = 4) and isolated extracardiac anomalies (n = 1). Eight fetuses had either no associated anomalies or minor anomalies. Hydropic changes were present in 12 of the 23 fetuses. In common with the reviewed cases, the presence of cardiac malformations, complex non-chromosomal malformation syndromes and hydrops was significantly associated with intrauterine or postnatal death while the type of umbilical venous drainage was not significantly different between survivors and non-survivors. However, among fetuses with no or minor associated anomalies the outcome was significantly better in the group without liver bypass.

CONCLUSIONS

ADV is significantly associated with fetal cardiac and extracardiac anomalies, aneuploidies and hydrops. Fetuses with liver bypass have an additional risk of developing congestive heart failure that significantly affects outcome, even if the fetal cardiovascular anatomy is otherwise normal. ADV without liver bypass seems to have a more favorable prognosis if it is not associated with other malformations.

Fetal intra-abdominal umbilical vein varix: what is the clinical significance?

OBJECTIVE

To assess the clinical significance of fetal intra-abdominal umbilical vein (FIUV) varix.

METHODS

We reviewed all cases of FIUV varix diagnosed in a university hospital from 1994 to 2003 and searched the English literature for cases of prenatal diagnosis of FIUV varix. The FIUV was considered dilated when the measurements were above 2 SD of the mean for gestational age. Cases reported in the literature were included if they met the diagnostic criteria for FIUV varix.

RESULTS

Between 1994 and 2003, 13 fetuses were diagnosed in our hospital as having FIUV varix. Review of the literature revealed an additional 80 cases. Fetal outcome was available for analysis in 91 cases. Additional sonographic abnormalities were detected prenatally in 29 cases (31.9%), most commonly anomalies of the cardiovascular system (including structural and functional abnormalities), hydropic features and anemia. There were nine (9.9%) cases of chromosomal abnormalities. All except one had associated sonographic abnormalities. There were 12 (13%) perinatal losses. Only 54 cases (59.3%) of fetuses with FIUV varix had a normal obstetric outcome. In the 62 cases with isolated FIUV varix, there were five unexplained intrauterine deaths (8.1%) occurring between 29 and 38 weeks of gestation. The incidence of complications, which included intrauterine death, thrombosis of the umbilical vein and abnormal antenatal cardiotocogram, were significantly higher (P = 0.01, Fisher's exact test) if the diagnosis of FIUV varix was made before 26 weeks.

CONCLUSIONS

FIUV varix is associated with a high incidence of fetal anomalies and obstetric complications. Detailed sonography is necessary to exclude fetal anomalies. Karyotyping should be offered when additional fetal abnormalities are detected. Intensive surveillance including color Doppler ultrasound should be started from the moment of diagnosis until delivery, especially in those cases presenting early in pregnancy.

Prenatal diagnosis of umbilicoportosystemic shunts: report of 11 cases and review of the literature

OBJECTIVE

The objective of our study was to classify, understand, and illustrate abnormalities of the embryologic development of the umbilical vein and the portal system resulting in umbilicoportosystemic shunts. According to our data and a review of the literature, we propose an anatomic, biometric, and hemodynamic assessment of umbilicoportosystemic shunts.

CONCLUSION

Umbilicoportosystemic shunts encompass different congenital vascular abnormalities that should be recognized because they may interfere with fetal growth and circulation.

Anomalies of the Fetal Venous System: A Report of 26 Cases and Review of the Literature

OBJECTIVE

To evaluate sonographic appearance, natural history, and neonatal outcome of fetal venous anomalies.

METHODS

We performed an observational study, including all fetuses affected by abnormalities of the venous system diagnosed by ultrasound during the prenatal period.

RESULTS

26 fetuses were identified. Other malformations were present in 5 cases (19.2%), 1 fetus had trisomy 21, and 1 fetus had intrauterine growth retardation (IUGR). Twenty-five pregnancies ended in liveborn infants, and there was 1 case of unexplained intrauterine death in the fetus with IUGR affected by varix of the umbilical vein.

CONCLUSIONS

Fetal venous anomalies are very rare and may be associated with fetal malformations or IUGR. Conservative management appears to be an adequate medical practice in the absence of other fetal problems, but in the presence of a varix of the umbilical vein, serial follow-up scans are needed to exclude the onset of hydrops or thrombosis of the varix.

Fetal intra-abdominal umbilical vein dilatation associated with notching in umbilical artery

INTRODUCTION

Dilatation of the fetal intra-abdominal umbilical vein is a rare entity. It is unclear whether prenatally diagnosed umbilical vein dilatation is associated with an increased risk of fetal anomalies or poor perinatal outcome. Umbilical artery waveform notching may be a predictor of cord abnormalities. It seems reasonable following the baby closely after the diagnosis of both conditions.

CASE REPORT AND DISCUSSION

We present here a new case diagnosed by ultrasonography at 30 weeks of gestation with normal fetal outcome and discuss the clinical features and the management of these rare abnormalities.

Three-dimensional color power imaging of the fetal hepatic circulation

OBJECTIVE

The purpose of this study was to describe the use of three-dimensional power Doppler ultrasonography to identify vascular congenital anomalies of fetal portosystemic and umbilical venous systems.

STUDY DESIGN

In a prospective study, the hepatic and umbilical venous systems were examined in 390 fetuses with two-dimensional ultrasonography, color, and spectral Doppler imaging. Fetuses suspected to have anomalies of the portal system and ductus venosus were additionally examined with three-dimensional power Doppler ultrasonography.

RESULTS

Vascular anomalies were identified in 8 fetuses (absent ductus venosus, n=4; direct connection between the umbilical vein and the right atrium, n=2; and direct connection between the umbilical vein and the inferior vena cava, n=2) out of the 310 in which the venous system could be adequately imaged (prevalence=2.6%). Three-dimensional power Doppler imaging showed the course of the umbilical vein, its relationship to the portosystemic circulation, and whether a ductus venosus was present.

CONCLUSION

Three-dimensional power Doppler ultrasonography can be used to image normal fetal hepatic and portal circulation, as well as identify anomalies of the fetal portosystemic and umbilical venous systems.

Abnormalities of the umbilico-portal venous system in Down syndrome: a report of two new patients

Congenital anomalies of the umbilical and portal venous system are rare vascular malformations which are often associated with anomalies of the heart and gastrointestinal tract. Association with chromosomal disorders has been sporadically reported. We now report on two patients with trisomy 21 and congenital anomalies of the umbilico-portal system. A male fetus showed absence of the intrahepatic portal vein (PV) and ductus venosus with a direct communication between portal sinus and inferior vena cava exhibiting an umbilicosystemic total shunt during the fetal life and a portosystemic total shunt after birth. A female infant showed absence of the intrahepatic PV and a total portocaval shunt. Both patients also had heart defects. As previously documented in other reports, our cases demonstrated that this association may be causally-related to the chromosomal aberration. In addition, the umbilico-portal venous system abnormalities seems to be the most frequent congenital vascular malformation in Down syndrome. A presumptive pathogenetic mechanism could be a trisomy 21-related altered angiogenesis of the vitelloumbilical plexus.

Prenatal diagnosis of ductus venosus agenesis and its association with cytogenetic/congenital anomalies

OBJECTIVES

We present an observational study of 12 cases of anomalies of the umbilical and portal vein systems associated with absence of the ductus venosus (DV) diagnosed over the past 5 years. The hemodynamic implications of each pattern of umbilico-portal system anomalies associated with absence of the DV have been investigated, as well as the frequency and types of associated anomalies and their embryological origin.

METHODS

In all cases ultrasound, color Doppler, and cytogenetic investigations were performed.

RESULTS

Four main patterns of abnormal venous circulation were documented: (1). the umbilical vein (UV) bypasses the liver and drains into the right atrium directly or through a dilated coronary sinus (three cases); (2). the UV bypasses the liver, with an infrahepatic or suprahepatic connection directly to the inferior vena cava (IVC) (two cases); (3). the UV bypasses the liver and drains directly into the iliac or renal veins (four cases); and (4). the UV drains directly into the portal veins (three cases). Among seven cases with other associated anomalies (58%), there were three cases of Turner's and Noonan's syndromes. Two fetuses and two neonates died and there were two terminations of pregnancy (TOP).

CONCLUSIONS

In utero diagnosis of ultrasound patterns associated with DV anomalies is feasible. Fetal karyotyping should be considered, serial ultrasound examinations recommended and, in the presence of heart failure, delivery can be anticipated.

Agenesis of the ductus venosus that is associated with extrahepatic umbilical vein drainage: prenatal features and clinical outcome

OBJECTIVE

We sought to study the clinical and ultrasonographic findings and outcomes of fetuses with ductus venosus agenesis as the result of extrahepatic umbilical vein drainage.

STUDY DESIGN

This was an observational study of 12 fetuses who were diagnosed with these anomalies between 1995 and 2001.

RESULTS

The umbilical vein drained either directly into the right atrium (n = 7 fetuses), the inferior vena cava (n = 3 fetuses), or the iliac vein (n = 2 fetuses). Combined cardiac output (n = 8 fetuses) was nearly 2-fold increased to 891 +/- 210 mL/kg per minute. Other relevant findings were (1) considerable umbilical vein enlargement (12/12 cases; range, 8-13 mm) with an accelerated (peak, 0.53 +/- 0.1 m/s), (2) pulsatile Doppler flow pattern within its intra-abdominal course, (3) cardiomegaly (12/12 fetuses), (4) secundum atrial septal defects (5/12 fetuses), (5) extracardiac anomalies (5/12 fetuses), (6) polyhydramnios (4/12 fetuses), and (7) progressive heart failure (3/12 fetuses). Two fetuses died: 1 death was unexplained at 29 weeks of gestation; the other death from hydrops occurred after delivery at 32 weeks of gestation. So far, none of the survivors have had other long-term sequelae that were related to ductus venosus agenesis.

CONCLUSION

Careful assessment of the umbilical venous return and the ductus venosus should be part of the routine evaluation of every fetus with heart failure and polyhydramnios.

The human fetal venous system: normal embryologic, anatomic, and physiologic characteristics and developmental abnormalities

OBJECTIVE

The introduction of high-resolution ultrasonography combined with color-coded Doppler imaging offered a breakthrough in the evaluation of the human fetal venous system, considerably enhancing our understanding of fetal venous circulation in normal physiologic conditions, as well as providing us the ability to study circulatory changes in abnormal circumstances. The purpose of this study was to describe the normal anatomic development and complex of anomalies of the human fetal venous system and to review recently published series of these anomalies.

METHODS

Normal embryologic and anatomic development is described. An English language literature search of recent MEDLINE listings was performed to glean data from recently published series reporting prenatal diagnosis of the various anomalies and their associated malformations.

RESULTS

Anomalies of the human fetal venous system occur sporadically, often associated with cardiac or other malformations. The pathophysiologic mechanisms leading to abnormal in utero development of the human venous system remain largely undetermined. On the basis of the type of vein involved, embryologic precursor, and etiologic correlation (primary or secondary), classification into 4 major groups is described.

CONCLUSIONS

Prenatal evaluation of fetuses found to have anomalies of the venous system should include a careful search for cardiac anomalies, including pulmonary venous drainage, and a detailed anatomic survey of the umbilical, portal, hepatic, and ductal systems to determine aberrant communication and, if possible, to discover clues to systemic diseases or thromboembolic phenomena.

Absence of the ductus venosus: report of 10 new cases and review of the literature

OBJECTIVE

To assess the clinical significance of the absence of the ductus venosus.

DESIGN

A retrospective study with a review of the literature.

METHODS

The archives of our ultrasound laboratory and the English literature were searched for cases with a prenatal diagnosis of absence of the fetal ductus venosus.

RESULTS

Between 1985 and 2000, 10 fetuses were diagnosed in our center as having absence of the ductus venosus. The review of the literature revealed 23 cases. Three main patterns of abnormal venous circulation were documented: (1) umbilical vein bypassing the liver and connecting directly to the right atrium (46%); (2) umbilical vein bypassing the liver and connecting to the inferior vena cava mostly through one of the iliac veins (25%); (3) umbilical vein connecting to the portal circulation without giving rise to the ductus venosus (21%). Major anomalies, including chromosomal aberrations, were found in 8/33 (24%) cases. Hydrops developed in 11/33 (33%) cases. Twenty fetuses with isolated absence of the ductus venosus were delivered, and 5 (20%) died. The portal vein was found to be absent in half of the infants examined after birth.

CONCLUSIONS

Our results and the review of literature suggest that absence of the ductus venosus is associated with a high incidence of fetal anomalies and adverse outcomes, including associated malformations, chromosomal aberrations, in utero heart failure and absence of the portal vein. Heart failure and absence of the portal vein seem particularly frequent when absence of the ductus venosus is associated with a connection of the umbilical vein to either the inferior vena cava or the right atrium.

Abnormalities of the fetal central veins and umbilico-portal system: prenatal ultrasonographic diagnosis and proposed classification

OBJECTIVES

Anomalies of the fetal venous system are poorly documented and their pathogenesis is not well understood. The present study was undertaken to review the spectrum of fetal central veins and umbilico-portal system anomalies, and to propose a classification system.

METHODS

A 7-year restrospective survey was conducted.

RESULTS

Nineteen fetuses showed abnormal connection between central veins and the fetal heart. Three fetuses showed abnormal connections of the cardinal veins, two of which had interruption of the inferior vena cava, and one had isolated persistent left superior vena cava. Anomalies of pulmonary veins were seen in four fetuses: in two with asplenia syndrome, a vertical confluent pulmonary artery was observed. In a further two cases total anomalous pulmonary venous connections were found. Abnormalities of the umbilical vein (UV) were seen in 10 cases; seven had persistent right UV, and three had a spectrum of anomalies: One had abnormal connections of the UV to the left iliac vein associated with agenesis of the ductus venosus (DV) and hydrops fetalis. One case showed in utero occlusion of the DV by echogenic foci that resulted in a persistent left proximal UV and porto-systemic shunt. One case had obliteration of the DV secondary to in utero fetal hepatic fibrosis. Abnormalities of the vitelline veins or portal system were demonstrated in two cases. One had a left porto-systemic shunt which resolved spontaneously at 3 months of age, and one had secondary partial occlusion of the left portal system with liver echogenicities and direct communication of the UV with the right atrium. None of the 19 cases had an abnormal karyotype or evidence of in utero infection.

CONCLUSIONS

Detection of various fetal vein anomalies in utero is feasible. The anomalies vary according to embryologic precursors or etiology. Two major mechanisms seem to be involved in the genesis of fetal vein anomalies: in most cases primary maldevelopment of the venous system occurs, while in the minority secondary anomalies from possible thromboembolic events or systemic disease may play a role.

Prenatal diagnosis of intrahepatic communications of the umbilical vein with atypical arteries (A-V fistulae) in two cases of trisomy 21 using color Doppler ultrasound

We report on two cases of the prenatal diagnosis of arterio-venous communication between the intra-abdominal umbilical vein and atypical arteries. The diagnosis was made by color and spectral Doppler and 'color power angiography'. Both cases presented with hydrops fetalis, one at 14 and the other at 31 weeks of gestation. In the first case, color Doppler demonstrated an atypical arterial vessel connecting the umbilical vein with the aorta; the ductus venosus was patent. Echocardiography showed a so-called atrioventricular canal. In the second case, a complex intrahepatic vascular malformation was found. Color Doppler demonstrated communications between the umbilical vein and the hepatic artery and an atypical artery; the ductus venosus was patent. In the latter case polyhydramnios, duodenal atresia and macroglossia were additionally detected. In both cases, fetal karyotyping revealed trisomy 21. The first case resulted in a missed abortion, the second in a stillbirth. All findings were confirmed on autopsy. Of interest is that both fetuses were affected with trisomy 21. The increasing use of color Doppler in prenatal diagnosis, especially in hemodynamically compromised fetuses, will help to determine the actual incidence of complex vascular malformations of the umbilical vein and to elucidate the impact of such malformations on fetal outcome.

Agenesis of the ductus venosus and its correlation to hydrops fetalis

Absence of the ductus venosus is a rare vascular anomaly. We report a late onset of a hydrops fetalis seen in a fetus at 34 completed weeks of gestation. A persistence of the cranial parts of the left and right umbilical veins and of the paired cranial vitelline veins with an absent ductus venosus led to a bilateral hydrothorax, ascites and skin-edema. Postnatally the hydrops resolved within 7 days most probably due to the change from the fetal to the adult circulation. The abnormal venous system was confirmed by angiography. Agenesis of the ductus venosus can manifest in two different morphologic patterns: The umbilical vein drains exclusively into the left branch of the intrahepatic portal vein or the umbilical vein drains into the inferior vena cava or directly into the right atrium by-passing the liver completely. In both patterns, the preferential direction of the flow towards the foramen ovale is not present. While the first pattern leads to hyperperfusion of the liver parenchyma, the latter would result in reduced perfusion and oxygenation. Our findings suggest that agenesis of ductus venosus might induce hydrops fetalis. We conclude, that in every case of hydrops fetalis the venous system should be evaluated by ultrasonography prenatally and/or immediately postnatally.

Fetal schistocytic hemolytic anemia and umbilical vein varix

A rare case of schistocytic hemolytic anemia presenting in a fetus secondary to a varix of the intra-abdominal umbilical vein is reported. A patient was referred to our hospital at 32 weeks of gestation because of an abnormal hypoechoic finding in the fetal liver. Prenatal ultrasound showed turbulent flow through a 12-mm diameter dilatation of the fetal intra-abdominal umbilical vein consistent with a varix. Cardiomegaly also was noted. At birth, the 1098-g, growth-retarded, male neonate was in severe congestive heart failure secondary to anemia as the initial hemoglobin was 5 g/dL. Additional evaluation found the anemia to be secondary to schistocytic hemolysis. After the neonate received a transfusion of packed erythrocytes and supportive care, the anemia quickly resolved, and he was discharged to home doing well after a 6-week stay in the neonatal intensive care unit. Prompt recognition of the varix prenatally and thorough evaluation of the newborn postnatally led to appropriate diagnosis and treatment.

Prenatal diagnosis of abnormalities of the fetal venous system

OBJECTIVE

To present our experience in the prenatal diagnosis of anomalies of fetal veins using high-resolution color Doppler ultrasound.

DESIGN

An observational study of 16 fetuses with abnormalities of the umbilical, portal, hepatic and caval venous system being diagnosed at the Division of Prenatal Diagnosis and Therapy (Bonn, Germany) over the past 5 years. The abnormality of the venous system, the underlying embryologic disorder and the outcome of the pregnancy are presented and compared with the literature.

RESULTS

In group A, eight fetuses had an abnormal course of the umbilical vein with a patent (n = 3) or absent (n = 5) ductus venosus. No portal veins and absent or abnormal hepatic veins were visualized by color Doppler sonography. Six fetuses (75%) did not have an associated malformation and have survived. Two pregnancies with fetal hydrops due to a small heart and to Turner's syndrome were terminated or ended in fetal demise. In group B, seven of eight fetuses with an abnormal caval system had a situs ambiguus or an atrial isomerism. A cardiac defect was detected in six cases (86%). These six pregnancies ended in four terminations of pregnancy and two infant deaths due to the severity of the congenital cardiac defect. One child with a normal heart and a child with an isolated abnormal course of the lower inferior vena cava are developing well.

CONCLUSIONS

In a targeted fetal scan the course of the umbilical vein, ductus venosus, the portal and hepatic veins and inferior vena cava should be carefully examined using color Doppler. Any suspicious finding should be followed by a detailed assessment of the specificity of this abnormality taking into consideration the embryologic development of the fetal venous system together with the associated malformations.

Prenatal sonographic diagnosis of persistent right umbilical vein with varix

Persistence of the right umbilical vein is variably associated with life-threatening malformations of the fetal genitourinary, gastrointestinal, cardiac, and skeletal systems. Varices of the intraabdominal umbilical vein, although not necessarily associated with other malformations, do seem to carry a risk of fetal mortality, especially if they are large or appear early during the pregnancy. We report the prenatal diagnosis of the rare combination of persistence and varix of the right umbilical vein in an otherwise healthy infant.

Prenatal ultrasonographic morphologic assessment of the umbilical cord: a review. Part II

Ultrasonographic assessment, although not always possible throughout the entire length of the umbilical cord, may assist in the diagnosis of congenital and functional anomalies of this structure. In such fashion, prenatal ultrasound may outline normal anatomy or alternatively depict various congenital abnormalities of the umbilical cord including: cysts; pseudocysts umbilical vein varix; persistent right umbilical vein; angiomyxomas; aneurysm (arterial or venous); single, hypoplastic or fused umbilical artery; hematomas (spontaneous or iatrogenic); velamentous insertion; vasa previa. The umbilical cord coiling index, an additional ultrasonographic morphologic feature, may identify patients at risk for adverse perinatal outcome. Conditions of potential fetal compromise due to umbilical cord compression including nuchal cords, true knots, occult prolapse, cord presentation, fetal grasping, and cord entanglement in monoamniotic twins, may be detected prenatally; and impaired umbilical flow can be confirmed with Doppler flow velocimetry. Ultrasound has been widely used to guide invasive diagnostic and therapeutic procedures involving access to umbilical circulation. We conclude that the review of current literature supports that precise prenatal ultrasonographic depiction of the morphology of the umbilical cord may enhance perinatal management.

Prenatal ultrasonographic morphologic assessment of the umbilical cord: a review. Part I

Our objective was to review current data pertaining to prenatal ultrasonographic morphology of the umbilical cord. To this goal we identified studies published in the English language regarding prenatal ultrasonographic morphology of this structure. The studies were obtained from a MEDLINE search from 1966 through May 1997; additional sources were identified through cross-referencing. All published reports, case studies, and articles regarding ultrasonographic morphology of the umbilical cord were reviewed. Data pertaining to Doppler flow velocimetry in association with umbilical cord structural anomalies and umbilical cord compression, were also included. Review of the literature supports that prenatal ultrasound may outline normal anatomy or alternatively depict various congenital abnormalities of the umbilical cord including: cysts; pseudocysts; umbilical vein varix; persistent right umbilical vein; hemangiomas; umbilical vessel aneurysm (arterial or venous); single, hypoplastic, or fused umbilical artery; hematomas (spontaneous or iatrogenic); velamentous insertion; and vasa previa. The umbilical cord coiling index, an additional ultrasonographic morphologic feature may identify patients at risk for adverse perinatal outcome. Conditions of potential fetal compromise due to umbilical cord compression including nuchal cords, true knots, occult prolapse, cord presentation, fetal grasping, and cord entanglement in monoamniotic twins, may be detected prenatally and impaired umbilical flow confirmed with Doppler flow velocimetry. Ultrasound has been widely applied to guide invasive diagnostic and therapeutic procedures involving access to umbilical circulation. In conclusion, precise prenatal ultrasonographic depiction of the morphology of the umbilical cord may enhance perinatal management.