A novel systematic approach to the evaluation of the fetal venous system

Value of foetal umbilical vein standardised blood flow volume in predicting weight gain in the third trimester: a prospective case-cohort study

Objective

This study aims to establish a prediction model of foetal umbilical vein standardised blood flow volume (sQuv) on estimated foetal weight (EFW) in the third trimester.

Methods

A case-cohort study involving 200 eligible normal foetuses was conducted at the Ultrasound Department of Longquanyi District of Maternity and Child Healthcare Hospital between June 1, 2020 and December 31, 2021. Ultrasound measurements were taken at two separate intervals to assess EFW and the rate of EFW (rEFW) [first: between 28 w and 33 w6d of gestational age (GA); second: after 4-6 weeks]. Umbilical vein blood flow volume (Quv) and sQuv (normalised with EFW) were calculated only during the initial measurement. Using general linear regression, a prediction model for EFW based on GA and sQuv was developed, with the gestational week employed as a calibration scalar and validated using linear regression cross-validation.

Results

In the third trimester, EFW exhibited significant correlations with GA, abdominal circumference (AC), head circumference (HC) and Quv (all ρ > 0.6, P < 0.001). Furthermore, the rEFW showed significant correlations with Quv and sQuv (all ρ > 0.6, P < 0.001). A linear regression equation was established using a general linear regression model: rEFW = 0.32689 × sQuv. Additionally, a foetal weight prediction model (EFW = -2,554.6770 + 0.9655 × sQuv + 129.6916 × GA) was established using sQuv. The above two formulas were cross-validated by intra-group linear regression and proved to be of good efficacy.

Conclusions

In the third trimester, EFW displayed significant correlations with GA, AC, HC and Quv. Additionally, the rEFW exhibited significant correlations with Quv and sQuv. The sQuv during the third trimester has predictive value for foetal weight, serving as an early warning indicator.

Persistent Left Superior Vena Cava: Why is Prenatal Diagnosis Important?

ObjectiveTo investigate fetal anomalies and pregnancy outcomes in pregnancies with persistent left superior vena cava (PLSVC) to provide assistance in prenatal counseling.MethodsCases diagnosed with PLSVC between January 2015 and January 2020 were obtained from the hospital's electronic system and were analyzed retrospectively.ResultsTwenty-seven cases were analyzed. The prevalence of PLSVC among congenital heart diseases (CHD) was 6.9%. Conotruncal anomalies and renal anomalies were the most common accompanying cardiac and extracardiac anomalies, respectively. Chromosomal abnormality was detected in one fetus.In the postpartum period coarctation of aorta (CoA) was found in one fetus.ConclusionsWhen PLSVC is detected during prenatal ultrasonography, fetal anatomy should be carefully examined because of the anomalies that may accompany it. Prenatal genetic counseling should be given especially to cases with additional anomalies. In isolated cases, cardiac anatomy should be evaluated with repeated echocardiography because of the risk of CoA.

Ultrasound Pitfalls in a Complex Fetal Cardiac Malformation—Case Report of a New Arteriovenous Central Communication

Cardiac and cardiovascular malformations are of real interest in terms of definition, epidemiology, and means of early diagnosis by imaging. Although ultrasound examination reaches exceptional performance nowadays, unusual pathologies are still exposed to the risk of either incorrect acquired image or misinterpretation by the specialist in a routine scan. Herein, we present a case of a 20-week-old fetus (from an apparently low-risk pregnancy) with complex cardiac and vascular abnormalities, including an arteriovenous malformation along with ventricular septal defect, ductal coarctation of the aorta, aneurysm of a brachiocephalic vein, and dilation of the entire neck and upper mediastinum venous system, and the limitations that were encountered in the process of diagnosis and management of the case.

Fetal-TAPSE for Surveillance of Cardiac Function in Growth-Restricted Fetuses With a Portosystemic Shunt

OBJECTIVES

Congenital portosystemic shunt (CPSS) in a growth-restricted fetus may lead to cardiac overload and ultimately hemodynamic imbalance. The aim of the study was to describe the application of tricuspid annular plane systolic excursion (TAPSE) for surveillance of cardiac function in growth-restricted fetuses diagnosed with CPSS.

METHODS

The study group consisted of 7 fetuses with growth restriction diagnosed with CPSS between 2018 and 2020. Patients were followed longitudinally every 2 weeks. Sonographic fetal-TAPSE (f-TAPSE) was performed every 2 weeks. At each visit, the following parameters were recorded: estimated fetal weight, biophysical profile, nonstress test, Doppler flow indices, and fetal cardiothoracic index. Postnatal laboratory and imaging tests were retrieved from the medical files.

RESULTS

Mean gestational age at diagnosis of CPSS was 32 + 1 weeks. Cardiomegaly was observed in all cases. All portosystemic shunts were classified as intrahepatic. Values of f-TAPSE were above the 95th percentile in 6/7 fetuses at presentation and throughout follow-up. Gestational age at delivery ranged between 36 + 5 and 38 + 5 weeks. Postnatally, spontaneous closure of the shunt was noted in 2 infants. Transient hyperammonemia was diagnosed in 2 neonates, with no signs of the characteristic complication.

CONCLUSIONS

In growth-restricted fetuses diagnosed concomitantly with CPSS, f-TAPSE offers a practical sonographic tool for assessment of cardiac function and may serve as an additional clinical marker for follow-up. The appearance of cardiomegaly in growth-restricted fetuses should prompt a dedicated sonographic evaluation of the fetal portal system.

Ultrasonographic evaluation of umbilical structures in Holstein calves: A comparison between healthy calves and calves affected by umbilical disorders

The aim of this study was to evaluate, during the first 4 wk of life, the involution of umbilical structures in clinically healthy calves and in calves affected by umbilical disorders, in both B-mode and color Doppler ultrasonography. The present study was carried out on 63 Holstein Friesian calves, divided into 3 different groups: group H (clinically healthy, n = 17), group A, (affected by omphaloarteritis, n = 24), and group V (affected by omphalophlebitis, n = 22). B-mode ultrasonography was performed at weekly intervals, using a portable device (LOGIQ Book XP, GE Healthcare, Little Chalfont, UK) and a linear multifrequency 7 to 10 MHz probe. In addition to the ultrasound examinations, the umbilicus of the calves was also evaluated using a color Doppler. The extra-abdominal as well as the intra-abdominal hemodynamics within the umbilical structures were evaluated using 3 different ranges of speed-flow detections (23, 14, and 7 cm/s). In healthy calves, as the age increased, the umbilical structures decreased in size and their ultrasonographic identification became more difficult. Conversely, in affected calves the umbilical structures did not show the same progressive reduction of external diameters and areas, but had an irregular trend of regression. Also the color Doppler ultrasonography showed a significant difference in frequency and percentage of speed-flow in the early days of examination between the 3 groups, with the most reliable results detected from the umbilical arteries. In our experimental study, omphaloarteritis could be detected at the d 1 color Doppler exam, with a 100% specificity and a 100% positive predictive value.

Color and power Doppler combined with Fetal Intelligent Navigation Echocardiography (FINE) to evaluate the fetal heart

OBJECTIVE

To evaluate the performance of color and bidirectional power Doppler ultrasound combined with Fetal Intelligent Navigation Echocardiography (FINE) in examining the fetal heart.

METHODS

A prospective cohort study was conducted of fetuses in the second and third trimesters with a normal heart or with congenital heart disease (CHD). One or more spatiotemporal image correlation (STIC) volume datasets, combined with color or bidirectional power Doppler (S-flow) imaging, were acquired in the apical four-chamber view. Each successfully obtained STIC volume was evaluated by STICLoop™ to determine its appropriateness before applying the FINE method. Visualization rates for standard fetal echocardiography views using diagnostic planes and/or Virtual Intelligent Sonographer Assistance (VIS-Assistance®) were calculated for grayscale (removal of Doppler signal), color Doppler and S-flow Doppler. In four cases with CHD (one case each of tetralogy of Fallot, hypoplastic left heart and coarctation of the aorta, interrupted inferior vena cava with azygos vein continuation and asplenia, and coarctation of the aorta with tricuspid regurgitation and hydrops), the diagnostic potential of this new technology was presented.

RESULTS

A total of 169 STIC volume datasets of the normal fetal heart (color Doppler, n = 78; S-flow Doppler, n = 91) were obtained from 37 patients. Only a single STIC volume of color Doppler and/or a single volume of S-flow Doppler per patient were analyzed using FINE. Therefore, 60 STIC volumes (color Doppler, n = 27; S-flow Doppler, n = 33) comprised the final study group. Median gestational age at sonographic examination was 23 (interquartile range, 21-27.5) weeks. Color Doppler FINE generated nine fetal echocardiography views (grayscale) using (1) diagnostic planes in 73-100% of cases, (2) VIS-Assistance in 100% of cases, and (3) a combination of diagnostic planes and/or VIS-Assistance in 100% of cases. The rate of generating successfully eight fetal echocardiography views with appropriate color and S-flow Doppler information was 89-100% and 91-100% of cases, respectively, using a combination of diagnostic planes and/or VIS-Assistance. However, the success rate for the ninth echocardiography view (i.e. superior and inferior venae cavae) was 33% and 30% for color and S-flow Doppler, respectively. In all four cases of CHD, color Doppler FINE demonstrated evidence of abnormal fetal cardiac anatomy and/or hemodynamic flow.

CONCLUSIONS

The FINE method applied to STIC volumes of normal fetal hearts acquired with color or bidirectional power Doppler information can generate successfully eight to nine standard fetal echocardiography views (via grayscale, color Doppler or power Doppler) in the second and third trimesters. In cases of CHD, color Doppler FINE demonstrates successfully abnormal anatomy and/or Doppler flow characteristics. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Azygos Vein Z Scores in Healthy Fetuses and Fetuses With Venous Malformations Related to the Azygos Vein

OBJECTIVES

To establish fetal azygos vein and descending aorta sonographic Z score formulas based on femur length and gestational age and to determine the value of azygos vein diameter variation for potential use in the diagnosis of fetal venous malformations related to the azygos vein.

METHODS

A total of 452 healthy singleton fetuses and 25 fetuses with venous malformations related to the azygos vein underwent prenatal sonography in this retrospective study. Azygos vein and descending aorta diameters were measured offline after spatiotemporal image correlation volume acquisition. Normal azygos vein and descending aorta Z score formulas were constructed for these measurements based on femur length by performing standard regression analysis followed by weighted regression of absolute residual values. The azygos vein-to-descending aorta ratio was calculated. Three parameters were compared between venous malformations related to the azygos vein and healthy fetuses.

RESULTS

Azygos vein and descending aorta Z score formulas were constructed. Both showed a positive linear correlation with femur length (r = 0.79 and 0.90, respectively; P < .01) and gestational age (r = 0.79 and 0.91; P < .01). The azygos vein Z scores and azygos vein-to-descending aorta ratios of fetuses with malformations were significantly higher than those of healthy fetuses (P < .01). In the abnormal group, 96.0% of azygos vein Z scores (24 of 25) were greater than ±2, and 96.0% of azygos vein-to-descending aorta ratios (24 of 25) were greater than the 95% confidence interval.

CONCLUSIONS

The azygos vein Z score formulas we developed can provide a quantitative basis for prenatal screening of venous malformations related to the azygos vein. Azygos vein dilatation and an abnormal azygos vein-to-descending aorta ratio may contribute to increasing the recognition of venous malformations involving the azygos vein.

Intrathymic and other anomalous courses of the left brachiocephalic vein in the fetus

OBJECTIVE

The left brachiocephalic vein (LBCV), or innominate vein, connects the left jugular vein to the right superior vena cava. Its course is posterior to the thymus and directly anterior and superior to the aortic arch. Pediatric and adult cardiology studies have reported on the subaortic or retrotracheal courses of the LBCV and the presence of double LBCV. We observed recently in the fetus that the LBCV may have a course through the thymus (intrathymic) or be absent in the presence of a left superior vena cava. The aim of this study was to report the prevalence of isolated intrathymic and absent LBCV in normal fetuses undergoing second-trimester ultrasound screening, as well as the prevalence of other courses in association with cardiac anomalies.

METHODS

In the prospective part of this study, consecutive second-trimester ultrasound examinations were evaluated to assess the presence and course of the fetal LBCV. In the retrospective case-control part of this study, the databases of two fetal medicine centers were reviewed for cardiac anomalies and the pattern and prevalence of anomalous courses of the LBCV were reported.

RESULTS

One thousand four hundred and eighteen consecutive fetuses were examined prospectively. An intrathymic course of the LBCV with a typical bent shape was found in 1.76% (1 : 57) of cases and the absence of a LBCV in association with a persistent left superior vena cava (LSVC) was found in 0.28% (1 : 350). All fetuses with an isolated intrathymic course or absence of the LBCV had a normal outcome. Over a period of 4.5 years, a total of 1544 fetuses with cardiac malformations were reviewed at two centers. Among these, an anomalous course of the LBCV was noted in eight (0.5%) cases: six subaortic, one retrotracheal and one double LBCV.

CONCLUSION

An intrathymic LBCV is a common condition and appears to be a normal variant in the fetus. The prevalence of a LSVC in our screening population was similar to that reported in previous studies. Anomalous courses of the LBCV are seen occasionally in cases with cardiac malformation. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Systematic examination of the fetal abdominal precordial veins: a cohort study

OBJECTIVES

Examination of the fetal venous system is a necessary part of complete fetal organ scanning to confirm landmark anatomy, such as the ductus venosus and course of the umbilical veins, and, whenever cardiovascular anomalies are identified, to exclude associated anomalous development of the fetal veins. We aimed to develop a protocol for systematic examination of the fetal venous system during midtrimester targeted organ scanning.

METHODS

We included low-risk women with a singleton fetus presenting between January 2011 and June 2013 to our center for routine midtrimester (20-24 weeks) targeted organ scanning. Imaging of the venous system was added to the booked scan and comprised two-dimensional color Doppler scanning of the fetal abdomen in three discrete planes, two transverse and one longitudinal. The more caudal plane was obtained in a ventral or lateral transverse abdominal plane to image the umbilical vein, left portal vein, portal sinus, anterior right portal vein, posterior right portal vein, main portal vein and splenic vein and artery. Moving cephalad, a ventral or lateral transverse plane was obtained to image the right, middle and left hepatic veins and inferior vena cava (IVC). Finally, a longitudinal anteroposterior plane showed the umbilical vein, ductus venosus, IVC and left hepatic vein. In some cases the pulsed Doppler waveform of a given target vessel was also examined. Three-dimensional/4D ultrasound was applied as necessary, when anomalous cases were encountered.

RESULTS

We examined 1810 women. Their body mass index ranged from 19 to 40 (mean, 24.7). In 38 (2.1%) women, the target anatomy was not visualized satisfactorily owing to maternal body habitus. A T-shaped configuration of the portal system vessels was observed in 63% of cases, an X-shaped configuration in 25% and an H-shaped configuration in 12%. During the study period, 24 congenital anomalies of the precordial venous system were diagnosed: nine cases of persistent right umbilical vein, seven of agenesis of the ductus venosus, five of anomalous portal venous drainage and three of interrupted IVC with azygos continuation.

CONCLUSIONS

Examination of the fetal venous system is feasible with the application of three abdominal planes. While a venous system scan is not practicable as part of a screening-level examination, mastery of the normal anatomy is an essential part of the professional knowledge base, in order to provide ready and complete scanning of the system in cases of suspected anomalies or disordered cardiac function.