Absence of Ductus Venosus: A Comparison of 2 Distinctive Fetal Autopsy Cases and Embryologic Perspectives.

In fetal circulation, oxygenated blood from the placenta flows through the umbilical vein into the ductus venosus (DV), then enters the inferior vena cava, and subsequently reaches the right atrium of the heart. The DV serves as a shunt, allowing this oxygen-rich blood to bypass the liver. The absence of the DV (ADV), also known as agenesis of the DV, is a rare congenital anomaly. Without a DV, blood from the umbilical vein must follow alternative routes to the heart. In ADV cases, blood from the umbilical vein must follow 1 of 2 primary drainage patterns: either an extrahepatic shunt or an intrahepatic shunt. This report details the antenatal ultrasound and postmortem findings of 2 fetuses diagnosed with ADV by prenatal imaging studies. The first case involved a fetus with a persistent right umbilical vein connected directly to the suprahepatic IVC, accompanied by early obliteration of the left umbilical vein and true agenesis of the DV. This fetus also had additional congenital anomalies. In contrast, the second case involved a fetus with a normal left umbilical vein that entered the liver. However, despite an ultrasound diagnosis of "absence" of the DV, a DV was present, though markedly hypoplastic and probably minimally functional or non-functional. In this case, blood from the umbilical vein likely followed an alternate intrahepatic route through the portal and hepatic veins, before reaching the heart (intrahepatic shunt). These contrasting cases emphasize the heterogeneity of vascular anomalies and embryologic origins captured by the term "ADV." Additionally, the terminology of "absence" or "agenesis" may be misleading in some purported ADV cases. Specifically, in the second case, the DV was not absent; it was markedly hypoplastic instead. This also appears to be the first reported case of a hypoplastic DV in a fetus. Both cases underscore the importance of effective collaboration and clear communication between maternal-fetal medicine specialists and pathologists.

Persistent Right Umbilical Vein in Association With Single Umbilical Artery: A Case Report and Review of Literature.

Persistent right umbilical vein (PRUV) and single umbilical artery (SUA) are developmental malformations of the vascular system. In isolation, these are not rare, but the presence of these two malformations together is not very common. When they are present together, there are increased chances of associated congenital anomalies, especially anomalies of the vascular system. So, when these two coexist, a detailed examination of all other organ systems, especially the cardiovascular system, should be conducted. The accurate evaluation of such vascular malformations during fetal life is needed to provide adequate antenatal counseling, the timing of delivery, and appropriate post-natal care. We report a case of a primigravida who was diagnosed with PRUV and SUA in the fifth month of gestation. In this article, we discuss this case's management with a literature review. The anomaly scan done at around 21 weeks revealed a two-vesseled umbilical cord with an SUA and PRUV. Apart from this, there were no other structural anomalies. The patient had preterm delivery at 35 weeks 5 days gestation period and delivered a 2.6 kg male baby.

Prenatal diagnosis of the persistent right umbilical vein, incidence and clinical significance.

Prenatal diagnosis of persistent right umbilical vein (PRUV) is important due to accompanying malformations. Pregnant women diagnosed with PRUV were analysed retrospectively. Intrahepatic PRUV was seen in 12 of 10.743 foetuses and its incidence was found to be 0.11%. The gestational week at the time of diagnosis was between 20 and 35 weeks. Six of the cases had additional abnormal sonographic findings (50%) and six cases (50%) were isolated. Major congenital malformations were seen in four (33.3%) foetuses, 75% of which were congenital heart disease (CHD). Genitourinary system anomaly accompanied in two cases (16.6%). Invasive diagnostic tests were applied to three pregnant women and the results were reported as normal karyotype. In PRUV cases, a detailed sonographic examination should be performed, especially the cardiovascular system. Although PRUV cases do not appear to be associated with chromosomal abnormalities, invasive diagnostic tests should be recommended in the presence of concomitant anomalies.Impact statementWhat is already known on this subject? The persistent right umbilical vein (PRUV) is a pathological vascular anomaly, in which the left umbilical vein regresses and the right umbilical vein remains open. PRUV can occur in an isolated form that represents its normal variant or be associated with other major or minor anomalies.What do the results of this study add? Additional abnormal sonographic findings were accompanied in 50% of PRUV, major anomaly was detected in 33.3% of them and cardiovascular abnormalities constituted 75% of foetuses with major anomalies.What are the implications of these findings for clinical practice and/or further research? The presence of concomitant anomalies in PRUV cases is not rare and detailed anatomy screening should be done. The most common accompanying abnormality is seen in the cardiovascular system, so foetuses with PRUV should be evaluated by foetal echocardiography.

Ultrasonic detection of fetal persistent right umbilical vein and incidence and significance of concomitant anomalies.

BACKGROUND: Persistent right umbilical vein (PRUV) is characterized by atresia of the left umbilical vein while the right umbilical vein remains open. Given the limited sample size of most studies, the incidence of PRUV and the status of concomitant anomalies may not be fully reflected. Thus, we studied the incidence of fetal PRUV and its concomitant anomalies on a larger scale using our hospital database. This study hoped to address the following questions: Does PRUV increase the risk of fetal anomalies? If the PRUV fetus also has a single umbilical artery (SUA), does the risk of fetal anomaly increase further? What is the positive predictive value of PRUV for fetal anomalies? METHODS: This retrospective study analyzed 756 cases of fetal PRUV at our hospital from January 2007 to April 2017. Prenatal ultrasound and color Doppler images were assessed. All PRUV fetuses underwent echocardiography and detailed ultrasound examinations of other systems. Newborn status was obtained via the database or by telephone follow-up. RESULTS: A total of 435,428 pregnant women underwent prenatal ultrasonography at 16-40 weeks, the incidence of fetal PRUV was 0.17%, and 102 fetuses (13.5%) developed other anomalies. Two complicated cases had trisomy 18. PRUV was associated with a higher incidence of fetal anomalies. When fetal anomalies were classified by body systems, PRUV was associated with a higher incidence of cardiovascular, nervous, urinary, skeletal, digestive, and respiratory system anomalies. The positive predictive values of a PRUV for any fetal anomalies and cardiovascular anomalies were 13.5% (95%CI, 11.2-16.2%) and 5.4% (95%CI, 4.0-7.3%), respectively. SUA further increases the risk of PRUV fetuses with other anomalies and cardiovascular anomalies. CONCLUSIONS: Detailed prenatal ultrasonography and echocardiography should be performed in fetuses with PRUV to rule out anomalies in other systems. When the PRUV is combined with SUA, echocardiography is particularly important. Fetuses with complicated PRUV should undergo chromosomal examination. Although isolated fetal PRUV prognosis is good, complicated PRUV prognosis depends on the type and severity of the concomitant anomalies.

Persistence of right umbilical vein: a singular case.

BACKGROUND: Persistent right umbilical vein (PRUV) is one of the most common prenatally detected venous anomaly. In the intrahepatic variant (I-PRUV) the right umbilical vein fuses with right portal vein and through the ductus venous drains into inferior vena cava, while in the uncommon extrahepatic variant (E-PRUV), the vein bypasses the liver completely. E-PRUV has a worse prognosis compared to I-PRUV, due either to severe hemodynamic effects or to the frequent association with other severe fetal malformations. CASE: Here we report a case of E-PRUV with good outcome. Prenatal fetal ultrasonography (US) performed at 33 weeks of gestation in 28-year old woman, highlights the presence of E-PRUV with right UV draining in inferior vena cava. In the male neonate born at 35 weeks of gestation by C-section, the Apgar Score was 95`- 1010 and no other associated malformations and hemodynamic decompensation were found. Postnatal abdominal US showed the presence of enlarged paraumbilical veins. CONCLUSIONS: The association of E-PRUV draining into the inferior vena cava with shunt through paraumbilical veins, could have preserved offspring by severe cardiac overload, positively affecting prognosis.

Prenatal diagnosis of persistent right umbilical vein - Incidence and clinical impact. A prospective study.

BACKGROUND: Persistent right umbilical vein (PRUV) is usually an isolated finding but it may be accompanied by other fetal malformations. AIMS: We aimed to determine the incidence of prenatally diagnosed PRUV in a referral population, assess the neonatal outcome and discuss the findings together with those from previous publications. MATERIALS AND METHODS: A total of 2360 women with low-risk singleton pregnancies were examined in the second and third trimesters. A transabdominal convex volume transducer was used. B-mode was applied in each patient. Scanning of the venous system included imaging of the target vessels with two-dimensional colour Doppler mapping. The diagnosis of PRUV was made in a transverse section of the fetal abdomen. Three-dimensional ultrasounds were performed as necessary, when anomalous cases were encountered. RESULTS: The incidence of PRUV in our population was 12/2360 = 0.5%, and it was higher than in other retrospective studies. In 75% (n = 9), PRUV was an isolated finding where delivery was uneventful and the postnatal outcome was favourable. In two cases PRUV was accompanied by omphalocele, and in one case by tetralogy of Fallot and single umbilical artery. CONCLUSIONS: PRUV is an uncommon prenatal finding. Screening for this anomaly can be easily performed in all pregnant patients. A diagnosis of PRUV should be followed by a thorough fetal morphology scan in order to exclude any other malformations, especially those of the cardiovascular system.

Persistent right umbilical vein: a study using serial sections of human embryos and fetuses.

Persistent right umbilical vein (PRUV) is a common anomaly of the venous system. Although candidates for future PRUV were expected to occur more frequently in earlier specimens, evaluation of serial horizontal sections from 58 embryos and fetuses of gestational age 5-7 weeks found that only two of these embryos and fetuses were candidates for anomalies. In a specimen, a degenerating right umbilical vein (UV) joined the thick left UV in a narrow peritoneal space between the liver and abdominal cavity, and in the other specimen, a degenerating left UV joined a thick right UV in the abdominal wall near the liver. In these two specimens, the UV drained into the normal, umbilical portion of the left liver. These results strongly suggested that, other than the usual PRUV draining into the right liver, another type of PRUV was likely to consist of the right UV draining into the left liver.

Demographic and perinatal outcome data of fetuses with SUA/PRUV.

AIM: Identify structural anomalies and adverse pregnancy outcomes accompanying single umbilical artery (SUA) and persistent right umbilical vein (PRUV) and to investigate whether SUA and PRUV are associated with chromosomal abnormalities and if these defects warrant invasive antenatal diagnosis. METHODS: We retrospectively analyzed pregnancies with an antenatal diagnosis of SUA/PRUV from the International Peace Maternity and Child Health Hospital (IPMCHH) database. Data of structural malformations, fetal karyotyping, and pregnancy outcomes were analyzed. RESULTS: Results revealed that 13.9 and 7% of SUA and PRUV cases, respectively, had malformations. Furthermore, 60% of the malformations accompanying SUA were isolated congenital heart disease (CHD), and 50% of the malformations accompanying PRUV were multiple malformations including CHD. All primarily diagnosed isolated PRUV (iPRUV) cases and 92.6% of primarily diagnosed iSUA cases had normal fetal echocardiography. Cases of iSUA and iPRUV with indications of invasive antenatal diagnosis showed no chromosomal abnormalities. The emergency cesarean section rate did not differ between the study population and the IPMCHH general population (p = .184). CONCLUSION: Patients of SUA and PRUV diagnosed in secondary hospitals should be referred to tertiary medical center for further ultrasonography. SUA and PRUV are not indicators for invasive antenatal diagnosis and selective cesarean section.

Persistent right umbilical vein: a study using serial sections of human embryos and fetuses / 대한해부학회지

Persistent right umbilical vein (PRUV) is a common anomaly of the venous system. Although candidates for future PRUV were expected to occur more frequently in earlier specimens, evaluation of serial horizontal sections from 58 embryos and fetuses of gestational age 5–7 weeks found that only two of these embryos and fetuses were candidates for anomalies. In a specimen, a degenerating right umbilical vein (UV) joined the thick left UV in a narrow peritoneal space between the liver and abdominal cavity, and in the other specimen, a degenerating left UV joined a thick right UV in the abdominal wall near the liver. In these two specimens, the UV drained into the normal, umbilical portion of the left liver. These results strongly suggested that, other than the usual PRUV draining into the right liver, another type of PRUV was likely to consist of the right UV draining into the left liver.

A retrospective single centre review of the incidence and prognostic significance of persistent foetal right umbilical vein.

The objective of our study was to appraise the incidence and significance of persistent right umbilical vein (PRUV), the most common foetal venous aberration. Based on a south Indian antenatal cohort, we identified 23 cases of PRUV amongst 20,452 foetuses of consecutive pregnancies, from 2009 to 2014, yielding an incidence of 1 in 889 total births (0.11%). The median maternal age was 24 (IQR, 22-26) years, and median gestational age at diagnosis was 23 (IQR, 22-24) weeks. Intrahepatic drainage of PRUV was seen in 91.3% cases. In three cases (13%), ductus venosus was absent. In 52.2% of the cases, additional major abnormalities were observed - predominantly cardiovascular (39.1%). The common minor marker was single umbilical artery (13%). The karyotype was found to be normal in six cases (26%) which underwent invasive testing. When associated anomalies were inconsequential or absent, the postnatal outcome was good, which reflected in 60.9% of our cases.

Intrahepatic Persistent Right Umbilical Vein and Associated Outcomes: A Systematic Review of the Literature.

The aim of this study was to provide a comprehensive review of the current data surrounding an intrahepatic persistent right umbilical vein in the fetus, including associated anomalies and outcomes, and to assist practitioners in counseling and management of affected pregnancies. We performed a MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Northern Light database search for articles reporting outcomes on prenatally diagnosed cases of a persistent right umbilical vein. Each article was independently reviewed for eligibility by the investigators. Thereafter, the data were extracted and validated independently by 3 investigators. A total of 322 articles were retrieved, and 16 were included in this systematic review. The overall prevalence of an intrahepatic persistent right umbilical vein was found to be 212 per 166,548 (0.13%). Of the 240 cases of an intrahepatic persistent right umbilical vein identified, 183 (76.3%) were isolated. The remaining cases had a coexisting abnormality, including 19 (7.9%) cardiac, 9 (3.8%) central nervous system, 15 (6.3%) genitourinary, 3 (1.3%) genetic, and 17 (7%) placental/cord (predominantly a single umbilical artery). In summary, a persistent right umbilical vein is commonly an isolated finding but may be associated with a coexisting cardiac defect in 8% of cases. Therefore, consideration should be given to fetal echocardiography in cases of a persistent right umbilical vein.