Three-vessel view of the fetal upper mediastinum: an easy means of detecting abnormalities of the ventricular outflow tracts and great arteries during obstetric screening

Diagnostic accuracy of ultrasound screening for fetal structural abnormalities during the first and second trimester of pregnancy in low-risk and unselected populations

BACKGROUND

Prenatal ultrasound is widely used to screen for structural anomalies before birth. While this is traditionally done in the second trimester, there is an increasing use of first-trimester ultrasound for early detection of lethal and certain severe structural anomalies.

OBJECTIVES

To evaluate the diagnostic accuracy of ultrasound in detecting fetal structural anomalies before 14 and 24 weeks' gestation in low-risk and unselected pregnant women and to compare the current two main prenatal screening approaches: a single second-trimester scan (single-stage screening) and a first- and second-trimester scan combined (two-stage screening) in terms of anomaly detection before 24 weeks' gestation.

SEARCH METHODS

We searched MEDLINE, EMBASE, Science Citation Index Expanded (Web of Science), Social Sciences Citation Index (Web of Science), Arts & Humanities Citation Index and Emerging Sources Citation Index (Web of Science) from 1 January 1997 to 22 July 2022. We limited our search to studies published after 1997 and excluded animal studies, reviews and case reports. No further restrictions were applied. We also screened reference lists and citing articles of each of the included studies.

SELECTION CRITERIA

Studies were eligible if they included low-risk or unselected pregnant women undergoing a first- and/or second-trimester fetal anomaly scan, conducted at 11 to 14 or 18 to 24 weeks' gestation, respectively. The reference standard was detection of anomalies at birth or postmortem.

DATA COLLECTION AND ANALYSIS

Two review authors independently undertook study selection, quality assessment (QUADAS-2), data extraction and evaluation of the certainty of evidence (GRADE approach). We used univariate random-effects logistic regression models for the meta-analysis of sensitivity and specificity.

MAIN RESULTS

Eighty-seven studies covering 7,057,859 fetuses (including 25,202 with structural anomalies) were included. No study was deemed low risk across all QUADAS-2 domains. Main methodological concerns included risk of bias in the reference standard domain and risk of partial verification. Applicability concerns were common in studies evaluating first-trimester scans and two-stage screening in terms of patient selection due to frequent recruitment from single tertiary centres without exclusion of referrals. We reported ultrasound accuracy for fetal structural anomalies overall, by severity, affected organ system and for 46 specific anomalies. Detection rates varied widely across categories, with the highest estimates of sensitivity for thoracic and abdominal wall anomalies and the lowest for gastrointestinal anomalies across all tests. The summary sensitivity of a first-trimester scan was 37.5% for detection of structural anomalies overall (95% confidence interval (CI) 31.1 to 44.3; low-certainty evidence) and 91.3% for lethal anomalies (95% CI 83.9 to 95.5; moderate-certainty evidence), with an overall specificity of 99.9% (95% CI 99.9 to 100; low-certainty evidence). Two-stage screening had a combined sensitivity of 83.8% (95% CI 74.7 to 90.1; low-certainty evidence), while single-stage screening had a sensitivity of 50.5% (95% CI 38.5 to 62.4; very low-certainty evidence). The specificity of two-stage screening was 99.9% (95% CI 99.7 to 100; low-certainty evidence) and for single-stage screening, it was 99.8% (95% CI 99.2 to 100; moderate-certainty evidence). Indirect comparisons suggested superiority of two-stage screening across all analyses regarding sensitivity, with no significant difference in specificity. However, the certainty of the evidence is very low due to the absence of direct comparisons.

AUTHORS' CONCLUSIONS

A first-trimester scan has the potential to detect lethal and certain severe anomalies with high accuracy before 14 weeks' gestation, despite its limited overall sensitivity. Conversely, two-stage screening shows high accuracy in detecting most fetal structural anomalies before 24 weeks' gestation with high sensitivity and specificity. In a hypothetical cohort of 100,000 fetuses, the first-trimester scan is expected to correctly identify 113 out of 124 fetuses with lethal anomalies (91.3%) and 665 out of 1776 fetuses with any anomaly (37.5%). However, 79 false-positive diagnoses are anticipated among 98,224 fetuses (0.08%). Two-stage screening is expected to correctly identify 1448 out of 1776 cases of structural anomalies overall (83.8%), with 118 false positives (0.1%). In contrast, single-stage screening is expected to correctly identify 896 out of 1776 cases before 24 weeks' gestation (50.5%), with 205 false-positive diagnoses (0.2%). This represents a difference of 592 fewer correct identifications and 88 more false positives compared to two-stage screening. However, it is crucial to acknowledge the uncertainty surrounding the additional benefits of two-stage versus single-stage screening, as there are no studies directly comparing them. Moreover, the evidence supporting the accuracy of first-trimester ultrasound and two-stage screening approaches primarily originates from studies conducted in single tertiary care facilities, which restricts the generalisability of the results of this meta-analysis to the broader population.

A deep learning framework for identifying and segmenting three vessels in fetal heart ultrasound images

BACKGROUND

Congenital heart disease (CHD) is one of the most common birth defects in the world. It is the leading cause of infant mortality, necessitating an early diagnosis for timely intervention. Prenatal screening using ultrasound is the primary method for CHD detection. However, its effectiveness is heavily reliant on the expertise of physicians, leading to subjective interpretations and potential underdiagnosis. Therefore, a method for automatic analysis of fetal cardiac ultrasound images is highly desired to assist an objective and effective CHD diagnosis.

METHOD

In this study, we propose a deep learning-based framework for the identification and segmentation of the three vessels-the pulmonary artery, aorta, and superior vena cava-in the ultrasound three vessel view (3VV) of the fetal heart. In the first stage of the framework, the object detection model Yolov5 is employed to identify the three vessels and localize the Region of Interest (ROI) within the original full-sized ultrasound images. Subsequently, a modified Deeplabv3 equipped with our novel AMFF (Attentional Multi-scale Feature Fusion) module is applied in the second stage to segment the three vessels within the cropped ROI images.

RESULTS

We evaluated our method with a dataset consisting of 511 fetal heart 3VV images. Compared to existing models, our framework exhibits superior performance in the segmentation of all the three vessels, demonstrating the Dice coefficients of 85.55%, 89.12%, and 77.54% for PA, Ao and SVC respectively.

CONCLUSIONS

Our experimental results show that our proposed framework can automatically and accurately detect and segment the three vessels in fetal heart 3VV images. This method has the potential to assist sonographers in enhancing the precision of vessel assessment during fetal heart examinations.

Prenatal Diagnosis of a Ductal-Dependent Branch Pulmonary Artery: Extra Vessels in the 3-Vessel and Trachea View

Obtaining a three-vessel (3V) and three-vessel and trachea (3VT) view from the fetal upper mediastinum is now considered to be part of standard imaging protocol for routine obstetric cardiac screening examinations. We report two fetal cases of an anomalous pulmonary artery origin, utilizing the standard 3V and 3VT views. Further imaging led to a rare diagnosis of bilateral ductus arteriosus with discontinuous branch pulmonary arteries in the absence of any other congenital heart defect. We briefly discuss the imaging features, differential diagnoses, and management of this rare entity.

Increased Pulmonary-Aortic Interspace in Fetal Right Aortic Arch: A Matched Case-Control Study

INTRODUCTION

The prenatal detection rate of a right aortic arch (RAA) has increased with the implementation of the three-vessel view (3VV) to the second-trimester anomaly scan formed by the pulmonary artery (PA), aorta (Ao), and superior vena cava (SVC). We examined the value of measuring the distance between PA and Ao in the 3VV in cases with an RAA.

METHODS

We conducted a case-control study in which fetuses with an isolated RAA were matched to 3 healthy controls. Using 3VV images, the distances between PA, Ao, and SVC were measured and the ratio between PA to Ao (PAAo) distance and Ao to SVC (AoSVC) distance was calculated.

RESULTS

Fifty-four RAA cases and 162 matched controls were included. The mean absolute distance PAAo was 3.1 mm in cases and 1.8 mm in controls (p < 0.001), and the mean PAAo/AoSVC ratio was 2.9 and 1.4, respectively (p < 0.001). The ROC curve of PAAo/AoSVC ratio showed a cut-off point of 1.9 with sensitivity and specificity over 87% for the diagnosis of RAA.

CONCLUSIONS

The pulmonary-aortic interspace and the PAAo/AoSVC ratio were significantly larger for RAA cases as compared to controls. If an increased pulmonary-aortic interspace is observed, a PAAo/AoSVC of ≥1.9 can be helpful in the diagnosis of an RAA.

3D printing of foetal vascular rings: feasibility and applicability

BACKGROUND

Vascular rings (VRs) exhibit complex and diverse forms that are difficult to conceptualize using traditional two-dimensional (2D) schematic. Inexperienced medical students and parents who lack a medical technology background face significant challenges in understanding VRs. The purpose of this research is to develop three-dimensional (3D) printing models of VRs to provide new technical imaging support for medical education and parental consultation.

METHODS

This study included 42 fetuses diagnosed as VRs. Foetal echocardiography, modeling and 3D printing were performed, and the dimensional accuracy of models was analyzed. The value of 3D printing in the teaching of VRs was analyzed based on comparing the test results before and after the teaching intervention of 48 medical students and the satisfaction survey. A brief survey was conducted to 40 parents to assess the value of the 3D printed model in prenatal consultations.

RESULTS

Forty models of VRs were successfully obtained, which reproduced the anatomical shape of the VRs space with high dimensional accuracy. No differences in the prelecture test results were noted between the 3D printing group and the 2D image group. After the lecture, the knowledge of both groups improved, but the postlecture score and the change in the prelecture versus postlecture score were greater in the 3D printing group, and the subjective satisfaction survey feedback in the 3D printing group was also better (P < 0.05). Similar results were observed from the parental questionnaire, the vast majority of parents have an enthusiastic and positive attitude towards the use of 3D printed models and suggest using them in future prenatal consultations.

CONCLUSIONS

Three-dimensional printing technology providing a new tool for effectively displaying different types of foetal VRs. This tool helps physicians and families understand the complex structure of foetal great vessels, positively impacting medical instruction and prenatal counselling.

Prenatal screening and diagnosis of pulmonary artery anomalies

Congenital pulmonary artery anomalies are rare. Their antenatal diagnosis requires good knowledge of fetal cardiac anatomy because their clinical presentation varies depending on the type and severity of the underlying lesion. Screening of these vascular anomalies can be straightforward in some cases because of significant associated consequences that are detected easily on ultrasound, while other anomalies have considerably less obvious features. There may be an associated genetic syndrome. The aim of this review was to define anomalies of the main pulmonary artery and its branches and to propose, through the identification of suspicious findings during routine antenatal heart examination, an optimal screening method for the pulmonary artery pathway. We propose that pulmonary artery anomalies can be classified antenatally into four types of disorder. Herein we describe 14 cases subgrouped accordingly as: anomalies of the pulmonary valvular region, with stenosis or atresia of the valve (n = 4); conotruncal abnormalities (n = 4); anomalies associated with abnormal origin or course of the pulmonary artery (n = 4); and anomalies associated with abnormal growth of the pulmonary artery and its branches (n = 2). We highlight the need to differentiate the three-vessel view from the three-vessel-and-trachea view when assessing a fetus with a congenital pulmonary artery anomaly. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The use of cardiac ultrasound imaging in first-trimester prenatal diagnosis of congenital heart diseases

This study aims to explore ultrasound (US) cardiac and echocardiographic features that may enable the early diagnosis of various major congenital heart diseases (CHDs). Focusing on providing useful US tools for this assessment, high resolution of US cardiac images of various CHDs, such as hypoplastic left heart syndrome, conotruncal anomalies, and univentricular heart, were evaluated. Results show that early US detection of most major CHDs is feasible during first-trimester ultrasonography cardiac evaluation. Concerns about safety issues, findings on early fetal cardiovascular hemodynamics, and cardiac lesions that can progress during the course of pregnancy were also discussed.

Prenatal Diagnosis of the Right Aortic Arch: Change in Detection Rate, the Status of Associated Anomalies, and Perinatal Outcomes in 137 Fetuses

To evaluate prenatal findings of the right aortic arch (RAA), associated cardiac, extracardiac, and genetic anomalies, its perinatal outcomes and the need for postnatal interventions in cases of isolated RAA with a view to facilitating appropriate counseling. This was a multicenter, cohort study, that was undertaken in two international major cardiac centers between 2009 and 2020. The study subjects were prenatally diagnosed RAA cases with and without other structural cardiac defects. A RAA was identified in 137 fetuses. There were 84 cases of isolated RAA. Associations with additional intracardiac malformations were found in 53 (38.7%) cases. An extracardiac anomaly was observed in 26/137 (18.9%) fetuses, 11/84 (13.0%) fetuses with isolated RAA, and 15/53 (28.3%) fetuses with an additional intracardiac anomaly. The incidence of extracardiac and chromosomal anomalies was significantly higher in cases of RAA with abnormal intracardiac anatomy (28.3-18.8%, respectively), compared with RAA with normal intracardiac anatomy (13.0-5.9%, respectively) (p < 0.05). 22q11.2 microdeletion was found higher in RAA with CHD (4/18 fetuses) than isolated RAA (2/24 fetuses) (22.2% vs. 8.3% respectively). ALSA was present in 19.3% of cases. ALSA was more frequently observed in cases of isolated RAA (23.6%), than in RAA with structural CHD (7.6%) (p < 0.05). The pregnancy was interrupted in six fetuses, and one died in utero. The mortality rate was higher in fetuses with intracardiac anomaly than RAA without cardiac anomaly (11/49 (22.4%) vs. 2/81 (2.4%). Vascular ring formation was revealed in 21/98 cases. The RAA caused symptoms of a vascular ring in only one patient (0.7%) requiring surgery in the follow-up. Overall survival after initial diagnosis in the total cohort was 85.4% with 38 of 53 (71%) RAA with CHD cases and 79 of 84 (94.0%) isolated RAA cases. Chromosomal and extracardiac anomalies are lower in isolated RAA but not negligible hence amniocentesis should be routinely offered in all cases. The requirement for postnatal intervention in the immediate neonatal period is remote, therefore delivery of these fetuses need not be undertaken at a cardiac or surgical center.

Impact of maternal social vulnerability and timing of prenatal care on outcome of prenatally detected congenital heart disease

OBJECTIVES

Early prenatal detection of congenital heart disease (CHD) allows mothers to plan for their pregnancy and delivery; however, the effect of certain sociodemographic and fetal factors on prenatal care has not been investigated thoroughly. This study evaluated the impact of maternal and fetal characteristics on the timing of prenatal diagnosis of CHD and fetal and postnatal outcomes.

METHODS

This retrospective multicenter cohort study included women with a fetal echocardiographic diagnosis of CHD between 2010 and 2019. Women were grouped into quartiles of social vulnerability (quartiles 1-4; low-high) using the 2014 social vulnerability index (SVI) provided by the Centers for Disease Control and Prevention. A fetal disease severity score (range, 1-7) was calculated based on a combination of CHD severity (mild = 1; moderate = 2; severe, two ventricles = 3; severe, single ventricle = 4 points) and prenatally diagnosed genetic abnormality, non-cardiac abnormality and fetal hydrops (1 point each). Late diagnosis was defined as a fetal echocardiographic diagnosis of CHD after 24 weeks' gestation. Univariate and multivariable regression analyses were used to identify factors associated with late diagnosis, termination of pregnancy (TOP), postnatal death, prenatal-postnatal discordance in CHD diagnosis and severity and, for liveborn infants, to identify which prenatal variables were associated with postnatal death or heart transplant.

RESULTS

Among 441 pregnancies included, 94 (21%) had a late diagnosis of CHD. Late diagnosis was more common in the most socially vulnerable quartile, 38% of women in this group having diagnosis > 24 weeks, compared with 14-18% in the other three quartile groups. Late diagnosis was also associated with Catholic or other Christian religion vs non-denominational or other religion and with a lower fetal disease severity score. There were 93 (21%) TOP and 26 (6%) in-utero fetal demises. Factors associated with TOP included early diagnosis and greater fetal disease severity. Compared with the other quartiles, the most socially vulnerable quartile had a higher incidence of in-utero fetal demise and a lower incidence of TOP. Among the 322 liveborn infants, 49 (15%) died or underwent heart transplant during the follow-up period (range, 0-16 months). Factors associated with postnatal death or heart transplant included longer delay between obstetric ultrasound examination at which CHD was first suspected and fetal echocardiogram at which CHD was confirmed and greater fetal disease severity.

CONCLUSIONS

High social vulnerability, Catholic or other Christian religion and low fetal disease severity are associated with late prenatal CHD diagnosis. Delays in CHD diagnosis are associated with fewer TOPs and worse postnatal outcome. Therefore, efforts to expedite fetal echocardiography following abnormal obstetric screening, particularly for at-risk women (e.g. those with high SVI), have the potential to impact pregnancy and postnatal outcome among the prenatally diagnosed CHD population. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal Diagnosis of Dextroposition, Left Pulmonary Artery Sling, Partial Anomalous Left Pulmonary Artery, and Aortic Coarctation

•LPA sling is a rare anomaly definable by fetal echocardiography. •LPA sling is frequently associated with significant respiratory morbidity and mortality. •Fetal diagnosis should prompt planning for postnatal management at a pediatric center. •We present a fetal case of dextroposition, partial LPA sling, and aortic coarctation. •Progressive dextroposition was an indicator for the presence of an LPA sling.

Second trimester fetal thymus size in association to preterm birth

OBJECTIVES

The aim of this study was to compare the second trimester thymus-thorax-ratio (TTR) between fetuses born preterm (study group) and those born after 37 weeks of gestation were completed (control group).

METHODS

This study was conducted as a retrospective evaluation of the ultrasound images of 492 fetuses in the three vessel view. The TTR was defined as the quotient of a.p. thymus diameter and a.p. thoracic diameter.

RESULTS

Fetuses that were preterm showed larger TTR (p<0.001) the second trimester than those born after 37 weeks of gestation were completed. The sensitivity of a binary classifier based on TTR for predicting preterm birth (PTB) was 0.792 and the specificity 0.552.

CONCLUSIONS

In our study, fetuses affected by PTB showed enlarged thymus size. These findings led us to hypothesize, that inflammation and immunomodulatory processes are altered early in pregnancies affected by PTB. However, TTR alone is not able to predict PTB.

Transition in cardiology 2: Maternal and fetal congenital heart disease

The number of women with congenital heart disease (CHD) reaching reproductive age has been increasing. Many women with CHDs are desirous of pregnancy, but they face issues regarding preconception, antepartum, and postpartum management. On the other hand, the fetal diagnosis of CHD has improved with advances in the technique and equipment for fetal echocardiography. Recently, experiences with fetal intervention have been reported in patients with severe CHD, such as critical aortic stenosis. Nevertheless, some types of CHD are challenge to diagnose prenatally, resulting in adverse outcomes. Medical care is part of the transitional care for women and fetuses with CHD during the perinatal period. Pre-conceptional and prenatal counseling play an important role in transitional care. Sex and reproductive education need to be performed as early as possible. We herein review the current status, important issues to be resolved, and the future of maternal and fetal CHD to relevant caregivers.

Prenatal Diagnosis of Double Aortic Arch: Associated Findings and Postnatal Clinical Outcomes

OBJECTIVES

The aim of this study is to share our experience in the prenatal diagnosis and characteristics of double aortic arc and neonatal consequences.

METHODS

We retrospectively analyzed 2153 fetal echocardiography reports between 2014 and 2019 years. Records of 14 fetuses with double aortic arc were examined. Prenatal and postnatal medical records, sonographic images, genetic reports, associated cardiac and extracardiac anomalies, and neonatal clinical results of affected fetuses were reviewed retrospectively.

RESULTS

DAA was isolated in 9 of 14 (64.2%) cases, while the other five cases had cardiac or extracardiac accompanying ultrasound findings. Three of cases (21.4%) were associated with other heart pathologies, including ventricular septal defect, double outlet right ventricle, and persistent left superior vena cava. In 10 cases (71.43%), the right aortic arch diameter was dominant. The left aortic arc was dominant in two cases and both arcs were symmetrical in the remaining two cases. 22q11 microdeletion was the only chromosomal abnormality and was detected in two of nine patients who accepted genetic analysis. Intrauterine fetal death occurred in two of the cases. After birth, in 58.3% (7/12) of the live born cases various degrees of symptoms. Surgical repair was performed with the division of the aorta to all symptomatic cases at different times according to severity of the complaints.

CONCLUSIONS

Since it can cause severe respiratory distress in the postnatal period and may accompany chromosomal anomalies, it is important to provide antenatal diagnosis of double aortic arc and adequate counseling to the family.

Prenatal diagnosis of vascular rings and outcome

Background :

Vascular rings (VRs) present with varied symptoms and may result in significant morbidity before an accurate diagnosis is made. Prenatal diagnosis may be useful to plan surgery after birth.

Objectives :

The purpose of the study was to see the feasibility of accurate diagnosis of VR during antenatal ultrasound examination and describe their outcome.

Methods :

This is a retrospective observational study between January 2014 and December 2019. Vascular rings were diagnosed on the basis of three vessel tracheal view and neck vessels arrangements on fetal echocardiogram. Postnatal evaluation by transthoracic echocardiography and computerized tomography angiogram was performed. Surgical repair was done as per standard indications.

Results :

A total of 35 cases of fetal VRs (median gestational age: 24 weeks [range: 19–35]) were diagnosed during the study period. There were four dichorionic diamniotic twin gestation pregnancies. The right aortic arch (RAA) with anomalous left subclavian artery (ALSA) was suspected in 31 fetuses, double aortic arch (DAA) in 3, and circumflex aorta in 1. Twenty-six (74%) patients had successful deliveries. One patient had a spontaneous miscarriage, 2 underwent termination, and 6 were lost to follow-up. Postnatal assessment showed RAA with ALSA in 18, DAA in 5, circumflex aorta in 2, and no abnormality in 1. Twenty-two (86%) were operated (RAA with ALSA: 17, DAA: 4, and circumflex aorta: 1) and four were waiting for surgery. Two patients died due to prematurity-related complications. All survivors are symptom free during follow-up (median: 2.24; range: 0.2–5.6 years).

Conclusions :

Fetal echocardiography enables prenatal diagnosis and planning of postnatal repair of VRs.

The Differential Diagnosis of Double Aortic Arch and Right Aortic Arch with Mirror-Image Branches in the Fetus: A Potential Novel Method

The objective of this study was to explore a new method for the differential diagnosis between fetal double aortic arch (DAA) and right aortic arch with mirror-image branches (RAA-MB). Clinical data and prenatal echocardiographic features of the DAA (n = 22) and RAA-MB (n = 65) confirmed by postnatal or autopsy findings were analyzed retrospectively. The angles between the two aortic arches in the DAA group and between the right aortic arch and the mirror branch were measured. The differences between the two groups and differential diagnosis value of the angles were compared and analyzed based on the receiver operating characteristic curve. The proportion of left-sided ductal arteriosus (100%) was higher in the DAA group than that (32.3%) in the RAA-MB group, (P < 0.05). The proportion of conotruncal anomalies is higher in the RAA-MB group (64.6%) than in the DAA group (18.2%) (P < 0.05). There was a significant difference in the angles between the groups (DAA: 50.3° ± 8.3° vs. RAA-MB: 82.9° ± 13.8°) (P < 0.01). When the cutoff value was 62.8°, the sensitivity and specificity of the differential diagnosis were 95.5% and 96.9%, respectively. Distinguishing the angle measurement between DAA and RAA-MB is helpful in prenatal prognosis. We recommend a cutoff value of 62.8°.

Ultrasound Patterns in the First Trimester Diagnosis of Congenital Heart Disease

Congenital heart disease (CHD) is the most common birth defect, with a reported prevalence of 5–12 per 1000 live births. Very recently, the American Institute of Ultrasound in Medicine published a guideline recommending the use of the four-chamber and the three-vessel and trachea views to screen for CHD in the first trimester of pregnancy. Our aim is to present abnormal image patterns that are seen in the four-chamber, three-vessel, and trachea views of the fetal heart in the first trimester and to describe their association with specific CHD types. We used a total of 29 cases of CHD from the archives of Filantropia Hospital and the Maternal and Child Health Institute (INSMC) fetal medicine units. We selected cases with a clear and well-documented diagnosis of the CHD type. We identified a series of repeating color doppler flow patterns seen in the four-chamber, three-vessel, and trachea views of the studied cases. Our observations could be developed into a diagnosis algorithm to orientate the examiner to the most likely type of CHD in individual cases.

Diagnostic accuracy of ultrasound screening for fetal structural abnormalities during the first and second trimester of pregnancy in low‐risk and unselected populations

This is a protocol for a Cochrane Review (diagnostic). The objectives are as follows:

The main objectives of this review are to assess the diagnostic accuracy of first‐ and second‐trimester fetal anomaly screening in low‐risk pregnant women, and to compare overall performance of single‐ and two‐stage screening approaches with regards to the number of cases detected before birth, as well as the proportion of false positive diagnoses.

Prenatal diagnosis of aortic arch anomalies: Echocardiography, 3D-ultrasonography, and computed tomography angiogram findings. A case-report

We report the case of a fetus presenting aortic arch anomalies associated with a ventricular septal defect (VSD). This fetus, which was referred at 25 weeks of gestation, was suspected to have coarctation of aorta (CoA) evidenced by enlarged right chambers at the four-chamber view during a routine obstetric ultrasonographic scan. The prenatal diagnosis of CoA remains a challenge. Here, we review the ultrasonographic findings that could contribute to this diagnosis.

Comparison of the 1-year survival rate in infants with congenital heart disease diagnosed by prenatal and postnatal ultrasound: A retrospective study

The impact of prenatal diagnosis on the survival outcome of infants with congenital heart disease (CHD) is still unclear. This study aimed to compare the 1-year survival rate between the prenatally and postnatally diagnosed infants with CHDs.A single-center population-based retrospective cohort study was performed on data from all infants diagnosed with CHD born between January 1998 and December 2017. Among infants with isolated CHDs, the 1-year Kaplan-Meier survival probabilities for prenatal and postnatal diagnosis were estimated. Cox proportional hazard ratios were adjusted for critical CHD (CCHD) status and gestational age.A total of 424 (40 prenatally and 384 postnatally) diagnosed infants with CHDs were analyzed. Compared with non-CCHDs, infants with CCHDs were more likely to be prenatally diagnosed (55.0% vs 18.0%; P < .001). Among the 312 infants with isolated CHDs, the 1-year survival rate for the prenatally diagnosed was significantly lower than postnatally diagnosed (77.1% vs 96.1%; P < .001). For isolated CCHDs, the 1-year survival rate for the prenatally diagnosed was significantly lower than postnatally diagnosed (73.4% vs 90.0%; P < .001). The 1-year survival rate was increased with the increase of age at diagnosis. Among infants with isolated CHDs and CCHDs, the adjusted hazard ratios for 1-year mortality rates for the prenatally versus postnatally diagnosed were 2.554 (95% confidence interval [CI], 1.790, 3.654; P < .001) and 2.538 (95% CI: 1.796, 3.699; P < .001), respectively.Prenatal diagnosis is associated with lower 1-year survival rate for infants with isolated CCHDs. This could probably due to variation in the disease severity among the CCHD subtypes.

Fetal Vascular Rings and Pulmonary Slings: Strategies for Two- and Three-Dimensional Echocardiographic Diagnosis

Fetal aortic arch anomalies and pulmonary slings can be difficult to accurately diagnose but have important clinical implications related to vascular rings, congenital heart disease, and chromosomal anomalies. In this article, the authors briefly review the embryology and development of the fetal arch to facilitate understanding of its diverse variants. Two-dimensional echocardiographic characteristics are summarized for each type of these malformations to propose a strategy for fetal diagnosis. The added benefits of three-dimensional echocardiography with spatiotemporal image correlation are also shown. Finally, the authors propose a strategy for volume acquisition and postanalysis to spur postanalysis clinical use of this technology.

Initial validation of the diagnostic performance of Thymic-Thoracic Ratio as a marker of conotruncal abnormalities and for prediction of surgical prognosis in fetuses without 22q11.2 deletion

AIM

The present study aimed to perform an initial validation of the Thymic-Thoracic Ratio as a sonographic marker of conotruncal defects in non-syndromic fetuses and to assess the possible correlation between the grade of thymic hypoplasia and the severity of conotruncal defects.

METHODS

The study was conducted between January and June 2018 on singleton pregnant women who underwent fetal echocardiography at our institution. Fetuses with a diagnosis of conotruncal defects without 22q11.2 deletion composed the study group, while healthy appropriate for gestational age fetuses composed the control group. The Thymic-Thoracic Ratio was measured in all included fetuses and compared between the study and control group. A ROC curve analysis to evaluate the diagnostic performance of Thymic-Thoracic Ratio toward the diagnosis of conotruncal defects was performed, with determination of sensitivity, specificity, PPV, NPV, positive likelihood ratio, and negative likelihood ratio. The severity of conotruncal defects was defined with the Aristotle score in each newborn who underwent a surgical operation. The correlation between Thymic-Thoracic Ratio and Aristotle score was assessed.

RESULTS

During the study period, 23 fetuses with conotruncal defects without 22q11.2 deletion constituted the study group, and 67 healthy appropriate for gestational age fetuses were included in the control group. The T-T ratio of the study group was significantly lower than the control group (0.32 ± 0.08 vs. 0.41 ± 0.08, p < .001). The ROC curve analysis showed an AUC of 0.80 (95% CI, 0.71-0.89, p < .001) and a T-T ratio cutoff value of 0.35 for the identification of a CTD, with a sensibility of 73.9% (95% CI: 51.6-89.8%), a specificity of 79.1% (95% CI: 67.4-88.1%) a PPV of 54.8% (95% CI: 41.8-67.3%), a NPV of 89.8% (95% CI: 81.5-94.7), a positive likelihood ratio of 3.54 (95% CI 2.09-5.98), and a negative likelihood ratio of 0.33 (95% CI 0.16-0.66). A negative correlation between Aristotle score and T-T ratio was found, with a Kendall-Tau coefficient of -0.41, p = .04.

CONCLUSION

T-T ratio measurement could be useful to identify fetuses at higher risk of conotruncal heart diseases, even without chromosomic deletion, with a cutoff of 0.35. Since a lower T-T ratio seems to be related to a worse surgical neonatal prognosis, it could be possible to provide effective counseling and refer patients to high-specialized centers for fetal echocardiography and cardiac surgery.

Prenatal diagnosis of transposition of the great arteries: an updated review

Simple transposition of the great arteries (TGA) is a cyanotic heart disease that accounts for 5% to 7% of all congenital heart diseases. It is commonly underdiagnosed in utero, with prenatal detection rates of less than 50%. Simple TGA is characterized by ventriculoarterial discordance, atrioventricular concordance, and a parallel relationship of TGA. The prenatal diagnosis of TGA influences postnatal outcomes and therefore requires planned delivery and perinatal management. For these reasons, it is important to identify the key ultrasound markers of TGA to improve the prenatal diagnosis and consequently provide perinatal assistance. The presence of two vessels instead of three in the three-vessel tracheal view, a parallel course of TGA, and identification of the origin of each of TGA are the key markers for diagnosing TGA. In addition to the classical ultrasound signs, other two-dimensional ultrasound markers such as an abnormal right convexity of the aorta, an I-shaped aorta, and the "boomerang sign" may also be used to diagnose TGA in the prenatal period. When accessible, an automatic approach using four-dimensional technologies such as spatio-temporal image correlation and sonographically-based volume computer-aided analysis may improve the prenatal diagnosis of TGA. This study aimed to review the ultrasound markers that can be used in the antenatal diagnosis of TGA, with a focus on the tools used by ultrasonographers, the obstetric and fetal medicine team, and perinatal cardiologists to improve the diagnosis of this condition.

The construction and application of an ultrasound and anatomical cross-sectional database of structural malformations of the fetal heart

OBJECTIVES

Establish a fetal heart anatomical cross-sectional database that correlates with screening transverse ultrasound images suggested by international professional organizations to detect congenital heart defects.

METHODS

Fetuses with suspected congenital heart defects identified using the following cardiac image sequences obtained from transverse slices beginning from the upper abdomen and ending in the upper thorax were the subjects of this study: (1) four-chamber view, (2) left ventricular outflow tract view, (3) three-vessel right ventricular outflow tract view, and (4) the three-vessel tracheal view. A database of digital two-dimensional images of the transverse sweep was created for fetuses with confirmed congenital heart defects. In addition, using four-dimensional ultrasound spatial-temporal image correlation, selected transverse ultrasound images were acquired as part of the database. Ultrasound-detected congenital heart defects were confirmed postnatally from pathological specimens of the heart and lungs using a cross-sectional technique that mirrored the ultrasound images described above. When anatomical specimens were not available, prenatal ultrasound-detected congenital heart defects were confirmed using postnatal echocardiography and/or following surgery.

RESULTS

The four screening views described in the Methods section identified 160 fetuses that comprised the database. Forty-five datasets consisted of both ultrasound and anatomical cross-sectional images. Thirteen percent (6/45) only had abnormalities of the four-chamber view (eg, endocardial cushion defects). Twenty-four percent (11/45) had abnormalities of the four-chamber view as well as right and left outflow tracts (eg, complex malformations). Of these, 10 of 11 had an abnormal tracheal view. Sixteen percent (7/45) had an abnormal four-chamber view and abnormal right outflow tract (eg, pulmonary stenosis). Thirty-three percent (15/45) had a normal four-chamber view but had abnormal right and left outflow tracts as well as an abnormal tracheal view (eg, tetralogy of Fallot, D-transposition of the great arteries).

CONCLUSIONS

Combining both ultrasound and anatomical imaging may be of assistance in training imagers to recognize cardiovascular pathology when performing the screening examination of the fetal heart.

Novel foetal echocardiographic image processing software (5D Heart) improves the display of key diagnostic elements in foetal echocardiography

Background

To evaluate the clinical value of foetal intelligent navigation echocardiography (5D Heart) for the display of key diagnostic elements in basic sections.

Methods

3D volume datasets of 182 normal singleton foetuses were acquired with a four chamber view by using a volume probe. After processing the datasets by using 5D Heart, eight cardiac diagnostic planes were demonstrated, and the image qualities of the key diagnostic elements were graded by 3 doctors with different experiences in performing foetal echocardiography.

Results

A total of 231 volume datasets acquired from the 182 normal foetuses were used for 5D Heart analysis and display. The success rate of 8 standard diagnostic views was 88.2%, and the success rate of each diagnostic view was 55.8–99.2% and 70.7–99.0% for the random four chamber view as the initial section and for the apical four chamber view as the initial section, respectively. The success rate of each diagnostic element in the 8 diagnostic sections obtained by 5D Heart was 58.9%~ 100%. Excellent agreement was found between experienced sonographers and less-experienced sonographers (kappa> 0.769). Inter- and intra-observer agreement were substantial to near-perfect, kappa values ranging from 0.612 to 1.000 (Cohen’s kappa).

Conclusions

5D Heart can significantly improve the image quality of key diagnostic elements in foetal echocardiography with low operator dependency and good reproducibility.

[The left outflow tract: Abnormal features]

The good knowledge of the characteristics of the left outflow tract allows us to detect but also to identify anomalies such as conal VSD and conotruncal anomalies. The analysis of this specific area of the heart must always be performed as part of a global analysis of the outflow tracts, combining the analysis of the right outflow tract with the assessment of the three vessel and trachea view.

The Fetal 3-Vessel Views: An Illustrative Case-Based Tutorial

In 2018, the American Institute of Ultrasound in Medicine revised its obstetric Practice Parameter for the second-trimester fetal anatomic survey. The 2018 Practice Parameter recommends incorporation of the 3-vessel view and 3-vessel and trachea view "if technically feasible." Sonographers and other medical providers may require additional training and education to develop greater proficiency in obtaining and interpreting these views. This pictorial essay, including ultrasound images alongside their respective schematic diagrams, provides an up-to-date, practical, and clinically oriented review of the 3-vessel view and 3-vessel and trachea view and their most common presentations in the context of congenital heart disease.

The gap between the aorta and the superior vena cava: A sonographic sign of persistent left superior vena cava and associated abnormalities

OBJECTIVES

To assess the distance between the right superior vena cava (SVC) and the aorta in fetuses with bilateral superior vena cava as a possible sonographic marker for this.

METHODS

This was a nested case-control study including 20 cases of bilateral SVC and 40 gestational age-matched controls. The distance between the right SVC and the aorta was measured at the level of the three-vessel trachea view in stored images, as well as the diameters of the aorta and the right SVC.

RESULTS

The distance between the aorta and the right SVC was significantly larger in the cases of a left SVC compared with controls, P < .001. A distance of 2.0 mm or more was found in 70% of the cases and 5% of the controls, with a gestational-age adjusted area under the receiver-operating characteristics (ROC) curve for the diagnosis of left SVC of 0.93 (95% CI 0.87-0.99). The aorta and the right SVC were significantly smaller in cases compared with controls, and there was a significant association with other cardiac and extracardiac abnormalities amongst cases of persistent left SVC.

CONCLUSION

An increased distance between the aorta and the right SVC is associated with the diagnosis of bilateral SVC.

Screening performance of congenital heart defects in first trimester using simple cardiac scan, nuchal translucency, abnormal ductus venosus blood flow and tricuspid regurgitation

OBJECTIVE

The objective of this study was to analyze if the addition of simple cardiac scan in cases with increased nuchal translucency (NT) and/or abnormal ductus venosus (DV) blood flow, and/or tricuspid regurgitation (TCR) can improve detection of congenital heart defects (CHD) in chromosomally normal fetuses without non-cardiac defects at 11-13 + 6 gestational weeks in a population of singleton pregnancies.

METHODS

During the 10 years period, all singleton pregnancies at 11-13 + 6 weeks were routinely scanned for NT, DV blood flow and TCR assessment and, if a single of these parameters was abnormal, simple cardiac scan with 2D gray scale and color and/or directional power Doppler in 4-chamber (4-CV) and 3 vessel and trachea views (3VTV) was performed.

RESULTS

The sensitivity and specificity of NT ≥ 95th + DV R/A a-wave + TCR in detecting CHD were 77% and 97%, respectively, and of simple cardiac scan, 67% and 98%, respectively. Area under the curve of receiver operating characteristic curve of NT ≥ 95th + DV R/A a-wave + TCR was 0.838, and of NT ≥ 95th + DV R/A a-wave + TCR + simple cardiac scan was 0.915.

CONCLUSIONS

In chromosomally normal fetuses without non-cardiac anomalies, addition of simple cardiac scan to the combined first trimester screening parameters improves detection of major CHD during first trimester.

[Isolated right aortic arch: prenatal diagnosis characteristics, pregnancy outcomes and systematic review]

OBJECTIVE

To investigate prenatal diagnosis characteristics and pregnancy outcomes associated with isolated right aortic arch (RAA).

METHODS

A retrospective study including fetuses with isolated RAA, managed between January 2010 and February 2018. Cases were identified from the ultrasound databases of the expert pediatric cardiologists, who made the aforementioned diagnosis. All fetuses were examined by a fetal medicine imaging expert to exclude any extracardiac abnormality. A systematic review was performed to assess the prenatal diagnosis and outcomes of fetuses with isolated RAA.

RESULTS

Fifty-six fetuses were diagnosed with an isolated RAA. An isolated double aortic arch (DAA) was diagnosed in one fetus. Mean gestational age at diagnosis was 24 weeks. The sex ratio (boy/girl) was 0.89. No significant abnormality was detected in invasive tests (karyotype and FISH or microarray). Only one fetus was misdiagnosed with isolated RAA. He was the only symptomatic (stridor) newborn baby and was later diagnosed with DAA. Four studies were included in our systematic review representing 115 cases of isolated RAA. One significant chromosomal abnormality was detected: a 22q11 deletion in a newborn baby who had a postnatal finding of a soft palate cleft. There was one major obstetric complication: an intrauterine fetal demise at 41 gestational weeks.

CONCLUSION

Diagnosis of isolated RAA can be challenging. Invasive tests are to be discussed. The diagnosis of isolated RAA should not change obstetric monitoring. Nevertheless, an echocardiography should be performed systematically in these new newborn babies within their first month of life.

[The left outflow tract: Normal features]

Congenital heart disease remains an important cause of perinatal morbidity and mortality. Screening for these is based on a good knowledge of normal fetal heart anatomy and ultrasound views to be performed. After recommending the use of the four chambers and the right outflow tract views in 2005, CNEOF proposes recently adding the left outflow tract assessment. The use of this one should sensitize the operator to the notion of sweeping essential to obtain all these views and make it possible to improve the detection of the conal VSD and conotruncal pathologies.

Detailed Fetal Anatomic Ultrasound Examination: Effect of the 2014 Consensus Report on a Tertiary Referral Center

This study evaluates the impact of extended cardiac views on examination time, repeat imaging, and anomaly detection before and after implementation of 76811 guidelines (American Institute of Ultrasound in Medicine Consensus 2014). It is a retrospective study of singleton pregnancies undergoing detailed ultrasound imaging at 18 weeks' gestation or greater before and after the protocol change in an academic, tertiary care fetal center. Views required prior to 2014: 4-chamber, left outflow tract, right outflow tract. Additional views required after 2014: bicaval, aortic arch, 3-vessel, and 3-vessel trachea. Fetuses with known anomalies were excluded. Rates of detection of congenital heart disease (CHD), examination completion, repeat examination recommendation, fetal echocardiogram recommendation, completion by body mass index, and cardiac examination time were determined. Six hundred twenty-four subjects were included, 217 before and 407 after protocol change. Views obtained were as stated in the American Institute of Ultrasound in Medicine/Society for Maternal-Fetal Medicine consensus. Detection of CHD was not improved. Examination times increased by 20% (6.4 vs 7.7 minutes, P < 0.05). Number of incomplete studies increased by 130% (11% to 26%, P < 0.05). Twice as many patients were referred for repeat examination (6% vs 13%, P < 0.05). Completion rates were negatively correlated with body mass index. Recommendations for fetal echocardiogram were unchanged (5% vs 6%, P = 0.6). Additional imaging did not increase detection rate of CHD (3% vs 2%, P = 0.3). Extended cardiac views resulted in increased examination time, more incomplete examinations, and more repeat examinations without changing detection rates of CHD.

Prenatal echocardiographic assessment of right aortic arch

OBJECTIVES

To report our experience with fetal diagnosis of right aortic arch (RAA) variants based on the ductus arteriosus (DA) anatomy and brachiocephalic vessel branching pattern in relation to the trachea, and to establish whether the echocardiographic 'V-shaped' or 'U-shaped' appearance of the junction between the DA and aortic arch (AA) in the fetal upper mediastinal view is sufficiently accurate for assessment of fetal AA anatomy.

METHODS

This was a retrospective study of pregnancies with a prenatal diagnosis of fetal RAA that had postnatal confirmation of AA anatomy, referred to our tertiary center during 2011-2017. Prenatal and postnatal medical records, including echocardiographic and computed tomography (CT)/magnetic resonance imaging (MRI) scan reports, were reviewed, and cardiac and extracardiac abnormalities and the results of genetic testing were recorded.

RESULTS

Of 55 consecutive pregnancies with a prenatal diagnosis of fetal RAA, six were lost to follow-up, one was terminated and three were excluded due to lack of postnatal confirmation of AA anatomy. Of the remaining 45 pregnancies, AA anatomy was assessed postnatally by CT in 39, by MRI in one and by direct examination at cardiac surgery in five. A U-shaped appearance was found in 37/45 (82.2%) patients, all of which had a complete vascular ring (CVR). Of these 37 patients, on postnatal confirmation, 21 (56.8%) had RAA with Kommerell's diverticulum, left posterior ductus arteriosus (LPDA) and aberrant left subclavian artery (ALSA) (RAA/LPDA/ALSA), 11 (29.7%) had a double AA (DAA), four (10.8%) had RAA with Kommerell's diverticulum, LPDA and mirror-image (MI) branching (RAA/LPDA/MI), and one (2.7%) had RAA with Kommerell's diverticulum, LPDA and aberrant left innominate artery (ALIA) (RAA/LPDA/ALIA). A V-shaped appearance was found in 3/45 (6.7%) patients, all of which had RAA with right DA not forming a CVR and MI branching. In the 5/45 (11.1%) fetuses with neither U- nor V-shaped appearance, RAA with left anterior DA arising from the left innominate artery and MI branching, not forming a CVR, was found. Twelve (26.7%) fetuses had a congenital heart defect (CHD). RAA forming a CVR (U-shaped appearance) was associated with a septal defect in 6/37 (16.2%) fetuses, while RAA not forming a CVR (V-shaped appearance or no U- or V-shaped appearance) was associated with major CHD in 6/8 (75.0%) fetuses.

CONCLUSIONS

In fetuses with RAA, V-shaped appearance of the junction between the DA and AA indicates only that the transverse AA and DA run together on the same side of the thorax (trachea) while a U-shaped appearance is always a sign of a CVR. Among fetuses with a CVR, RAA/LPDA/MI is more frequent than described previously. Finally, RAA forming a CVR is not usually associated with complex CHD, as opposed to RAA not forming a CVR. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Ductus arteriosus and fetal echocardiography: Implications for practice

The ductus arteriosus (DA) is a crucial part of the fetal circulation, both in the normal fetus and in critical congenital heart disease (CHD). It allows shunting between the pulmonary and systemic circulations. In physiological prenatal conditions, the DA lets the majority of right ventricular output bypass the fluid-filled, high-resistance lungs. The DA can cause hemodynamic compromise in the fetus and neonate when constricted or absent (in isolation or in patients with CHD) and may lead to pre- or postnatal sequelae within other systems when forming part of a vascular ring. In CHD, the DA can be interrogated by fetal echocardiography to infer information regarding severity of pulmonary outflow tract obstruction, adequacy of the sub-pulmonary ventricle to supply pulmonary blood flow, and to predict the likelihood of atrial septum restriction in transposition of the great arteries. A good understanding of the DA is crucial for fetal cardiologists.

"Y Sign" at the Level of the 3-Vessel and Trachea View: An Effective Fetal Marker of Aortic Dextroposition Anomalies in the First Trimester

OBJECTIVES

The "Y sign" at the level of the 3-vessel and trachea view corresponds to thinning of main pulmonary artery and arterial duct and a dilated transverse aortic arch. The purpose of this study was to evaluate the Y sign for the diagnosis of aortic dextroposition anomalies at the time of the first-trimester scan and to assess the screening performance of only the Y sign, only abnormal left axis deviation (axis sign), and their combination for the diagnosis of aortic dextroposition anomalies.

METHODS

A prospective evaluation of 6025 pregnant women undergoing first-trimester ultrasonography was conducted. The cardiac axis was measured in all examined patients and considered abnormal (positive axis sign) at greater than 57 °. The frequency of the Y sign and the axis sign was assessed for this population, and their screening performance for the diagnosis of aortic dextroposition anomalies was calculated.

RESULTS

A total of 5775 patients fulfilled the inclusion criteria. Aortic dextroposition anomalies were diagnosed in 17 cases (tetralogy of Fallot in 8 and Fallot-like double-outlet right ventricle in 9). The Y sign was found in 18 of 5775 (0.3%) fetuses examined, of which 7 of 18 were confirmed with tetralogy of Fallot, 9 of 18 with a Fallot-like double-outlet right ventricle, and 2 of 18 with pulmonary stenosis. A positive axis sign of greater than 57 ° was found in 20 fetuses, including 4 with normal heart anatomy. The sensitivity values of the Y sign, the axis sign, and their combination were 94%, 76%, and 94%, respectively.

CONCLUSIONS

Visualization of the Y sign should increase the suspicion of aortic dextroposition anomalies in the late first trimester. The screening performance of the Y sign alone and in combination with an abnormal cardiac axis was high and may aid in the early diagnosis of aortic dextroposition anomalies in the fetus.

Right aortic arch with bilateral arterial duct and nonconfluent pulmonary arteries without associated cardiac defects: Prenatal diagnosis and successful postnatal treatment

We describe a rare case of right aortic arch with bilateral arterial duct and disconnected left pulmonary artery. Prenatal diagnosis allowed to plan delivery at the referral center and to maintain perfusion of the disconnected pulmonary artery through prostaglandin E₁ infusion until surgical reconnection was performed. Early postnatal treatment avoided functional loss of the left lung that would have happened if malformation had not been identified before birth.

Great Vessels Anomalies – Prenatal Echocardiography and Neonatal Angio-CT – A Pictorial Essay

Introduction: Fetal echocardiography is a method of choice for diagnosing cardiovascular anomalies prenatally. However, in the majority of cases, the complexity of a defect creates a diagnostic challenge. Moreover, postnatal validation of sonographic findings rarely can be obtained. Nevertheless, the feedback is vital for improving diagnostic capabilities. Thus, the aim of this research was to compare results of prenatal echocardiography with postnatal angio-CT in patients with anomalies of great vessels. Material and methods: We retrospectively compared results of prenatal echocardiography and postnatal angio-CT in 10 patients with selected anomalies of the aortic arch. This was a qualitative analysis, thus discrepancies in recognized anomalies were compared between these two modalities. Results: In 8/10 patient diagnoses were fully consistent. Nevertheless, the tiny caliber of vessels created a diagnostic challenge (e.x. to differentiate the hypoplastic aortic arch from the aortic arch interruption). In the remaining case, the discrepancy was due to a problem with complete visualization of all branches of the aortic arch in prenatal ultrasound. Conclusions: Fetal echocardiography in tertiary center was a reliable method for assessment of great vessels anomalies. However, critically narrow vessels remain a diagnostic challenge and neonatal angio-CT seems to be the method of choice in cases of diagnostic doubts.

Prenatal diagnosis of congenital heart disease: A review of current knowledge

This article reviews important features to improve the diagnosis of congenital heart disease (CHD) by applying ultrasound in prenatal cardiac screening. As low and high-risk pregnancies for CHD are subject to routine obstetric ultrasound, the diagnosis of structural heart defects represents a challenge that involves a team of specialists and subspecialists on fetal ultrasonography. In this review, the images highlight normal anatomy of the heart as well as pathologic cases consistent with cardiac malposition and isomerism, septal defects, pulmonary stenosis/atresia, aortic malformations, hypoplastic left ventricle, conotruncal anomalies, tricuspid dysplasia, and Ebstein’s anomaly, and univentricular heart, among other congenital cardiovascular defects. Anatomical details of most CHD in fetuses were provided by two-dimensional (2D) ultrasound with higher quality imaging, enhancing diagnostic accuracy in a variety of CHD. Moreover, the accuracy of the cardiac defects in obstetrics ultrasound improves the outcome of most CHD, providing planned delivery, aided genetic counseling, and perinatal management.

Main pulmonary artery cross-section ratio is low in fetuses with tetralogy of Fallot and ductus arteriosus-dependent pulmonary circulation

OBJECTIVES

This study aimed to determine fetal echocardiographic features of tetralogy of Fallot in association with postnatal outcomes.

METHODS

The Z-scores of the main and bilateral pulmonary arteries and the aorta were measured, and the following variables were calculated in 13 fetuses with tetralogy of Fallot: pulmonary artery-to-aorta ratio and main pulmonary artery cross-section ratio - the main pulmonary artery diameter squared divided by the sum of the diameter squared of the left and right pulmonary arteries. Fetuses were classified as having ductus arteriosus-dependent or ductus arteriosus-independent pulmonary circulation.

RESULTS

We included two infants with pulmonary atresia and six infants with ductus-dependent pulmonary circulation, who underwent systemic-to-pulmonary shunt surgeries at ⩽1 month of age. The Z-scores of the main pulmonary artery and the pulmonary artery-to-aorta ratio in fetuses with ductus-dependent pulmonary circulation were lesser than those in fetuses with ductus independence, but not significantly. The main pulmonary artery cross-section ratio in fetuses with ductus dependence was significantly lesser (0.65±0.44 versus 1.56±0.48, p<0.005). Besides, the flow of the ductus arteriosus was directed from the aorta to the pulmonary artery in the ductus arteriosus-dependent group during the fetal period.

CONCLUSIONS

The main pulmonary artery cross-section ratio was the most significant variable for predicting postnatal outcomes in fetuses with tetralogy of Fallot.