Comparison of echocardiographic findings in fetuses at less than 15 weeks' gestation with later cardiac evaluation

Machine Learning to Predict Outcomes of Fetal Cardiac Disease: A Pilot Study

Prediction of outcomes following a prenatal diagnosis of congenital heart disease (CHD) is challenging. Machine learning (ML) algorithms may be used to reduce clinical uncertainty and improve prognostic accuracy. We performed a pilot study to train ML algorithms to predict postnatal outcomes based on clinical data. Specific objectives were to predict (1) in utero or neonatal death, (2) high-acuity neonatal care and (3) favorable outcomes. We included all fetuses with cardiac disease at Sunnybrook Health Sciences Centre, Toronto, Canada, from 2012 to 2021. Prediction models were created using the XgBoost algorithm (tree-based) with fivefold cross-validation. Among 211 cases of fetal cardiac disease, 61 were excluded (39 terminations, 21 lost to follow-up, 1 isolated arrhythmia), leaving a cohort of 150 fetuses. Fifteen (10%) demised (10 neonates) and 65 (48%) of live births required high acuity neonatal care. Of those with clinical follow-up, 60/87 (69%) had a favorable outcome. Prediction models for fetal or neonatal death, high acuity neonatal care and favorable outcome had AUCs of 0.76, 0.84 and 0.73, respectively. The most important predictors for death were the presence of non-cardiac abnormalities combined with more severe CHD. High acuity of postnatal care was predicted by anti Ro antibody and more severe CHD. Favorable outcome was most predicted by no right heart disease combined with genetic abnormalities, and maternal medications. Prediction models using ML provide good discrimination of key prenatal and postnatal outcomes among fetuses with congenital heart disease.

Factors affecting the accuracy of fetal cardiac ultrasound screening in the first trimester of pregnancy

PURPOSE

Most studies on the performance of first-trimester cardiac screening have concentrated on comparing the detection rate between different protocols and not on the actual reason for false-negative results. Herein, we report the performance of first-trimester congenital heart disease (CHD) screening and factors that may affect the detection rate of CHDs.

METHODS

This retrospective observational study included patients who underwent first-trimester screening and subsequently gave birth at our facility. We analyzed the performance of first-trimester screening for CHD and major CHD (CHD requiring cardiac surgery or interventional catheterization within 12 months of birth).

RESULTS

Of the 6614 fetuses included, 53 had CHD and 35 had major CHD. For the prenatal diagnosis of CHD, the detection rate, specificity, positive predictive value, negative predictive value, and first-trimester detection rate for CHD were 64.1%, 99.9%, 94.4%, 99.7%, and 82.9%, respectively; the respective values for major CHD were 85.7%, 99.96%, 93.75%, 99.92%, and 85.7%. The detection rate was not significantly different when classified by crown-rump length or number of fetuses. A weak correlation was observed between low detection rate of major CHD and lower maternal body mass index (BMI) (correlation ratio: 0.17). The detection rate was significantly higher when the fetus was scanned with its spine at the 5-7 o'clock position (posterior spine) than at other positions (odds ratio: 3.82, 95% confidence interval: 1.16-12.5, p = 0.02).

CONCLUSION

Posterior spine contributes to an improved diagnostic rate in first-trimester CHD screening. In addition, sonographers must recognize that low maternal BMI is a risk factor of false-negative results.

False-Positive Diagnosis of Congenital Heart Defects at First-Trimester Ultrasound: An Italian Multicentric Study

Objective. Our objective was to assess the proportion of false-positive CHD cases at the first-trimester evaluation of the fetal heart, performed by experienced operators. Methods. This multicenter retrospective study included of pregnant women with suspicion of CHDs during first-trimester screening for aneuploidies. In all cases, the fetal heart assessments were performed by obstetricians with extensive experience in first-trimester scanning, following an extended protocol proposed by SIEOG national guidelines, which included an axial view of the fetal abdomen and chest to assess visceral situs and evaluation of the four-chamber view (4CV) and three-vessel trachea view (3VTV) with color Doppler. In all suspected cases, fetal echocardiography was offered within 16 and/or at 19-22 weeks' gestation. Results. From a population of 4300 fetuses, 46 CHDs were suspected. Twenty-four cases were excluded from this analysis because the parents opted for early termination of the pregnancies due to associated structural and/or genetic anomalies. For the remaining 22, echocardiography was performed by 16 weeks in 14 cases (64%) and after 16 weeks in 8 cases. In 19 cases (86.4%), a fetal cardiologist confirmed the presence of a CHD. In three cases (13%), the cardiac anatomy was found to be normal at the fetal echocardiography and postnatally. Conclusions. This study shows that the proportion of false-positive cases at the first-trimester ultrasound examination of the fetal heart, performed by experienced operators, may carry a higher risk of false-positive diagnosis than expected. Therefore, this issue must be discussed in instances where a CHD is suspected at the first-trimester screening.

Structural and functional fetal cardiac imaging using low field (0.55 T) MRI

Purpose

This study aims to investigate the feasibility of using a commercially available clinical 0.55 T MRI scanner for comprehensive structural and functional fetal cardiac imaging.

Methods

Balanced steady-state free precession (bSSFP) and phase contrast (PC) sequences were optimized by in utero studies consisting of 14 subjects for bSSFP optimization and 9 subjects for PC optimization. The signal-to-noise ratio (SNR) of the optimized sequences were investigated. Flow measurements were performed in three vessels, umbilical vein (UV), descending aorta (DAo), and superior vena cava (SVC) using the PC sequences and retrospective gating. The optimized bSSFP, PC and half-Fourier single shot turbo spin-echo (HASTE) sequences were acquired in a cohort of 21 late gestation-age fetuses (>36 weeks) to demonstrate the feasibility of a fetal cardiac exam at 0.55 T. The HASTE stacks were reconstructed to create an isotropic reconstruction of the fetal thorax, followed by automatic great vessel segmentations. The intra-abdominal UV blood flow measurements acquired with MRI were compared to ultrasound UV free-loop flow measurements.

Results

Using the parameters from 1.5 T as a starting point, the bSSFP sequences were optimized at 0.55 T, resulting in a 1.6-fold SNR increase and improved image contrast compared to starting parameters, as well as good visibility of most cardiac structures as rated by two experienced fetal cardiologists. The PC sequence resulted in increased SNR and reduced scan time, subsequent retrospective gating enabled successful blood flow measurements. The reconstructions and automatic great vessel segmentations showed good quality, with 18/21 segmentations requiring no or minor refinements. Blood flow measurements were within the expected range. A comparison of the UV measurements performed with ultrasound and MRI showed agreement between the two sets of measurements, with better correlation observed at lower flows.

Conclusion

We demonstrated the feasibility of low-field (0.55 T) MRI for fetal cardiac imaging. The reduced SNR at low field strength can be effectively compensated for by strategically optimizing sequence parameters. Major fetal cardiac structures and vessels were consistently visualized, and flow measurements were successfully obtained. The late gestation study demonstrated the robustness and reproducibility at low field strength. MRI performed at 0.55 T is a viable option for fetal cardiac examination.

Cardiac Axis in Early Gestation and Congenital Heart Disease

Congenital heart defects represent the most common structural anomalies observed in the fetal population, and they are often associated with significant morbidity and mortality. The fetal cardiac axis, which indicates the orientation of the heart in relation to the chest wall, is formed by the angle between the anteroposterior axis of the chest and the interventricular septum of the heart. Studies conducted during the first trimester have demonstrated promising outcomes with respect to the applicability of cardiac axis measurement in fetuses with congenital heart defects as well as fetuses with extracardiac and chromosomal anomalies, which may result in improved health outcomes and reduced healthcare costs. The main aim of this review article was to highlight the cardiac axis as a reliable and powerful marker for the detection of congenital heart defects during early gestation, including defects that would otherwise remain undetectable through the conventional four-chamber view.

Risk factors for delayed termination of pregnancy following increased nuchal translucency

OBJECTIVES

Termination of pregnancy after increased nuchal translucency (NT) is a common occurrence. This study aimed to identify characteristics of a cohort with a NT ≥3.0 mm who underwent a pregnancy termination ≥15 weeks compared with those who terminated <15 weeks.

METHODS

All NT ≥3.0 mm identified within our department over an 11-year period (2010-2021) (n = 689) were retrospectively examined and characteristics of the cohort of increased NTs ending in termination were further categorized.

RESULTS

There were 221 (32.1%) individuals with an increased NT (≥3 mm) who underwent a termination of pregnancy within our study period (2010-2021). Pregnancy termination occurred at a gestational age <15 weeks in 162 (73.3%) and ≥15 weeks in 59 individuals. Pregnant individuals without positive NIPT for aneuploidy were at a higher risk for a ≥15-week termination (p = 0.004). In 29% (17/59) of late terminations, there were additional imaging findings after the NT scan (ultrasound, echocardiogram, magnetic resonance imaging) that ultimately triggered the decision to pursue termination.

CONCLUSIONS

As the options for workup of an increased NT expand, potential delays in decision-making surrounding termination increase. This study identifies multiple reasons for delayed termination and proposes several approaches to care aimed at maximizing diagnostic information by imaging and diagnostic testing in an expedited manner.

Pregnancy Termination and Postnatal Major Congenital Heart Defect Prevalence After Introduction of Prenatal Cardiac Screening

Importance

Prenatal cardiac screening of the first and second trimesters has had a major impact on postnatal prevalence of congenital heart defects (CHDs), rates of termination of pregnancy (TOP), and outcomes among children born alive with CHDs.

Objective

To examine the prenatal and postnatal incidence of major CHDs (ie, necessitating intervention within the first year of life), detection rate trends, rates of TOP, and the association of cardiac screening with postnatal outcomes.

Design, Settings, and Participants

In this cross-sectional study, 3827 fetuses with antenatally diagnosed major CHDs in the Czech Republic (population 10.7 million) between 1991 and 2021 were prospectively evaluated with known outcomes and associated comorbidities. Prenatal and postnatal prevalence of CHD in an unselected population was assessed by comparison with a retrospective analysis of all children born alive with major CHDs in the same period (5454 children), using national data registry. Data analysis was conducted from January 1991 to December 2021.

Main Outcomes and Measures

Prenatal detection and postnatal prevalence of major CHDs and rate of TOPs in a setting with a centralized health care system over 31 years.

Results

A total of 3 300 068 children were born alive during the study period. Major CHD was diagnosed in 3827 fetuses, of whom 1646 (43.0%) were born, 2069 (54.1%) resulted in TOP, and 112 (2.9%) died prenatally. The prenatal detection rate increased from 6.2% in 1991 to 82.8% in 2021 (P < .001). Termination of pregnancy decreased from 70% in 1991 to 43% (P < .001) in 2021. Of 627 fetuses diagnosed in the first trimester (introduced in 2007), 460 were terminated (73.3%). Since 2007, of 2066 fetuses diagnosed in the second trimester, 880 (42.6%) were terminated, resulting in an odds ratio of 3.6 (95% CI, 2.8-4.6; P < .001) for TOP in the first trimester compared with the second trimester. Postnatal prevalence of major CHDs declined from 0.21% to 0.14% (P < .001). The total incidence (combining prenatal detection of terminated fetuses with postnatal prevalence) of major CHD remained at 0.23% during the study period.

Conclusions and Relevance

In this cross-sectional study, the total incidence of major CHD did not change significantly during the 31-year study period. The prenatal detection of major CHD approached 83% in the current era. Postnatal prevalence of major CHD decreased significantly due to early TOPs and intrauterine deaths. The introduction of first trimester screening resulted in a higher termination rate in the first trimester but did not revert the overall decreasing trend of termination for CHDs in general.

Prenatal detection of congenital heart disease at 12-13 gestational weeks: detailed analysis of false-negative cases

OBJECTIVES

To report on the early detection of congenital heart disease (CHD) in low- and high-risk populations managed at our hospital; and perform a detailed analysis of false-negative diagnoses, in order to derive possible recommendations on how to reduce their incidence.

METHODS

This was a retrospective observational study analyzing cases which underwent an ultrasound examination at the end of the first trimester at the Fetal Medicine and Surgery Unit of Gaslini Children's Hospital, Genoa, Italy, in the period January 2015 to December 2021. The study population included both low-risk pregnancies that underwent standard first-trimester combined screening and high-risk ones referred to our unit because of a positive combined test or suspicion of fetal anomalies raised in a regional community hospital. For each case, the following variables were retrieved and analyzed: number of fetuses, maternal body mass index, gestational age at first-trimester screening, whether the pregnancy was low or high risk, nuchal translucency thickness (normal or > 99th  centile), type of CHD, associated extracardiac anomalies, karyotype and pregnancy outcome. For low-risk pregnancies, suspicion of CHD was also recorded. In low-risk cases, sonographic cardiac screening comprised evaluation of the four-chamber view (grayscale and color/power Doppler) and three-vessel-and-trachea view (color/power Doppler). High-risk cases underwent early fetal echocardiography. False-negative cases were categorized according to likely cause of the missed diagnosis, as follows: human factor; technical factor; acoustic-window factor.

RESULTS

Gestational age at ultrasound ranged from 12 + 0 to 13 + 6 weeks (crown-rump length (CRL), 50.1-84.0 mm) in the low-risk group and from 11 + 5 to 13 + 6 weeks (CRL, 45.1-84.0 mm) in the high-risk group. Over the 7-year study period, 7080 pregnancies were evaluated in the first trimester. Of these, 6879 (7167 fetuses) were low-risk and 201 were high-risk cases. In the low-risk group, there were 30 fetuses with CHD (including 15 major and 15 minor CHD), yielding a prevalence of 4.2/1000 (2.1/1000 for major CHD). Nine of the 30 CHD cases were suspected at screening ultrasound (7/15 major CHD). Excluding cases in which the CHD would not be expected to be associated with a modification of the screening views and would therefore not be detectable on screening ultrasound, 7/12 cases of major CHD were detected, corresponding to a sensitivity of 58.3%. Among the 201 high-risk cases, there were 46 fetuses with CHD (including 44 major and two minor CHD), of which 43 were detected, corresponding to a sensitivity for early fetal echocardiography of 93.5%, or 97.7% if the two cases that were unlikely to be detectable on first-trimester screening were excluded. Analysis of the 11 (of 24) false-negative cases that would be expected to be picked up on screening views revealed that human error (image interpretation and/or scanning approach) was involved in all 11 cases and technical factors (excessive color priority (color-balance function) and/or incorrect plane alignment) were present in two. There was impairment of the acoustic window (associated with maternal obesity and/or twin gestation) as a cofactor in five of the 11 cases.

CONCLUSIONS

The sensitivity for detection of major CHD of early cardiac screening in low-risk pregnancy is under 60%, partly due to the natural history of CHD and, it seems, partly relating to human error and technical issues with image quality. Factors associated with false-negative diagnoses may be categorized into three types: human error, technical factors and acoustic-window impairment. We recommend: appropriate assessment with fetal posterior spine; that sufficient time is spent on assessment of the fetal situs; and that color/power Doppler settings are adapted to the individual case. A lower threshold for referring doubtful cases for early fetal echocardiography should be adopted in cases of maternal obesity and in twin gestation. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal diagnosis of recurrent hypoplastic left heart syndrome associated with MYH6 variants: a case report

BACKGROUND

Hypoplastic left heart syndrome (HLHS) is a rare but genetically complex and clinically and anatomically severe form of congenital heart disease (CHD).

CASE PRESENTATION

Here, we report on the use of rapid prenatal whole-exome sequencing for the prenatal diagnosis of a severe case of neonatal recurrent HLHS caused by heterozygous compound variants in the MYH6 gene inherited from the (healthy) parents. MYH6 is known to be highly polymorphic; a large number of rare and common variants have variable effects on protein levels. We postulated that two hypomorphic variants led to severe CHD when associated in trans; this was consistent with the autosomal recessive pattern of inheritance. In the literature, dominant transmission of MYH6-related CHD is more frequent and is probably linked to synergistic heterozygosity or the specific combination of a single, pathogenic variant with common MYH6 variants.

CONCLUSIONS

The present report illustrates the major contribution of whole-exome sequencing (WES) in the characterization of an unusually recurrent fetal disorder and considered the role of WES in the prenatal diagnosis of disorders that do not usually have a genetic etiology.

Fetal MRI of the heart and brain in congenital heart disease

Antenatal assessment of congenital heart disease and associated anomalies by ultrasound has improved perinatal care. Fetal cardiovascular MRI and fetal brain MRI are rapidly evolving for fetal diagnostic testing of congenital heart disease. We give an overview on the use of fetal cardiovascular MRI and fetal brain MRI in congenital heart disease, focusing on the current applications and diagnostic yield of structural and functional imaging during pregnancy. Fetal cardiovascular MRI in congenital heart disease is a promising supplementary imaging method to echocardiography for the diagnosis of antenatal congenital heart disease in weeks 30-40 of pregnancy. Concomitant fetal brain MRI is superior to brain ultrasound to show the complex relationship between fetal haemodynamics in congenital heart disease and brain development.

First Trimester Tricuspid Regurgitation: Clinical Significance

Tricuspid regurgitation is a cardiac valvular anomaly that consists of the return of blood to the right atrium during systole due to incomplete valve closure. This structure can be visualized on ultrasound between 11 and 14 weeks of gestation in most cases. Despite being a common finding, even in healthy fetuses, the presence of tricuspid regurgitation may be associated with chromosomal and structural abnormalities. The evaluation of tricuspid flow and the presence of regurgitation on first-trimester ultrasound has shown promising results regarding its role in the early detection of aneuploidies, congenital heart defects, and other adverse perinatal outcomes. This review article aims to demonstrate the importance of tricuspid regurgitation as a secondary marker, and consequently, significant benefits of its early detection when added to the combined first-trimester screening. Its value will be discussed, namely its sensitivity and specificity, alone and together with other current markers in the fetal assessment performed in the first-trimester ultrasound.

Accuracy of the Standardized Early Fetal Heart Assessment in Excluding Major Congenital Heart Defects in High-Risk Population: A Single-Center Experience

OBJECTIVE

To evaluate the ability of standardized early fetal heart assessment (EFHA) that includes the 4-chamber view, outflow tract relationship (OTR), and transverse arches views (TAV) of the great arteries in excluding major congenital heart defects (CHDs) in high-risk populations.

METHODS

This retrospective study included high-risk pregnancies for CHDs undergoing EFHA at 11-14 weeks of gestation. Risk factors for CHDs were diabetes mellitus, a family history of CHDs, a history of a CHD use of teratogenic medications, seizure disorder, assisted reproductive treatment-conceived pregnancy, presence of at least one of the ultrasound markers: enlarged nuchal translucency (>95th percentile), tricuspid regurgitation, and reversed a-wave in the ductus venosus, presence of an extracardiac or a suspected cardiac anomaly, a high-risk first trimester combined screen result, and multiple pregnancies. EFHA consisted of visualization of 4ChV, OTR, and TAV, with and without power Doppler ultrasound. The primary outcome was the negative predictive value of EFHA in excluding major CHDs.

RESULTS

EFHA was performed on 1055 fetuses. Of these, 1024 were used for the final analysis. Of these, 94.9% (n = 923) were singleton. The most common indication for EFHA was maternal DM (n = 231, 22.6%). The sensitivity, specificity, false positive, false negative, and accuracy of EFHA were 93.2%, 99.9%, 1.4%, 0.4%, and 99.5% (P < .0001), respectively, in entire included cases. The performance of EFHA was 88%, 99.9%, 1.4%, 0.4%, and 99.5% (P < .0001) respectively when the terminated cases were excluded.

CONCLUSION

Early fetal heart assessment is feasible for screening for major CHDs in high-risk populations. This approach may be expanded to the general obstetric population.

Postmortem 9.4-T MRI for Fetuses With Congenital Heart Defects Diagnosed in the First Trimester

Objective

To evaluate the feasibility of 9. 4-T postmortem MRI (pm-MRI) for assessment of major congenital heart defects (CHD) cases terminated in the early stage of gestation.

Methods

Fetuses with CHD detected by the detailed first-trimester ultrasound scan and terminated before 18 gestational weeks were recruited between January 2018 and June 2020. All fetuses were offered 9.4-T pm-MRI examinations and those terminated over 13+6 weeks were offered conventional autopsies simultaneously. Findings of pm-MRI were compared with those of conventional autopsy and prenatal ultrasound.

Results

A total of 19 fetuses with major CHD were analyzed, including 6 cases of the atrioventricular septal defect, 5 cases of Tetralogy of Fallot, 3 cases of hypoplastic left heart syndrome, 1 case of tricuspid atresia, 1 case of transposition of the great arteries, 1 case of severe tricuspid regurgitation, and 2 cases of complex CHD. Pm-MRI had concordant findings in 73.7% (14/19) cases, discordant findings in 15.8% (3/19) cases, and additional findings in 10.5% (2/19) cases when compared with prenatal ultrasound. Pm-MRI findings were concordant with autopsy in all 8 CHD cases terminated over 13+6 weeks.

Conclusion

It is feasible to exhibit the structure of fetal heart terminated in the first trimester clearly on 9.4-T pm-MRI with an optimized scanning protocol. High-field pm-MRI could provide medical imaging information of CHD for those terminated in the early stage of gestation, especially for those limited by conventional autopsy.

First-trimester ultrasound detection of fetal heart anomalies: systematic review and meta-analysis

OBJECTIVES

To determine the diagnostic accuracy of ultrasound at 11-14 weeks' gestation in the detection of fetal cardiac abnormalities and to evaluate factors that impact the detection rate.

METHODS

This was a systematic review of studies evaluating the diagnostic accuracy of ultrasound in the detection of fetal cardiac anomalies at 11-14 weeks' gestation, performed by two independent reviewers. An electronic search of four databases (MEDLINE, EMBASE, Web of Science Core Collection and The Cochrane Library) was conducted for studies published between January 1998 and July 2020. Prospective and retrospective studies evaluating pregnancies at any prior level of risk and in any healthcare setting were eligible for inclusion. The reference standard used was the detection of a cardiac abnormality on postnatal or postmortem examination. Data were extracted from the included studies to populate 2 × 2 tables. Meta-analysis was performed using a random-effects model in order to determine the performance of first-trimester ultrasound in the detection of major cardiac abnormalities overall and of individual types of cardiac abnormality. Data were analyzed separately for high-risk and non-high-risk populations. Preplanned secondary analyses were conducted in order to assess factors that may impact screening performance, including the imaging protocol used for cardiac assessment (including the use of color-flow Doppler), ultrasound modality, year of publication and the index of sonographer suspicion at the time of the scan. Risk of bias and quality assessment were undertaken for all included studies using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool.

RESULTS

The electronic search yielded 4108 citations. Following review of titles and abstracts, 223 publications underwent full-text review, of which 63 studies, reporting on 328 262 fetuses, were selected for inclusion in the meta-analysis. In the non-high-risk population (45 studies, 306 872 fetuses), 1445 major cardiac anomalies were identified (prevalence, 0.41% (95% CI, 0.39-0.43%)). Of these, 767 were detected on first-trimester ultrasound examination of the heart and 678 were not detected. First-trimester ultrasound had a pooled sensitivity of 55.80% (95% CI, 45.87-65.50%), specificity of 99.98% (95% CI, 99.97-99.99%) and positive predictive value of 94.85% (95% CI, 91.63-97.32%) in the non-high-risk population. The cases diagnosed in the first trimester represented 63.67% (95% CI, 54.35-72.49%) of all antenatally diagnosed major cardiac abnormalities in the non-high-risk population. In the high-risk population (18 studies, 21 390 fetuses), 480 major cardiac anomalies were identified (prevalence, 1.36% (95% CI, 1.20-1.52%)). Of these, 338 were detected on first-trimester ultrasound examination and 142 were not detected. First-trimester ultrasound had a pooled sensitivity of 67.74% (95% CI, 55.25-79.06%), specificity of 99.75% (95% CI, 99.47-99.92%) and positive predictive value of 94.22% (95% CI, 90.22-97.22%) in the high-risk population. The cases diagnosed in the first trimester represented 79.86% (95% CI, 69.89-88.25%) of all antenatally diagnosed major cardiac abnormalities in the high-risk population. The imaging protocol used for examination was found to have an important impact on screening performance in both populations (P < 0.0001), with a significantly higher detection rate observed in studies using at least one outflow-tract view or color-flow Doppler imaging (both P < 0.0001). Different types of cardiac anomaly were not equally amenable to detection on first-trimester ultrasound.

CONCLUSIONS

First-trimester ultrasound examination of the fetal heart allows identification of over half of fetuses affected by major cardiac pathology. Future first-trimester screening programs should follow structured anatomical assessment protocols and consider the introduction of outflow-tract views and color-flow Doppler imaging, as this would improve detection rates of fetal cardiac pathology. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The diagnostic value of the early extended fetal heart examination at 13 to 14 weeks gestational age in a high-risk population

BACKGROUND

Congenital heart disease (CHD) is the most common congenital malformation that affects high-risk populations. A more definite heart diagnosis in the first trimester should be provided to guide clinical treatment. The study aim was to evaluate the diagnostic precision of the early extended fetal heart examination (EFHE) that includes abdominal situs view, four-chamber view (4CV), left ventricular outflow tract view (LVOT), right ventricular outflow tract view (RVOT), 3-vessel and tracheal view (3VT), ductal arch view, and the aortic arch view in the detection of CHD at the gestational age (GA) 13 to 14 weeks in a population with high risks.

METHODS

This study was a diagnostic test study. EFHE was performed by transabdominal sonography in women at GA 13 to 14 weeks with singleton pregnancies who were at high risk for CHD. The risk of CHD was determined by family history of CHD, rubella infection, metabolic disorders, exposure to teratogens, conception by in-vitro fertilization (IVF), increased nuchal translucency (NT) thickness, abnormal obstetric ultrasound, etc. The operator had more than 5 years of experience in first-trimester scans and fetal echocardiography. Early scans were compared with a fetal echocardiography in the second trimester (16-24 weeks).

RESULTS

EFHE was performed, and the pregnancy outcomes were obtained in 234 single pregnancies with a high risk of CHD. The average crown-rump length (CRL) was (76.17±7.09) mm. CHD was diagnosed in 43 cases by EFHE; 10 of these cases were misdiagnosed, and 2 cases were missed. Four cases were inconsistent in the main diagnosis of CHD. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and kappa coefficient (Ko) value of EFHE in diagnosing CHD by type and severity was 84.6% [95% confidence interval (CI), 69.5-94.1%], 96.9% (95% CI, 93.4-98.9%), 84.6% (95% CI, 69.5-94.1%), 96.9% (95% CI, 93.4-98.9%), and 0.82 (P<0.001), respectively.

CONCLUSIONS

EFHE can work as a diagnose examination for most major CHD cases at GA 13 to 14 weeks by an experienced operator; Therefore, this diagnostic system for fetal CHD may be applied in the first trimester. The study has been registered in the Chinese Clinical Trial Registry (www.chictr.org.cn). The registration number is ChiCTR2000038451.

Prenatal incidence of isolated right aortic arch and double aortic arch

OBJECTIVE

To define the incidence of variants of aortic arch sidedness in fetuses undergoing routine first trimester ultrasound examination.

METHODS

The data for this study were derived from prospective routine ultrasound examination at 11+0 to 13+6 weeks' gestation in singleton pregnancies examined in a local population between January 2014 and March 2018. We examined the incidence of isolated right aortic arch (RAA) and double aortic arch (DAA) in the local, screened population and compared the groups with and without these abnormalities.

RESULTS

The study population of 33,202 pregnancies included 18 (5.4 per 10,000) cases with isolated RAA and 5 (1.5 per 10,000) with DAA. In the group with isolated RAA or DAA, compared to those without, the median maternal age was higher and the incidence of conceptions from in vitro fertilization (IVF) was eight-fold higher. The prevalence of 22q11microdeletion was 5% in patients with RAA from this local population.

CONCLUSIONS

The incidence of isolated RAA and DAA in a local population undergoing routine first-trimester ultrasound examination is 2-3-fold higher than that reported in postnatal studies and the risk for these abnormalities is substantially increased in fetuses conceived by IVF.

Cardiac axis evaluation as a screening method for detecting cardiac abnormalities in the first trimester of pregnancy

Congenital cardiac abnormalities refer to especially anatomic malformations of the heart that normally occur during fetal heart development, before eight weeks after conception. Aim: The aim is to investigate the association between cardiac axis and congenital heart abnormalities for a potential underline clinical application of cardiac axis evaluation during detection by abnormalities at the time of first trimester ultrasound. It is known that aneuploids can be associated in almost half of cases with cardiac abnormalities, so the angle of the cardiac axis could be a potential indirect marker for the detection of aneuploids in the first trimester of pregnancy. Being easy to obtain, from the cross-section at the chest level with the visualization of the four chambers, does not require additional sections to those provided in the current guides, we aim to prove its usefulness in diagnosing aneuploids and congenital cardiac abnormalities along with the translucent nuchal flow, at the level of the venous duct and the presence of tricuspid regurgitation. Conclusions: Cardiac axis has a higher value for the detection of congenital cardiac abnormalities with respect to the nuchal translucency, tricuspid regurgitation and inverted A wave at the level of the venous duct.

Reference Ranges for Pulsed-Wave Doppler of the Fetal Cardiac Inflow and Outflow Tracts from 13 to 36 Weeks' Gestation

BACKGROUND

Doppler assessment of ventricular filling and outflow tract velocities is an integral part of fetal echocardiography, to assess diastolic function, systolic function, and outflow tract obstruction. There is a paucity of prospective data from a large sample of normal fetuses in the published literature. The authors report reference ranges for pulsed-wave Doppler flow of the mitral valve, tricuspid valve, aortic valve, and pulmonary valve, as well as heart rate, in a large number of fetuses prospectively examined at a single tertiary fetal cardiology center.

METHODS

The study population comprised 7,885 fetuses at 13 to 36 weeks' gestation with no detectable abnormalities from pregnancies resulting in normal live births. Prospective pulsed-wave Doppler blood flow measurements were taken of the mitral, tricuspid, aortic, and pulmonary valves. The fetal heart rate was recorded at the time of each assessment. Regression analysis, with polynomial terms to assess for linear and nonlinear contributors, was used to establish the relationship between each measurement and gestational age.

RESULTS

The measurement for each cardiac Doppler measurement was expressed as a Z score (difference between observed and expected values divided by the fitted SD corrected for gestational age) and percentile. Analysis included calculation of gestation-specific SDs. Regression equations are provided for the cardiac inflow and outflow tracts.

CONCLUSIONS

This study establishes reference ranges for fetal cardiac Doppler measurements and heart rate between 13 to 36 weeks' gestation that may be useful in clinical practice.

Tetralogy of Fallot and Outlet Ventricular Septal Defect with Anterior Malalignment Detected at Early Fetal Echocardiography

OBJECTIVES

To examine the evolution of tetralogy of Fallot (TOF) and outlet ventricular septal defect (VSD) with anterior malalignment (am) from the initial diagnosis at early fetal echocardiography through the gestation and to evaluate the impact of the first-trimester scan on the outcome.

METHODS

We identified cases of TOF or outlet VSD with am diagnosed before 16 weeks' gestation. For all cases, prenatal data and pregnancy outcomes were evaluated. In continuing pregnancies, the evolution in severity of the disease was assessed.

RESULTS

Fifty-one fetuses with TOF or outlet VSD with am were diagnosed at early fetal echocardiography. Parents opted for termination of pregnancy in all 23 cases associated with additional anomalies. In 2 of 28 continuing pregnancies, there was an intrauterine death. In the remaining 26, there was progression in severity in 7 (by 20-22 weeks in 3 cases and during the third trimester in the remaining 4).

CONCLUSIONS

TOF and outlet VSD with am diagnosed before 16 weeks' gestation can progress in severity throughout pregnancy in over one-quarter of cases. In addition, a high proportion of cases diagnosed in the first trimester may have associated extracardiac anomalies, with a significant impact on clinical management and on the rate of early termination of pregnancy.

First trimester fetal echocardiography limitations and its expected clinical values

BACKGROUND

Fetal cardiac activity could be observed between 6th and 7th gestational weeks, early performance of fetal echocardiography could be implemented to screen for fetal heart disease. The effectiveness of early first trimester fetal echocardiography has not been adequately investigated, especially with modern sonographic technological advances. The purpose of the study is to evaluate the capability to visualize fetal cardiac structures within the first trimester as early as 10th gestational weeks and to elucidate the value of using color Doppler in visualization of cardiac structures within early gestation. A prospective clinical trial conducted on 150 study subjects, 44 of them were twin gestations. Cases were fully assessed by fetal echocardiographic examination from 10th gestational week to 13 gestational weeks in a sequential manner weekly. The research study was conducted at cardiology department fetal unit in one of the tertiary hospitals.

RESULTS

Four chamber view was mostly visualized from 12 gestational weeks, whereas cardiac axis was fully visualized in all cases from 12 gestational weeks; on the other hand, IVC assessment by 2D was satisfactorily visualized in 78.26% of cases and by color Doppler in 82.61% of cases at 13 gestational weeks, pulmonary veins were visualized in 21.74% of cases by 2D and 43.5% of cases by color Doppler at 13 gestational weeks, and interestingly, ventricular inflows were satisfactorily visualized in almost all cases from 10th gestational weeks.

CONCLUSIONS

First trimester fetal echo is an outstanding enhancement in management pathways of cases susceptible to have fetal cardiac abnormalities permitting early detection of structural cardiac anomalies triggering a cascade of scanning for extra cardiac anomalies to aid in evaluation and assessment of the best management course for those affected cases.

Fetal heart examination at the time of 13 weeks scan: a 5 years' prospective study

Objective To evaluate our ability in classifying the fetal heart as normal or abnormal during the 1st trimester scan through fetal cardiac examination and determining the best time for this examination. Methods This was a prospective study performed on 3240 pregnant women to examine the fetal heart. Four chambers view and ventricular outflow tracts were mainly examined during the scan. We used grayscale and color mapping in the diagnosis. Color Doppler was used if additional information was needed, and all patients were rescanned during the 2nd trimester to confirm or negate our diagnosis. Results The cardiac findings were normal at both scans in 3108 pregnancies. The same cardiac abnormality was detected at both scans in 79 cases. In 36 cases there was false-positive diagnosis at the early scan; in 20 of these cases, there were mildly abnormal functional findings early in pregnancy with no abnormality found later. In 17 fetuses, there was discordance between the early and later diagnosis due to missed or incorrect diagnoses. The best time to do fetal heart examination during 1st trimester is between 13 and 13 + 6 weeks. Conclusion A high degree of accuracy in the identification of congenital heart disease (CHD) can be achieved by a 1st trimester fetal echocardiography.

Initial Experience of Superb Microvascular Imaging for Key Cardiac Views in Foetal Assessment before 15 Weeks Gestation

BACKGROUND

In the first trimester, ultrasound confirmation of normal or abnormal cardiac anatomy is difficult. B-mode and colour flow Doppler (CFD) are used to assess the foetal heart. Superb microvascular imaging (SMI) can visualise blood flow within the heart and vessels in early gestation.

OBJECTIVE

We report an initial experience of SMI for visualisation of normal and abnormal cardiac anatomy in the first trimester.

METHODS

Transabdominal foetal echocardiography was performed between 11 + 6 and 14 + 3 weeks (Aplio 500 US system, Toshiba Medical Systems, Tokyo, Japan) from January 2017 to December 2017. All scans were performed at a tertiary foetal cardiology unit. To assess the potential utility of the technique for early gestation screening, normal scans were reviewed by foetal medicine trainees with respect to the B-mode, CFD and SMI. Three key views were selected to compare modalities: the 4-chamber view, outflow tracts and the 3-vessel and trachea view (VTV). Visualisation rates of key echocardiographic features of significant cardiac abnormalities by SMI were reviewed.

RESULTS

Fifty-five normal echocardiograms and 34 cardiac abnormalities were included. In the normal heart, when B-mode, CFD and SMI were assessed separately, SMI had the highest rate of visualisation of 4-chamber, outflow tracts and 3-VTV (93, 85 and 83%, respectively). Intra-observer reliability was moderate for SMI of the 3 standard views (kappa 1, 0.64 and 0.64); inter-observer for 4-chamber and outflow tract views was moderate (kappa 0.64 and 0.77). In 29/34 abnormal cases, SMI showed key features, enhancing greyscale visualisation.

CONCLUSION

SMI has potential to become a useful, complementary modality for early foetal echocardiography. Further prospective studies are warranted to establish the place of the technique in assessment of the first trimester foetal heart.

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.

Prenatal diagnosis and clinical implications of an apparently isolated right aortic arch

OBJECTIVE

To define the associations of a prenatally diagnosed, apparently isolated right aortic arch (RAA) with chromosomal or genetic abnormalities and tracheal compression.

METHODS

This was a retrospective study of apparently isolated RAA assessed by fetal cardiologists and fetal medicine specialists at Kings College Hospital, London between 2000 and 2017.

RESULTS

The search identified 138 cases of apparently isolated RAA. Invasive testing was performed in 75, and chromosomal or genetic anomalies were identified in 16 (22%), and the most common was 22q11 microdeletion. An aberrant left subclavian artery was seen in 51% of cases. Symptoms of a vascular ring were present in 24 of 97 (25%) children who were reviewed after birth. Bronchoscopy was performed in 33 children, and significant tracheal compression was diagnosed in 28, including 18 of 19 symptomatic and 10 of 14 asymptomatic children.

CONCLUSIONS

An apparently isolated RAA is associated with a high incidence of chromosomal or genetic abnormalities and a high incidence of tracheal compression in symptomatic and asymptomatic patients. Prenatal counselling for genetic associations and postnatal airway assessment in the context of the vascular anatomy is recommended.

Contribution of the Fetal Cardiac Axis and V-Sign Angle in First-Trimester Screening for Major Cardiac Defects

OBJECTIVE

To estimate the potential value of fetal assessment for the cardiac axis (CAx) and V-sign angle (VSA) in the first trimester in the prediction of fetal major cardiac defects.

METHODS

A cohort study was conducted from December 2015 to June 2016. Patients with singleton pregnancies and crown-rump length from 45 to 84 mm were recruited to undergo nuchal translucency sonography. The CAx on the 4-chamber view and the VSA on the 3-vessel and trachea view with Doppler mapping were measured. The estimated performance of different combinations of increased fetal nuchal translucency, CAx, and VSA in screening for major cardiac defects was examined.

RESULTS

The study population of fetuses included 30 fetuses with major cardiac defects and 1538 normal fetuses. The CAx and VSA were 30° to 60° and 30° to 40°, respectively, according to the 2.5th and 97.5th percentiles in normal fetuses. When cases of isolated septal wall defects and an isolated right aortic arch were excluded, nuchal translucency above the 95th percentile, an abnormal CAx, and an abnormal VSA were observed in 63.3% (19 of 30), 63.3% (19 of 30), and 66.7% (20 of 30) of fetuses with major cardiac defects, respectively, and in 4.6% (71 of 1538), 2.0% (30 of 1538), and 5.6% (86 of 1538) of those without cardiac defects. Either an abnormal CAx or VSA was found in 93.3% (28 of 30) of the fetuses with cardiac defects and in 7.3% (113 of 1538) of those without cardiac defects.

CONCLUSION

Assessment of the CAx and VSA is helpful in defining a population at risk for major cardiac defects in the first trimester.

Applicability of Standardized Early Fetal Heart Examination in the Obese Population

OBJECTIVE

This study aimed to evaluate the impact of obesity on early evaluation of fetal cardiac landmarks using a standardized examination method at the time of nuchal translucency scan.

METHODS

This was a cross-sectional study of an ongoing prospective cohort at high risk for congenital heart defects. We used a standardized examination protocol using 2-dimensional sonography with power Doppler in the evaluation of fetal cardiac landmarks consisting of 4-chamber view, outflow tract relationship, and transverse arches view. The study population was stratified based on maternal body mass index into nonobese (<30 kg/m² ) and obese (≥30 kg/m² ). Groups were compared in terms of satisfactory evaluation of fetal cardiac landmarks, transvaginal sonography use, and scan times required for the evaluations. Subanalysis was performed by further categorizing obesity into nonmorbid obesity (30.0-39.9 kg/m² ) and morbid obesity (≥40 kg/m² ).

RESULTS

A total of 190 patients were evaluated. Of these, 48.4% (n = 92) were obese. The most common indication for fetal cardiac assessment was maternal pregestational diabetes mellitus (42.6%). Transvaginal sonography was utilized in one nonobese woman (1.4%) and 11 obese women (12%) (P = .002). The satisfactory evaluation of 4-chamber view, outflow tract relationship, transverse arches view, and all views were not significantly different between groups (P > .05). The scan time was about 5 minutes longer in the obese group compared with nonobese group (P = .020).

CONCLUSIONS

Obesity does not hamper early evaluation of fetal cardiac landmarks around the time of nuchal translucency scan. However, obese patients are more likely to require transvaginal examinations.

Three-dimensional visualisation of the fetal heart using prenatal MRI with motion-corrected slice-volume registration: a prospective, single-centre cohort study

BACKGROUND

Two-dimensional (2D) ultrasound echocardiography is the primary technique used to diagnose congenital heart disease before birth. There is, however, a longstanding need for a reliable form of secondary imaging, particularly in cases when more detailed three-dimensional (3D) vascular imaging is required, or when ultrasound windows are of poor diagnostic quality. Fetal MRI, which is well established for other organ systems, is highly susceptible to fetal movement, particularly for 3D imaging. The objective of this study was to investigate the combination of prenatal MRI with novel, motion-corrected 3D image registration software, as an adjunct to fetal echocardiography in the diagnosis of congenital heart disease.

METHODS

Pregnant women carrying a fetus with known or suspected congenital heart disease were recruited via a tertiary fetal cardiology unit. After initial validation experiments to assess the general reliability of the approach, MRI data were acquired in 85 consecutive fetuses, as overlapping stacks of 2D images. These images were then processed with a bespoke open-source reconstruction algorithm to produce a super-resolution 3D volume of the fetal thorax. These datasets were assessed with measurement comparison with paired 2D ultrasound, structured anatomical assessment of the 2D and 3D data, and contemporaneous, archived clinical fetal MRI reports, which were compared with postnatal findings after delivery.

FINDINGS

Between Oct 8, 2015, and June 30, 2017, 101 patients were referred for MRI, of whom 85 were eligible and had fetal MRI. The mean gestational age at the time of MRI was 32 weeks (range 24-36). High-resolution (0·50-0·75 mm isotropic) 3D datasets of the fetal thorax were generated in all 85 cases. Vascular measurements showed good overall agreement with 2D echocardiography in 51 cases with paired data (intra-class correlation coefficient 0·78, 95% CI 0·68-0·84), with fetal vascular structures more effectively visualised with 3D MRI than with uncorrected 2D MRI (657 [97%] of 680 anatomical areas identified vs 358 [53%] of 680 areas; p<0·0001). When a structure of interest was visualised in both 2D and 3D data (n=358), observers gave a higher diagnostic quality score for 3D data in 321 (90%) of cases, with 37 (10%) scores tied with 2D data, and no lower scores than for 2D data (Wilcoxon signed rank test p<0·0001). Additional anatomical features were described in ten cases, of which all were confirmed postnatally.

INTERPRETATION

Standard fetal MRI with open-source image processing software is a reliable method of generating high-resolution 3D imaging of the fetal vasculature. The 3D volumes produced show good spatial agreement with ultrasound, and significantly improved visualisation and diagnostic quality compared with source 2D MRI data. This freely available combination requires minimal infrastructure, and provides safe, powerful, and highly complementary imaging of the fetal cardiovascular system.

FUNDING

Wellcome Trust/EPSRC Centre for Medical Engineering, National Institute for Health Research.

Early fetal echocardiography

OBJECTIVES

To explore the technical aspects and clinical utility of early fetal echocardiography and screening of the fetal heart in early pregnancy. Also, to document differences in cardiac structure and function which can be demonstrated in the late first/early second trimesters.

METHODS

In addition to summarizing our own experiences of late first/early second trimester fetal echocardiography, we reviewed the literature to explore clinical indications for, technical aspects, safety, accuracy, strengths and weaknesses of early fetal echocardiography.

RESULTS

In the current era, an increasing number of fetuses are identified as being at risk of congenital heart disease from as early as the late first trimester. In experienced hands, early fetal echocardiography can pick up a high proportion of congenital heart disease with good reliability for the majority of lesions. Early fetal echocardiography is relatively poor at assessing pulmonary veins, the atrioventricular valves and lesions that typically occur later or progress during the course of pregnancy. There is increasing interest in widespread implementation of an early obstetric anomaly screen which includes an assessment of the fetal heart for all pregnancies. There are a variety of hemodynamic differences in the late first/early second trimester compared with later in pregnancy.

CONCLUSION

Early fetal echocardiography is has become an established tool for detection of congenital heart disease. It affords opportunities to learn about the true spectrum and progression of congenital heart disease in-utero. Operators should be mindful of safety issues, technical aspects and hemodynamic findings which differ when performing echocardiograms at this stage of pregnancy.

"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.

Fetal Anatomic Imaging Between 11 and 14 Weeks Gestation

Fetal imaging between 11 and 14 weeks is a standard component of prenatal risk assessment for aneuploidy. Evaluating the fetus during this gestational age window provides the opportunity to reliably examine anatomic structures. Using a defined imaging protocol, approximately 50% of major abnormalities can be detected. Some abnormalities should almost always be detected, some may be detected on occasion and others are not currently detectable. Imagers must be familiar with embryologic patterns of development and natural history of anomalies. Patients must be informed of the limitations of early anatomic evaluation. Currently, early anatomic evaluation does not replace the standard second trimester evaluation.

Prenatal screening of fetal ventriculoarterial connections: benefits of 4D technique in fetal heart imaging

Background

Identification of prenatal ventriculoarterial connections in fetuses with conotruncal anomalies (CTA) remains one of the greatest challenges for sonographers performing screening examinations. Herein, we propose a novel protocol of 4D volume analysis that identifies ventriculoarterial connections and evaluate its clinical utility in routine screenings.

Methods

Twenty-nine cases of transposition of the great arteries (TGA), 22 cases of double-outlet right ventricle (DORV), 36 cases of tetralogy of Fallot (TOF), 14 cases of truncus arteriosus (TCA), and randomly selected 70 normal fetuses were reviewed in this study. All cases were evaluated using 2D data alone (2D method), post-processing volumes with no exact algorithm (4D-1 method), or with the proposed algorithm (4D-2 method), or using the 2D and 4D data together (combined method). Comparisons were made to evaluate the detection rate of ventriculoarterial connections for these different methods.

Results

During 18–28 gestational weeks, the detection rate of 4D-2 modality was satisfactory. The detection rate of the combined method was significantly higher than 2D method in the identification of TGA, TOF, and TCA. The detection rate of 4D-1 method was significantly lower than 4D −2 modality for CTA fetuses. During late pregnancy, the detection rate for both 4D modalities was very low due to the poor quality of the 4D volumes.

Conclusions

We proposed a detailed protocol, which allowed the examiner to identify fetal ventriculoarterial connections by 4D volumes. Inclusion of blood information into the volumes improved diagnosis. Our findings suggest that the incorporation of 4D STIC into routine screenings could improve the detection for TGA, TOF, and TCA.

Electronic supplementary material

The online version of this article (doi:10.1186/s12947-017-0108-5) contains supplementary material, which is available to authorized users.

Basic heart examination: feasibility study of first-trimester systematic simplified fetal echocardiography

OBJECTIVE

First-trimester fetal cardiac screening examinations in low-risk populations should not have to meet the specifications required for high-risk populations. Our aim was to evaluate a simplified fetal echocardiographic ('basic heart') examination for early detection of severe congenital heart defects in a low-risk population.

METHODS

This was a first-trimester national 'flash study', performed over a 2-week period. Each observer was requested to perform simplified echocardiography without modifying the time and methods deemed necessary for the routine first-trimester ultrasound examination, in fetuses with crown-rump length between 45 and 84 mm. This basic heart assessment used targeted cross-sections of the four-chamber view (4CV) and of the three vessels and trachea (3VT) view, using color and/or directional power Doppler. All examinations were then reviewed offline and scored for quality by a qualified expert.

RESULTS

Sixty observers performed a total of 597 first-trimester ultrasound examinations, each performing an average of 10 (range, 1-26) procedures. Examinations were conducted transabdominally (79%; 472/597), transvaginally (3%; 17/597) or both (18%; 108/597). In 8% (45/597) of cases, the fetal back was anterior, in 18% (108/597) it was on the left side, in 63% (377/597) it was posterior and in 11% (67/597) it was on the right side. It became clear during scoring by the expert that, unlike the Herman quality score for nuchal translucency measurement, it was difficult to assess the quality of these images without taking into account normality of the heart itself. Analysis of scores showed that the 4CV was obtained successfully and was deemed normal in 86% (512/597) of the patients, in 7% (41/597) it was deemed technically infeasible and in 7% (44/597) it was deemed feasible but atypical, which may have been due to the presence of an abnormality or to poor quality of the image. The 3VT view was obtained successfully and was normal in 79% (472/597) of the patients, in 13% (78/597) it was technically infeasible and in 8% (47/597) it was deemed feasible but atypical. Both the 4CV and the 3VT view were obtained successfully and were normal in 73% (435/597) of patients.

CONCLUSION

It is possible for a trained operator to perform simplified fetal echocardiography during the routine first-trimester ultrasound examination in a low-risk population. In most cases, our basic heart examination can be used to reassure parents or identify potential problems to be clarified as early as possible in the second trimester. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

How to Acquire Cardiac Volumes for Sonographic Examination of the Fetal Heart: Part 1

Four-dimensional sonography with spatiotemporal image correlation (STIC) technology allows acquisition of a fetal cardiac volume data set and displays a cine loop of a complete single cardiac cycle in motion. Part 1 of this 2-part article reviews STIC technology and its features, the importance of operator training/experience, and acquisition of high-quality STIC volumes, as well as factors that affect STIC volume acquisition rates. We also propose a detailed and practical stepwise approach to performing 4-dimensional sonography with STIC and begin herein by providing general recommendations. Part 2 will discuss specifics of the approach, along with how to determine whether such volumes are appropriate for analysis.

Prenatal Associated Features in Fetuses Diagnosed with an Aberrant Right Subclavian Artery

Objective: The objective of this study was to determine the frequency and the nature of associated anomalies, especially malformations and chromosome abnormalities, in a population of fetuses with an aberrant right subclavian artery (ARSA). Materials and Methods: This is a 7-year descriptive study. All patients whose fetus had an ARSA diagnosed by ultrasound performed during the 1st, 2nd, or 3rd trimester of pregnancy were included, regardless of their risk of chromosomal abnormalities. Results: Between May 2007 and April 2014, an ARSA was diagnosed in 120 fetuses. The outcome was found in 108 cases (90%). ARSA was an isolated finding in 54/108 cases (50%). In 20% (22/108) of the fetuses, chromosomal abnormalities were detected. No chromosomal abnormalities were found in fetuses with an isolated ARSA. 82% (18/22) of chromosomal abnormalities were usual, such as trisomies 21 and 18, monosomy X, and 22q11.2 deletion. 21% (23/108) of the fetuses presenting an ARSA were associated with having a congenital heart disease. Conclusion: The presence of an isolated ARSA is a condition rarely associated with a chromosomal abnormality. The decision to perform an invasive karyotyping procedure under such circumstances or not may be made according to the principle of parental autonomy after extensive counselling and mostly a thorough assessment of the fetus.

Early second trimester transvaginal ultrasound anomaly scan does not cause adverse perinatal outcome

OBJECTIVE

During an early second-trimester transvaginal ultrasound anomaly scan, pressure is applied to the uterus, and the fetus is often rotated manually to allow scanning of its various organs. This study was designed to determine if performing a transvaginal ultrasound anomaly scan during the early second trimester of pregnancy is associated with adverse perinatal outcome or cord entanglement.

METHODS

During the 4.5year study period we prospectively collected cases of routine ultrasound scans at 14-17weeks gestation performed as anomaly screening, together with perinatal outcome. The study population consisted of 164 women who underwent a transvaginal approach, and the control population consisted of 224 women in which a transabdominal approach was used. Data on perinatal parameters was collected from delivery charts from the four local hospitals.

RESULTS

There were more operative deliveries (vaginal or Cesarean) in the transvaginal scan group (32% vs. 23%, p=0.05). However, on multiple logistic regression analysis vaginal scans were not associated with increased operative delivery rates with an adjusted odds ratio of 1.47 and a 95% confidence interval of 0.85-2.54. There were no other clinically significant differences in perinatal outcomes, or in cord entanglement.

CONCLUSIONS

Transvaginal ultrasound anomaly scan conducted in the early second trimester of pregnancy is a safe procedure for the fetus.