Fetal cardiac screening and variation in prenatal detection rates of congenital heart disease: why bother with screening at all?

Applications of artificial intelligence-powered prenatal diagnosis for congenital heart disease

Artificial intelligence (AI) has made significant progress in the medical field in the last decade. The AI-powered analysis methods of medical images and clinical records can now match the abilities of clinical physicians. Due to the challenges posed by the unique group of fetuses and the dynamic organ of the heart, research into the application of AI in the prenatal diagnosis of congenital heart disease (CHD) is particularly active. In this review, we discuss the clinical questions and research methods involved in using AI to address prenatal diagnosis of CHD, including imaging, genetic diagnosis, and risk prediction. Representative examples are provided for each method discussed. Finally, we discuss the current limitations of AI in prenatal diagnosis of CHD, namely Volatility, Insufficiency and Independence (VII), and propose possible solutions.

Pulse Oximetry Screening for Critical Congenital Heart Defects in Newborn Babies

Pulse oximetry screening (POS) was first described over 20 years ago. However, in recent years, major clinical trials have demonstrated consistent test accuracy for the detection of critical congenital heart defects (CCHD). International uptake of POS has progressed well over the last 10 years with most major high-income countries now recommending screening. This review describes the evidence base which has led to this, the current debate regarding choice of screening algorithm, and the future areas for further research.

Trend of fetal echocardiography use and comparison of medical costs for congenital heart disease treatment based on fetal echocardiography use in a Korean single center

Background

The rate of the prenatal diagnosis of congenital heart disease is increasing along with advances in fetal echocardiography techniques. Here, we aimed to investigate the trend of the use of fetal echocardiography over time and to compare the medical costs of congenital heart disease treatment according to whether fetal echocardiography was performed.

Methods

We reviewed our hospital's database, and patients who underwent the first surgery for congenital heart disease within 30 days of birth during 2005-2007, 2011-2013, and 2017-2019 were included. The severity of congenital heart disease diagnosed in each case was evaluated according to The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Scores (STS-EACTS Mortality Scores) and Mortality Categories (STAT Mortality Categories).

Results

In total, 375 patients were analyzed, and fetal echocardiography use increased significantly after the 2010s compared with in 2005-2007 (19.1% vs. 39%, p = 0.032 in Mortality Category 1-3; 15.5% vs. 69.5%, p = 0.000 in Mortality Category 4-5). Additionally, the mean STS-EACTS Mortality Score was higher in prenatally diagnosed patients than in postnatally diagnosed patients (2.287 vs. 1.787, p = 0.001). In the recent period, there was no significant difference in hospitalization durations and medical costs according to whether or not fetal echocardiography was performed.

Conclusions

This single center study showed the use of fetal echocardiography is increasing. Further, prenatal diagnosis with fetal echocardiography causing no differences in medical costs in recent years. Therefore, we suggest that fetal echocardiography can be applied more widely without increasing the economic burden.

The electrical heart axis in fetuses with congenital heart disease, measured with non-invasive fetal electrocardiography

OBJECTIVES

To determine if the electrical heart axis in different types of congenital heart defects (CHD) differs from that of a healthy cohort at mid-gestation.

METHODS

Non-invasive fetal electrocardiography (NI-fECG) was performed in singleton pregnancies with suspected CHD between 16 and 30 weeks of gestation. The mean electrical heart axis (MEHA) was determined from the fetal vectorcardiogram after correction for fetal orientation. Descriptive statistics were used to determine the MEHA with corresponding 95% confidence intervals (CI) in the frontal plane of all fetuses with CHD and the following subgroups: conotruncal anomalies (CTA), atrioventricular septal defects (AVSD) and hypoplastic right heart syndrome (HRHS). The MEHA of the CHD fetuses as well as the subgroups was compared to the healthy control group using a spherically projected multivariate linear regression analysis. Discriminant analysis was applied to calculate the sensitivity and specificity of the electrical heart axis for CHD detection.

RESULTS

The MEHA was determined in 127 fetuses. The MEHA was 83.0° (95% CI: 6.7°; 159.3°) in the total CHD group, and not significantly different from the control group (122.7° (95% CI: 101.7°; 143.6°). The MEHA was 105.6° (95% CI: 46.8°; 164.4°) in the CTA group (n = 54), -27.4° (95% CI: -118.6°; 63.9°) in the AVSD group (n = 9) and 26.0° (95% CI: -34.1°; 86.1°) in the HRHS group (n = 5). The MEHA of the AVSD and the HRHS subgroups were significantly different from the control group (resp. p = 0.04 and p = 0.02). The sensitivity and specificity of the MEHA for the diagnosis of CHD was 50.6% (95% CI 47.5% - 53.7%) and 60.1% (95% CI 57.1% - 63.1%) respectively.

CONCLUSION

The MEHA alone does not discriminate between healthy fetuses and fetuses with CHD. However, the left-oriented electrical heart axis in fetuses with AVSD and HRHS was significantly different from the control group suggesting altered cardiac conduction along with the structural defect.

TRIAL REGISTRATION

Clinical trial registration number: NL48535.015.14.

Evaluation of the Association between Fetal Cardiac Disorders with Choroid Plexus Cyst in Fetuses

Choroid plexus cysts (CPCs) are often transient and benign findings observed in pregnancy screenings. This study aimed to examine the association between the frequency of congenital heart diseases and the detection of CPCs. In this prospective case-control study, pregnant mothers with no predisposing risk factors for the development of fetal cardiac abnormalities were eligible for entry. Based on the presence or absence of CPCs on ultrasound, the enrolled fetuses were divided into two groups. All patients (n = 100) underwent two-dimensional and color Doppler echocardiography to identify potential cardiac anomalies. Overall, CPCs were detected in 53 enrolled fetuses, and the remainder were enrolled as controls (n = 47). Pathological findings, such as echogenic intracardiac focus (EIF), ductal spasm, atrial septal defect (ASD), pericardial effusion, cardiomyopathy, and congenital heart disease were found in neither group. In the CPC group, two mild and six trivial cases of tricuspid regurgitation (TR) were detected. In the controls, five cases of trivial TR were identified. In conclusion, the presence of CPCs was not associated with significant functional or structural fetal cardiac abnormalities, which may be due to altered developmental mechanisms.

New born pulse oximetry screening: A global perspective

The possibility of pulse oximetry screening (POS) for congenital heart defects was first described over 20 years ago. Since then, an accumulation of research evidence and clinical practice experience has established POS as an important test to detect critical congenital heart defects (CCHDs). POS meets the criteria for universal screening and professional bodies around the globe have recommended universal POS. Many countries have already adopted POS while several others are working towards its implementation. In low and low-middle-income countries (LLMIC), POS has the additional potential for reducing morbidity and mortality from neonatal sepsis. This review summarises the evidence for POS and looks at current global uptake and different approaches to the implementation of POS.

Urine metabolomic biomarkers for prediction of isolated fetal congenital heart defect

OBJECTIVE

To identify maternal second and third trimester urine metabolomic biomarkers for the detection of fetal congenital heart defects (CHDs).

STUDY DESIGN

This was a prospective study. Metabolomic analysis of randomly collected maternal urine was performed, comparing pregnancies with isolated, non-syndromic CHDs versus unaffected controls. Mass spectrometry (liquid chromatography and direct injection and tandem mass spectrometry, LC-MS-MS) as well as nuclear magnetic resonance spectrometry, ¹H NMR, were used to perform the analyses between 14 0/7 and 37 0/7 weeks gestation. A total of 36 CHD cases and 41 controls were compared. Predictive algorithms using urine markers alone or combined with, clinical and ultrasound (US) (four-chamber view) predictors were developed and compared.

RESULTS

A total of 222 metabolites were identified, of which 16 were overlapping between the two platforms. Twenty-three metabolite concentrations were found in significantly altered in CHD gestations on univariate analysis. The concentration of methionine was most significantly altered. A predictive algorithm combining metabolites (histamine, choline, glucose, formate, methionine, and carnitine) plus US four-chamber view achieved an AUC = 0.894; 95% CI, 0814-0.973 with a sensitivity of 83.8% and specificity of 87.8%. Enrichment pathway analysis identified several lipid related pathways that are dysregulated in CHD, including phospholipid biosynthesis, phosphatidylcholine biosynthesis, phosphatidylethanolamine biosynthesis, and fatty acid metabolism. This could be consistent with the increased risk of CHD in diabetic pregnancies.

CONCLUSIONS

We report a novel, noninvasive approach, based on the analysis of maternal urine for isolated CHD detection. Further, the dysregulation of lipid- and folate metabolism appears to support prior data on the mechanism of CHD.

Ventricular septal defect: diagnosis and treatments in the neonates: a systematic review

BACKGROUND

Medical advancements have encouraged minimally invasive surgical repair of congenital heart defects such as ventricular septal defects (VSDs), and the diagnostic process can now be carried out using non-traditional techniques such as pulse oximetry. This, in turn, has improved clinical outcomes with reduced complication rates post-surgery. However, the variations in type of VSDs, age of patient, comorbidities, and access to closure devices may limit the efficacy of surgical advancements.

METHODS

Articles were identified amongst Scopus, MEDLINE, and PubMed using various relevant search strings using PRISMA guidelines. Of the 115 articles initially extracted, 10 were eventually reviewed after duplicates and irrelevant studies were removed.

RESULTS

Of the 24 eligible articles, 10 papers were selected for analysis. Minimally invasive approaches to VSD repair was associated with satisfactory short-term outcomes when compared to open repair. For diagnosis of congenital VSD, whilst recent advances such as pulse oximetry method and genome analysis are more sensitive, the limited availability and access to such investigatory methods must be recognised.

CONCLUSION

Pulse oximetry and fetal echocardiography are established non-invasive diagnostic tools for VSD. The recent advances in minimally invasive treatment options including periventricular approach and transcatheter techniques have improved patient outcomes, yet at the expense of higher residual rates. Careful patient selection for each technique and follow-up should be planned through multidisciplinary team meetings.

Noninvasive screening for congenital heart defects using a serum metabolomics approach

OBJECTIVE

Heart anomalies represent nearly one-third of all congenital anomalies. They are currently diagnosed using ultrasound. However, there is a strong need for a more accurate and less operator-dependent screening method. Here we report a metabolomics characterization of maternal serum in order to describe a metabolomic fingerprint representative of heart congenital anomalies.

METHODS

Metabolomic profiles were obtained from serum of 350 mothers (280 controls and 70 cases). Nine classification models were built and optimized. An ensemble model was built based on the results from the individual models.

RESULTS

The ensemble machine learning model correctly classified all cases and controls. Malonic, 3-hydroxybutyric and methyl glutaric acid, urea, androstenedione, fructose, tocopherol, leucine, and putrescine were determined as the most relevant metabolites in class separation.

CONCLUSION

The metabolomic signature of second trimester maternal serum from pregnancies affected by a fetal heart anomaly is quantifiably different from that of a normal pregnancy. Maternal serum metabolomics is a promising tool for the accurate and sensitive screening of such congenital defects. Moreover, the revelation of the associated metabolites and their respective biochemical pathways allows a better understanding of the overall pathophysiology of affected pregnancies.

Pulse oximetry screening for critical congenital heart defects in Ontario, Canada: a cost-effectiveness analysis

OBJECTIVE

Previously conducted cost-effectiveness analyses of pulse oximetry screening (POS) for critical congenital heart defects (CCHDs) have shown it to be a cost-effective endeavour, but the geographical setting of Ontario in relation to its vast yet sparsely populated regions presents unique challenges. The objective of this study was to estimate the cost-effectiveness of POS for CCHD in Ontario, Canada.

METHODS

A cost-effectiveness analysis, comparing POS to no POS, was conducted from the Ontario healthcare payer perspective using a Markov model. The base case was defined as a well-appearing newborn at 24 h of age. Outcome measures, including quality-adjusted life months (QALMs), lifetime costs, and incremental cost-effectiveness ratios (ICER) [ΔCost/ΔQALMs], were calculated over a lifetime horizon. All outcomes were discounted at 1.5% per year. Cost-effectiveness was assessed using an a priori ICER threshold of CAD$4166.67 per QALM (equivalent to CAD$50,000 per quality-adjusted life year). Deterministic and probabilistic sensitivity analyses were conducted to assess parameter uncertainty.

RESULTS

Implementation of POS is expected to lead to timely diagnosis of 51 CCHD cases annually. The incremental cost of performing POS was estimated to be $27.27 per screened individual, with a gain of 0.02455 QALMs. This yielded an ICER of CAD$1110.79 per QALM, well below the pre-determined threshold. The probabilistic sensitivity analysis estimated a 92.3% chance of routine implementation of POS being cost-effective.

CONCLUSION

Routine implementation of POS for CCHD in Ontario is expected to be cost-effective.

Screening for congenital heart disease in a Singapore neonatal unit

INTRODUCTION

Congenital heart disease (CHD) is a leading cause of infant mortality. The aim of this study was to evaluate the efficacy of a neonatal screening programme for CHD before the introduction of pulse oximetry.

METHODS

This was a retrospective review of live births in the period 2003-2012. Cases of CHD were detected through prenatal ultrasonography and/or postnatal examination, and confirmed using two-dimensional echocardiography. Data was rigorously checked against multiple sources. The antenatal detection rate, sensitivity, specificity, predictive values and likelihood ratios of the screening programme were analysed for all cases of CHD and critical CHD.

RESULTS

The incidence of CHD was 9.7 per 1,000 live births. The commonest CHD was ventricular septal defect (54.8%). The antenatal detection rate was three times higher in the critical CHD group (64.0%) compared to the group as a whole (21.1%). The sensitivity and specificity of screening was 64.5% and 99.7% for all CHD, and 92.9% and 99.1% for the critical CHD group, respectively. The positive likelihood ratio was 215 and 103, while the negative likelihood ratio was 0.36 and 0.07 for all CHD and critical CHD, respectively.

CONCLUSION

The CHD screening programme had excellent specificity but limited sensitivity. The high positive likelihood ratios indicate that where sufficient risk factors for CHD are present, a positive result effectively confirms the presence of CHD. The low negative likelihood ratio for critical CHD indicates that, where prior suspicion for critical CHD is low, a negative result is reassuring.

Maternal and cord blood homocysteine, vitamin B12, folate, and B-type natriuretic peptide levels at term for predicting congenital heart disease of the neonate: A case-control study

Objective: To investigate the effectiveness of the metabolic markers homocysteine, vitamin B12, folate, and B-type natriuretic peptide in maternal and cord blood for detecting congenital heart disease.Methods: Homocysteine, vitamin B12, folate, and B-type natriuretic peptide concentrations in maternal and cord blood samples at term were measured in the case (n = 42) and control (n = 43) groups with and without fetal congenital heart disease, respectively. Additionally, newborns with congenital heart disease were divided into two subgroups: those with (n = 30) and without (n = 8) 6-month infant survival. The case and control groups and case subgroups were compared with each other with respect to maternal age, gravidity, parity, gestational age at delivery, birth weight, maternal and cord blood levels of homocysteine, vitamin B12, folate, and B-type natriuretic peptide, and arterial cord blood pH and base excess values. Statistical analyses were performed using SPSS for Windows, version 22.0. The Student's t-test, the Mann-Whitney U test, and the χ² test were used where appropriate. A p value of < .05 was considered statistically significant.Results: Mean maternal age, birth weight and median gravidity, parity and gestational age at delivery were not significantly different between the case and control groups, as well as between the case subgroups (all p > .05). Concentrations of metabolic markers in maternal blood were not significantly different between the two groups (p > .05). Homocysteine and B-type natriuretic peptide levels in cord blood samples were significantly higher, whereas folate levels were significantly lower in the case group compared with the control group (all p < .05). Cord blood B-type natriuretic peptide levels were significantly higher (p < .05) and arterial cord blood pH values were significantly lower (p < .05) in the case subgroup without 6-month infant survival compared with the case subgroup with 6-month infant survival.Conclusion: High cord blood B-type natriuretic peptide and homocysteine levels and low cord blood folate levels at term may be useful for predicting congenital heart disease in the neonate. Neonates with congenital heart disease who have high cord blood B-type natriuretic peptide and low pH values may have adverse outcomes.

Prenatal diagnosis of a bundle branch block based on the fetal ECG

A non-invasive fetal ECG was performed on a 36-year-old pregnant woman at 24+6 weeks of gestation as part of ongoing clinical research. A paediatric cardiologist suspected an incomplete bundle branch block based on the averaged ECGs from the recording. The characteristic terminal R' wave was present in multiple leads of the fetal ECGs. A fetal anomaly scan had been performed at 20 weeks of gestation and showed no abnormalities. An incomplete right bundle branch block was confirmed on an ECG recorded at the age of 2 years. This case shows the possibility of novel non-invasive fetal ECG technology as an adjunct to the diagnosis of fetal cardiac anomalies in the future.

Congenital Heart Disease in East Africa

Congenital Heart Disease (CHD) is an enormous problem in Low Middle Income Countries and particularly in sub-Saharan Africa. There is an estimated 500,000 children born in Africa with CHD each year with a major proportion of this in sub-Saharan Africa. The vast majority of these children receive sub-optimal or no care at all. In East Africa: Kenya, Tanzania, and Uganda have all attempted to create a CHD service for the last 20 years with minimal success due to various factors. Visiting cardiac missions have made considerable contributions in the development of CHD services in these countries, however there remains a significant number of children with lack of care. We explore the positive aspects of the current projects, the various factors that hinder growth in this area, and what can be done to promote CHD service growth in these countries.

Parents' experiences of receiving an antenatal versus postnatal diagnosis of complex congenital heart disease

BACKGROUND

The time point at which parents receive a diagnosis of congenital heart disease (CHD) has changed over the years due in part to advances in fetal ultrasound. However, CHD remains undiscovered until after birth in some cases. The psychological effect of time of diagnosis on parents' experiences has not been well researched.

AIM

To explore parents' experiences at the time of diagnosis of complex CHD and to compare if experiences differ when receiving an antenatal versus postnatal diagnosis.

METHOD

Descriptive and thematic analysis of primary mixed qualitative and quantitative data, collected in 2012-2013, from an online survey of parents ( n =22) whose infants had undergone stage one surgery for a functionally univentricular heart.

FINDINGS

Four themes emerged: parents' understanding of the condition at the time of diagnosis; parents' emotions at the time of diagnosis; sources of support at the time of diagnosis; and additional sources of information after the diagnosis.

CONCLUSION

There are implications for practice in terms of who provides the diagnosis and, more importantly, how well it is explained. Professionals need to assess parents' emotional status, information needs and level of understanding irrespective of time of diagnosis, so that support is individualised, sensitive and time appropriate.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Prenatal diagnosis of congenital heart disease

This review article will guide the reader through the background of prenatal screening for congenital heart disease. The reader will be given insight into the normal screening views, common abnormalities, risk stratification of lesions and also recent advances in prenatal cardiology.

Use of prostaglandins in duct-dependent congenital heart conditions

Congenital heart disease (CHD) remains a leading cause of infant mortality, which is even higher in infants with undiagnosed duct-dependent CHDs. Up to 39%-50% of infants with critical CHD are being discharged undiagnosed from the hospital. Infants with duct-dependent critical CHD remain well during the fetal period and may deteriorate when the ductus arteriosus (commonly called 'duct') closes after birth. It is critical to open or maintain ductus arteriosus patent in infants with duct-dependent CHDs. Prostaglandin E1 (alprostadil marketed as 'Prostin VR ') and prostaglandin E2 (dinoprostone) are used to maintain a patent ductus arteriosus and the dose of medication depends on the clinical presentation. Delay in starting prostaglandin infusion can have deleterious effects on infants and can even lead to death. These infants often present as an emergency, and professionals caring for these infants need to have a good understanding of these conditions and medications used for ductal patency.

Single centre audit of early impact of inclusion of the three vessel and trachea view in obstetric screening

Detection rates of congenital cardiac malformations have traditionally remained low. The NHS Fetal Anomaly Screening Programme (FASP) aims to increase these detection rates for various reasons, including influencing perinatal management and aiding parental decision making. The inclusion of the three vessel view and trachea (3VT) view in 2015 aimed to improve detection rates of arch abnormalities in particular. This study evaluated the early impact of the new initiative at one NHS Trust. Departmental screen-positive rates were compared for a full year before and after implementation. Referrals to, and opinions of, the foetal medicine unit (FMU) were assessed; as were undetected congenital heart defects for the two time periods. Compared with the pre-implementation (pre-3VT) period, the number of completed anomaly scans performed after implementation (post-3VT) increased by 3% and the number of FMU referrals increased by 625%. Departmental screen-positive rates for cardiac abnormalities increased from 40% (pre-3VT) to 91% (post-3VT). Over half (52%) of the FMU referrals were made due to a suspected abnormal 3VT view. Early evaluation of 3VT implementation at this NHS Trust indicates that it has been a success. Departmental screen-positive rates for congenital cardiac malformations have risen. However, this performance has come at a cost: Some abnormalities now being detected, such as loose vascular ring and PLSVC, are frequently asymptomatic and likely to be clinically insignificant. The implementation of 3VT achieves the aims of FASP but may begin to exceed what is expected from a low risk population screening programme.

Systematic review and meta-analysis of the performance of second-trimester screening for prenatal detection of congenital heart defects

BACKGROUND

The prenatal detection rate of congenital heart defects (CHDs) is increasing, but reported rates vary.

OBJECTIVES

To determine the performance of the second-trimester anomaly scan to detect CHD.

SEARCH STRATEGY

PubMed and Embase were searched for relevant studies in any language from inception to February 3, 2017. The search terms included "prenatal diagnosis" or "pregnancy," "cardiovascular diseases" or "cardiac defects," "congenital," and "specificity," or "sensitivity," or "cohort study."

SELECTION CRITERIA

Cohort studies assessing the detection rate of CHD during population-based prenatal screening from 1995 were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Data were collected from identified studies; authors were approached for additional data when necessary. A review and meta-analysis were performed. When possible, separate analyses were undertaken for isolated CHD cases.

MAIN RESULTS

Meta-analysis of seven studies showed the pooled detection rate of CHD in unselected populations as 45.1% (95% confidence interval 33.5%-57.0%). However, the rate of detection of univentricular defects and heterotaxy was above 85%. Similar rates were found among cases of isolated CHD.

CONCLUSIONS

Prenatal detection showed a strong correlation with CHD severity. The detection of conotruncal anomalies needs to improve. A thoroughly organized screening program will be essential to achieve a higher detection rate.

Changes in the diagnosis of congenital cardiovascular malformations during the 1st year of life: impacts on epidemiological risk factor associations

Many epidemiological studies base their classification of congenital cardiovascular malformations in newborns upon a single, initial diagnosis. This study aimed to evaluate the effect of subsequent diagnostic investigations on the results of epidemiological studies. We used diagnostic codes from the Baltimore-Washington Infant Study from the time of birth and at ~1 year of age. Odds ratios and 95% confidence intervals were used to identify associations between changes in diagnoses and infant characteristics, time period, that is, before and after introduction of color flow Doppler imaging, and diagnostic variables. Of the 3054 patients with data at both time points, 400 (13.1%) had diagnostic changes. For congenital cardiovascular malformations of early cardiogenesis, such as laterality and looping defects, conotruncal malformations, and atrioventricular septal defects, significant associations were observed between diagnostic change and case infants large for gestational age (odds ratio=0.22, p=0.01), diagnosed initially by echocardiography only (odds ratio=2.05, p=0.001), or with non-cardiac malformations (odds ratio=0.60, p=0.03). For all other congenital cardiovascular malformations, significant associations were observed with echocardiography-only diagnosis (odds ratio=1.43, p=0.04) and non-cardiac malformations (odds ratio=0.57, p<0.001). We found no statistically significant differences between risk factor odds ratios calculated using initial diagnoses versus those calculated using 1-year update diagnoses. Changes in congenital cardiovascular malformation diagnoses from birth to year 1 interval were significantly associated with infant characteristics and diagnostic modality but did not materially affect the outcome of risk factor associations.

Three- and four-dimensional ultrasound in fetal echocardiography: an up-to-date overview

Congenital heart diseases (CHD) are the most commonly overlooked lesions in prenatal screening programs. Real-time two-dimensional ultrasound (2DUS) is the conventionally used tool for fetal echocardiography. Although continuous improvements in the hardware and post-processing software have resulted in a good image quality even in late first trimester, 2DUS still has its limitations. Four-dimensional ultrasound with spatiotemporal image correlation (STIC) is an automated volume acquisition, recording a single three-dimensional (3D) volume throughout a complete cardiac cycle, which results in a four-dimensional (4D) volume. STIC has the potential to increase the detection rate of CHD. The aim of this study is to provide a practical overview of the possibilities and (dis)advantages of STIC. A review of literature and evaluation of the current status and clinical value of 3D/4D ultrasound in prenatal screening and diagnosis of congenital heart disease are presented.

Prenatal diagnosis of congenital heart defects: accuracy and discrepancies in a multicenter cohort

OBJECTIVE

To examine the accuracy of fetal echocardiography in diagnosing congenital heart disease (CHD) at the fetal medicine units of three tertiary care centers.

METHODS

This was a multicenter cohort study of tertiary echocardiography referrals between 2002 and 2012. Prenatal and postnatal diagnoses were compared and the degree of agreement was classified as 'correct' (anatomy correct and the postnatal diagnosis led to a similar outcome as expected), 'discrepant' (anatomical discrepancies present but the severity and prognosis of the defect were diagnosed correctly) or 'no similarity' (the pre- and postnatal diagnoses differed completely).

RESULTS

We included 708 cases with CHD for which both prenatal and postnatal data were available. The prenatal diagnosis was correct in 82.1% of cases and discrepancies present were present in 9.9%; however, these did not result in a different outcome. In 8.1% there was no similarity between prenatal and postnatal diagnoses. Disagreement between pre- and postnatal diagnoses occurred significantly more frequently in cases that presented with a normal four-chamber view than in those with an abnormal four-chamber view (5.5% vs 1.9%). Incorrect identification of the outflow tracts and incorrect differentiation between unbalanced atrioventricular septal defect and hypoplastic left heart syndrome were relatively commonly encountered. In many cases with disagreement, trisomy 21, extracardiac anomaly or a high maternal body mass index was present.

CONCLUSIONS

The prenatal diagnosis and estimated prognosis of fetal echocardiography in our tertiary referral centers were appropriate in 92% of cases. Some types of CHD remain difficult to diagnose or rule-out prenatally, therefore awareness and education are of considerable importance. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

The Application of an Anatomical Database for Fetal Congenital Heart Disease

Background:

Fetal congenital heart anomalies are the most common congenital anomalies in live births. Fetal echocardiography (FECG) is the only prenatal diagnostic approach used to detect fetal congenital heart disease (CHD). FECG is not widely used, and the antenatal diagnosis rate of CHD varies considerably. Thus, mastering the anatomical characteristics of different kinds of CHD is critical for ultrasound physicians to improve FECG technology. The aim of this study is to investigate the applications of a fetal CHD anatomic database in FECG teaching and training program.

Methods:

We evaluated 60 transverse section databases including 27 types of fetal CHD built in the Prenatal Diagnosis Center in Peking University People's Hospital. Each original database contained 400–700 cross-sectional digital images with a resolution of 3744 pixels × 5616 pixels. We imported the database into Amira 5.3.1 (Australia Visage Imaging Company, Australia) three-dimensional (3D) software. The database functions use a series of 3D software visual operations. The features of the fetal CHD anatomical database were analyzed to determine its applications in FECG continuing education and training.

Results:

The database was rebuilt using the 3D software. The original and rebuilt databases can be displayed dynamically, continuously, and synchronically and can be rotated at arbitrary angles. The sections from the dynamic displays and rotating angles are consistent with the sections in FECG. The database successfully reproduced the anatomic structures and spatial relationship features of different fetal CHDs. We established a fetal CHD anatomy training database and a standardized training database for FECG. Ultrasound physicians and students can learn the anatomical features of fetal CHD and FECG through either centralized training or distance education.

Conclusions:

The database of fetal CHD successfully reproduced the anatomic structures and spatial relationship of different kinds of fetal CHD. This database can be widely used in anatomy and FECG teaching and training.

Identification of copy number variations associated with congenital heart disease by chromosomal microarray analysis and next-generation sequencing

OBJECTIVE

To determine the type and frequency of pathogenic chromosomal abnormalities in fetuses diagnosed with congenital heart disease (CHD) using chromosomal microarray analysis (CMA) and validate next-generation sequencing as an alternative diagnostic method.

METHOD

Chromosomal aneuploidies and submicroscopic copy number variations (CNVs) were identified in amniocytes DNA samples from CHD fetuses using high-resolution CMA and copy number variation sequencing (CNV-Seq).

RESULT

Overall, 21 of 115 CHD fetuses (18.3%) referred for CMA had a pathogenic chromosomal anomaly. In six of 73 fetuses (8.2%) with an isolated CHD, CMA identified two cases of DiGeorge syndrome, and one case each of 1q21.1 microdeletion, 16p11.2 microdeletion and Angelman/Prader Willi syndromes, and 22q11.21 microduplication syndrome. In 12 of 42 fetuses (28.6%) with CHD and additional structural abnormalities, CMA identified eight whole or partial trisomies (19.0%), five CNVs (11.9%) associated with DiGeorge, Wolf-Hirschhorn, Miller-Dieker, Cri du Chat and Blepharophimosis, Ptosis, and Epicanthus Inversus syndromes and four other rare pathogenic CNVs (9.5%). Overall, there was a 100% diagnostic concordance between CMA and CNV-Seq for detecting all 21 pathogenic chromosomal abnormalities associated with CHD.

CONCLUSION

CMA and CNV-Seq are reliable and accurate prenatal techniques for identifying pathogenic fetal chromosomal abnormalities associated with cardiac defects. © 2016 John Wiley & Sons, Ltd.

Epigenetic markers for newborn congenital heart defect (CHD)

OBJECTIVE

Our objective was to determine whether there were significant differences in genome-wide DNA methylation in newborns with major congenital heart defect (CHD) compared to controls. We also evaluated methylation of cytosines in CpG motifs for the detection of these CHDs.

METHODS

Genome-wide DNA methylation analysis was performed on DNA from 60 newborns with various CHDs, including hypoplastic left heart syndrome, ventricular septal deficit, atrial septal defect, pulmonary stenosis, coarctation of the aorta and Tetralogy of Fallot, and 32 controls.

RESULTS

Highly significant differences in cytosine methylation were seen in a large number of genes throughout the genome for all CHD categories. Gene ontology analysis of CHD overall indicated over-represented biological processes involving cell development and differentiation, and anatomical structure morphogenesis. Methylation of individual cytosines in CpG motifs had high diagnostic accuracy for the detection of CHD. For example, for coarctation one predictive model based on levels of particular cytosine nucleotides achieved a sensitivity of 100% and specificity of 93.8% (AUC = 0.974, p < 0.00001).

CONCLUSION

Profound differences in cytosine methylation were observed in hundreds of genes in newborns with different types of CHD. There appears to be the potential for development of accurate genetic biomarkers for CHD detection in newborns.

Prenatal detection of congenital heart disease--results of a national screening programme

OBJECTIVE

Congenital heart disease (CHD) is the most common congenital malformation and causes major morbidity and mortality. Prenatal detection improves the neonatal condition before surgery, resulting in less morbidity and mortality. In the Netherlands a national prenatal screening programme was introduced in 2007. This study evaluates the effects of this screening programme.

DESIGN

Geographical cohort study.

SETTING

Large referral region of three tertiary care centres.

POPULATION

Fetuses and infants diagnosed with severe CHD born between 1 January 2002 and 1 January 2012.

METHODS

Cases were divided into two groups: before and after the introduction of screening.

MAIN OUTCOME MEASURES

Detection rates were calculated.

RESULTS

The prenatal detection rate (n = 1912) increased with 23.9% (95% confidence interval [95% CI] 19.5-28.3) from 35.8 to 59.7% after the introduction of screening and of isolated CHD with 21.4% (95% CI 16.0-26.8) from 22.8 to 44.2%. The highest detection rates were found in the hypoplastic left heart syndrome, other univentricular defects and complex defects with atrial isomerism (>93%). Since the introduction of screening, the 'late' referrals (after 24 weeks of gestation) decreased by 24.3% (95% CI 19.3-29.3).

CONCLUSIONS

This is the largest cohort study to investigate the prenatal detection rate of severe CHD in an unselected population. A nationally organised screening has resulted in a remarkably high detection rate of CHD (59.7%) compared with earlier literature.

4D Fetal Echocardiography in Clinical Practice

Spatiotemporal image correlation (STIC) is a technique that acquires the fetal cardiac volumes, and then analyzes it offline in both multiplanar and rendered modes, using both static and moving images from a four-dimensional (4D) cine sequence simulating a full cardiac cycle. Spatiotemporal image correlation makes it possible to evaluate cardiac structures and their vascular connections, is less operator dependent, and allows cardiac volumes to be sent to specialists in tertiary centers for examination. Spatiotemporal image correlation can be combined with other software techniques, such as virtual organ computer-aided analysis (VOCAL) and automatic volume calculation (SonoAVC), to calculate cardiac function parameters. It can also be used in association with Omniview® in order to obtain standard echocardiographic planes using simple targets arterial rendering (STAR) and four-chamber view and swing technique (FAST). Recently, fetal intelligent navigation echocardiography (FINE), acquired from 3D STIC volumes, has made it possible to automatically obtain nine standard echocardiographic planes. In this article, we review the chief applications of 4D echocardiography using STIC technique in clinical practice.

How to cite this article

Araujo Júnior E, Tedesco GD, Carrilho MC, Peixoto AB, Carvalho FHC. 4D Fetal Echocardiography in Clinical Practice. Donald School J Ultrasound Obstet Gynecol 2015;9(4): 382-396.

Metabolomic prediction of fetal congenital heart defect in the first trimester

OBJECTIVE

The objective of the study was to identify metabolomic markers in maternal first-trimester serum for the detection of fetal congenital heart defects (CHDs).

STUDY DESIGN

Mass spectrometry (direct injection/liquid chromatography and tandem mass spectrometry) and nuclear magnetic resonance spectrometry-based metabolomic analyses were performed between 11 weeks' and 13 weeks 6 days' gestation on maternal serum. A total of 27 CHD cases and 59 controls were compared. There were no known or suspected chromosomal or syndromic abnormalities indicated.

RESULTS

A total of 174 metabolites were identified and quantified using the 2 analytical methods. There were 14 overlapping metabolites between platforms. We identified 123 metabolites that demonstrated significant differences on a univariate analysis in maternal first-trimester serum in CHD vs normal cases. There was a significant disturbance in acylcarnitine, sphingomyelin, and other metabolite levels in CHD pregnancies. Predictive algorithms were developed for CHD detection. High sensitivity (0.929; 95% confidence interval [CI], 0.92-1.00) and specificity (0.932; 95% CI, 0.78-1.00) for CHD detection were achieved (area under the curve, 0.992; 95% CI, 0.973-1.0).

CONCLUSION

In the first such report, we demonstrated the feasibility of the use of metabolomic developing biomarkers for the first-trimester prediction of CHD. Abnormal lipid metabolism appeared to be a significant feature of CHD pregnancies.

Anesthetic considerations for neonates undergoing modified Blalock-Taussig shunt and variations

The first Blalock-Taussig (BT) shunt was reported in 1944, and during the last 70 years, the procedure has evolved with the development of new materials and devices, and surgical approaches. It has, however, remained central to the palliation of neonates with complex congenital heart disease. The indications have expanded from the original aim of alleviating cyanosis and the pathophysiological results of chronic hypoxemia. They now include lesions with single ventricles, and rehabilitation of small pulmonary arteries. The physiology and hemodynamics of BT shunt circulations are very complex, and adverse hemodynamic events can be difficult to recognize. The consequences of shunt failure can be fatal, and the mortality (3-15%) and morbidity remain distressingly high even in the current era. Neonates undergoing BT shunt procedures or undergoing noncardiac surgery with this anatomy are challenging for the anesthesiologists to manage. There is a significant incidence of periprocedural cardiac arrest, often related to myocardial ischemia. A clear understanding of the anatomy and physiology is important. Any discussion of BT shunt in the current era has to include consideration of hypoplastic left heart syndrome and 'single ventricle' physiology.

A Simple Effective Protocol to Increase Prenatal Detection of Critical Congenital Heart Disease

Prenatal diagnosis of congenital heart disease (CHD) during routine obstetric sonography has been aptly named the sonographer’s Achilles heel. Although CHD occurs more commonly than any other major congenital abnormality, the detection rate remains low. The goal of this study was to improve the prenatal diagnosis of CHD during routine obstetric sonography through the development and implementation of a simple and effective screening protocol.

A potential relationship among beta-defensins haplotype, SOX7 duplication and cardiac defects

OBJECTIVE

To determine the pathogenesis of a patient born with congenital heart defects, who had appeared normal in prenatal screening.

METHODS

In routine prenatal screening, G-banding was performed to analyse the karyotypes of the family and fluorescence in situ hybridization was used to investigate the 22q11.2 deletion in the fetus. After birth, the child was found to be suffering from heart defects by transthoracic echocardiography. In the following study, sequencing was used to search for potential mutations in pivotal genes. SNP-array was employed for fine mapping of the aberrant region and quantitative real-time PCR was used to confirm the results. Furthermore, other patients with a similar phenotype were screened for the same genetic variations. To compare with a control, these variations were also assessed in the general population.

RESULTS

The child and his mother each had a region that was deleted in the beta-defensin repeats, which are usually duplicated in the general population. Besides, the child carried a SOX7-gene duplication. While this duplication was not detected in his mother, it was found in two other patients with cardiac defects who also had the similar deletion in the beta-defensin repeats.

CONCLUSION

The congenital heart defects of the child were probably caused by a SOX7-gene duplication, which may be a consequence of the partial haplotype of beta-defensin regions at 8p23.1. To our knowledge, this is the first congenital heart defect case found to have the haplotype of beta-defensin and the duplication of SOX7.

Early fetal anatomical sonography

Over the past decade, prenatal screening and diagnosis has moved from the second into the first trimester, with aneuploidy screening becoming both feasible and effective. With vast improvements in ultrasound technology, sonologists can now image the fetus in greater detail at all gestational ages. In the hands of experienced sonographers, anatomic surveys between 11 and 14 weeks can be carried out with good visualisation rates of many structures. It is important to be familiar with the normal development of the embryo and fetus, and to be aware of the major anatomical landmarks whose absence or presence may be deemed normal or abnormal depending on the gestational age. Some structural abnormalities will nearly always be detected, some will never be and some are potentially detectable depending on a number of factors.