Detection rate of early fetal echocardiography and in utero development of congenital heart defects

Fetal Echocardiography From 10 to 15 Weeks of Gestation-Reliability, Genetic Associations, and Outcomes

INTRODUCTION

There is increasing demand for accurate early fetal cardiac disease (FCD). We assessed the accuracy of early fetal echo (EFE) conducted in our high-volume fetal cardiac program and reviewed the spectrum of FCD, associated genetic anomalies, and outcomes encountered.

METHODS

We identified all EFEs performed from 10+0 to 15+6 weeks of gestation from 2009 to 2021. We compared findings at EFE to fetal echo at ≥18+0 weeks or autopsy and documented genetic testing results for all FCD cases. For those with discrepancy between EFE and later exam, the discrepancy impact was reviewed. A score was used to quantify the anatomy assessed.

RESULTS

A total of 1,662 EFEs were performed in 1,387 pregnancies; all but 41 were considered diagnostic. Fetal cardiac disease was diagnosed at EFE in 130, including 101 major, 12 minor, 13 other FCD, and 4 arrhythmias. In 14/130 with FCD, endovaginal imaging was undertaken, which increased the score (1.6/9 vs 3.5/9; P = .049). Thirty-five of 130 had repeat EFE, which increased the score (5.2/9 vs 7.4/9, P < .0001). Fetal loss occurred before confirmation of FCD in 16 and termination in 64, and 11 were lost to follow-up. Thirty-nine had autopsy and/or fetal echo ≥18+0: 35 had FCD confirmed, and 4 had resolution. Of the 35 confirmed FCD, 27 had no, 7 minor, and 1 major change. Of 1,489 with normal EFE, later echo demonstrated FCD in 14: 3 major and 11 minor. In 16, FCD evolved, including 4 arrhythmias and 12 with progressive FCD. Sensitivity, specificity, and positive and negative predictive values of EFE in identifying major FCD were 92.9%, 100%, 100%, and 99.7%, respectively. In cases with FCD, 85.4% had genetic testing, of whom 71% (60.8% of the total) had abnormal results.

CONCLUSIONS

In our experience, EFE permits accurate diagnosis and exclusion of most FCD. Endovaginal imaging and repeat EFE studies improved the ability to visualize structures adequately.

Referral pattern of pregnant mother for fetal echocardiography in Shiraz, South Iran

OBJECTIVE

To evaluate the referral patterns for fetal echocardiography at a tertiary care center in Shiraz, South Iran.

METHOD

This retrospective cohort study analyzed data from 22,600 pregnant women who underwent fetal echocardiography between January 1, 2016, and December 31, 2021. Information was extracted from a centralized electronic medical record system used by medical centers affiliated with Shiraz University of Medical Sciences.

RESULT

Congenital heart disease was detected in 14.5% of fetal echocardiograms. The mean gestational age at the time of examination was 21.8 ± 4.2 weeks (range: 13-40 weeks). Notably, 75.9% of pregnant women were referred after 19 weeks of gestation. The most common reason for referral was abnormal fetal laboratory screening (triple or quad test).

CONCLUSION

In our center, fetal echocardiography is optimally performed by 19 weeks of gestation. This timing allows for detailed anatomical assessment and aligns with the legal threshold for abortion, ensuring timely counseling and decision-making when necessary. However, in our study, the mean gestational age at the time of echocardiography was 21 weeks, indicating that a significant proportion of patients underwent the procedure later than the optimal timing.

Managing CHD in Tertiary NICU in Collaboration with a Cardiothoracic Center

Increasingly non-cardiac tertiary neonatal intensive care units (NCTNs) manage newborns with CHD prior to planned transfer to specialist cardiac surgical centres (SCSC). It improves patient flow in SCSCs, enables families to be nearer home, and improves psychological well-being Parker et al. (Evaluating models of care closer to home for children and young people who are ill: a systematic review, 2011). This practice has gradually increased as the number of SCSCs has decreased. This study examines the effectiveness of this expanding practice. The management provided, length of stay in the NCTN and outcomes are described for one UK NCTN situated at a significant distance from its SCSC. A retrospective observational study of cardiac-related admissions to a NCTN between January 2010 and December 2019 was conducted. 190 neonates were identified: 41 had critical CHD; 64 had major CHD. The cohort includes babies with a wide range of cardiac conditions and additional complexities. 23.7% (n = 45) required transfer to a specialist center after a period of stabilization and growth ranging from several hours to 132 days. 68% (n = 130) were discharged home or repatriated to a local NICU. Of the remaining 15 babies, 13 were transferred to other specialties including the hospice. Two died on NICU. The mortality was consistent with the medical complexity of the group Best and Rankin (J Am Heart Assoc 5:e002846, 2016), Laas et al. (BMC Pediatr 17:124, 2017). 8.9% (n = 17) died before age 2. Nine babies had care redirected due to an inoperable cardiac condition or life-limiting comorbidities. Our study demonstrates a complex neonatal cohort with CHD can be managed effectively in a NCTN, supporting the current model of care. The NCTN studied was well supported by pediatricians with expertise in cardiology alongside visiting pediatric cardiologists.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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.

Ultrasound Patterns in the First Trimester Diagnosis of Congenital Heart Disease

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

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.

Performance of First-Trimester Fetal Echocardiography in Diagnosing Fetal Heart Defects: Meta-analysis and Systematic Review

OBJECTIVES

Early fetal echocardiography is becoming increasing common during the nuchal translucency scan period. The aim of this meta-analysis was to assess the accuracy of first-trimester fetal echocardiography in diagnosing congenital heart defects (CHDs).

METHODS

The databases of PubMed, Embase, the Cochrane Library, and the Cumulative Index to Nursing and Allied Health Literature were systematically searched for the candidate articles, and the references of included studies were also examined. We recorded the characteristics of the included studies and assessed the quality of each study by the Quality Assessment of Diagnostic Accuracy Studies tool. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were calculated with Meta-Disc version 1.4 software (Ramón y Cajal Hospital, Madrid, Spain). We also evaluated the publication bias by using Stata version 12.0 software (StataCorp, College Station, TX).

RESULTS

This meta-analysis included 18 studies with 26,201 fetal hearts. The overall pooled sensitivity, specificity, PLR, and NLR were 0.750, 0.999, 392.95, and 0.277, respectively. The DOR and AUC were 1736.0 and 0.9331. The pooled sensitivity, specificity, PLR, NLR, DOR, and AUC for major CHDs were 0.838, 1.000, 725.69, 0.203, 5084.8, and 0.9617.

CONCLUSIONS

First-trimester fetal echocardiography had high value in diagnosing CHDs, especially major CHDs.

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.

Importance of Follow-Up and Early Detailed Evaluation in Early Onset Growth Restricted Fetuses

Early onset fetal growth restriction (EO-FGR) is associated with significant feto-maternal complications, therefore efforts should be made to identify the causes and the potential outcome of the pregnancy. Some of the pitfalls in first-trimester imaging of the fetal anomalies are related to the inadequacy of the examination, because of the fetal position and limited clarity in relation to the size of the structures being examined. In this paper we present a case where careful ultrasound scan follow-up and the use of both approaches transabdominal and transvaginal were useful to complete a detailed structural evaluation as part of the diagnosis, management and prognosis of a fetuses diagnosed with EO-FGR in the first trimester and a triploidy with atypical ultrasound features.

Radiologist's Guide to Diagnosis of Fetal Cardiac Anomalies on Prenatal Ultrasound Imaging

Congenital cardiac anomalies are a common finding during prenatal anatomical survey ultrasound examination. Cardiac anomalies are a major cause of prenatal and neonatal mortality and morbidity. If the anomaly is not lethal, most would require surgical correction. Therefore, early recognition of these abnormalities is essential for parental counseling and delivery planning, as well as analysis of neonatal treatment options. Although prenatal ultrasound plays an important role in identification of such anomalies, diagnosis and interpretation of imaging findings require familiarity and knowledge of the common imaging features. In this article, we provide a comprehensive review of ultrasound appearance of common fetal cardiac anomalies.

The outcome of structural heart defects diagnosed in the first trimester of pregnancy

PURPOSE

We present the results of a detailed protocol of fetal heart examination in the first trimester, in a fetal medicine unit in Romania.

METHODS

Since October 2009, in Filantropia Hospital in Bucharest, we have systematically assessed pregnancies at 11-14 weeks to screen for aneuploidies and for major fetal structural defects. The fetal anatomy examination protocol included the detailed assessment of the fetal heart. This was performed using the same principles as for the second trimester examination, in the entire cohort.

RESULTS

Our population consisted of 7693 patients and 7816 embryos. The protocol for the ultrasound evaluation of the fetal heart was completed for 7597 embryos (97.2%). The outcome is known for 6912 cases (90.9%). We diagnosed 39 heart defects - 30 in the first trimester, seven in the second trimester, two postnatally. Twenty of the 39 heart defects were isolated cardiac malformations. Twelve of the isolated heart defects were diagnosed in the first trimester. The sensitivity of the first trimester ultrasound in identifying major heart defects was 76.92%. The overall survival in cases of isolated congenital heart disease diagnosed in the first trimester was significantly lower than the survival in the cases diagnosed in the second trimester.

CONCLUSIONS

Many (76.92%) of the significant heart defects can be diagnosed by ultrasound examination, in the first trimester. Our study is an argument for developing the multidisciplinary approach needed for the management of early detected structural heart disease.

Screening for congenital heart defects: diversified strategies in current China

Background

Congenital heart defects (CHD) is the most common type of birth defect and a leading cause of infant mortality in China. Detection of CHD during newborn is still challenging. The contradiction between the increasingly mature technology of diagnosis and treatment and the inability of early detection is the biggest current dilemma. A few pilot studies attempt to establish the universal screening for CHD in newborns; however, the rate of misdiagnosis is still high in most Chinese hospitals, especially in some undeveloped middle-western regions.

Data sources

Based on the recent publications on screening of congenital heart diseases in China. We reviewed the use of diversified screening strategies in current China.

Results

Prenatal diagnosis by fetal echocardiography and postnatal detection by pulse oximetry combined with clinical assessment are the useful methods for CHD screening in most areas. The altitude should be taken into account when using pulse oximetry in the middle-western areas of China, where the incidence of CHD maybe higher. Echocardiography is suitable for CHD screening in almost all areas but it could add to financial burden in the developing regions. Genetic analysis could assist clinical doctors to perform more earlier screening and give better counseling regarding the outcome. Due to disparities in economic and medical resources, the screening system should be carried out from multiple perspectives according to the present economic development. Notably, follow-up is an important issue in the screening of CHD, especially for the asymptomatic babies who discharged home. Policies should be formulated to address the epidemiology of CHD in deprived areas to better allocate medical resources and to develop local training programmes to screen and diagnose CHD.

Conclusions

Diversified strategies are available in current China. The two-indicator method for CHD screening is recommended to be implemented in routine postnatal care. We can do more in screening for CHD in the future.

Role of HDLive in Imaging the Fetal Heart

HDLive is a rendering methodology that generates realistic images of the human fetus from sonographic data. The objective of this study is to demonstrate the utility of high-definition live in evaluating fetal heart especially in the first trimester (11-14-week) scan. The normal atrioventricular valve and its abnormalities along with septal defects can be vividly demonstrated with this technique, and eight cases with cardiac defects are illustrated. Its use in the first-trimester evaluation of heart would give a better perspective of the cardiac malformation, which provides the opportunity for counseling options early in pregnancy.

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.

Prenatal detection of congenital heart defects at the 11- to 13-week scan using a simple color Doppler protocol including the 4-chamber and 3-vessel and trachea views

OBJECTIVES

The first goal of this study was to analyze the diagnostic performance of the 4-chamber view, 3-vessel and trachea view, and their combination in color mapping during early cardiac evaluations for selecting cases suspicious of congenital heart defects. The second goal was to describe the most common abnormal flow patterns at the levels of the 4-chamber and 3-vessel and trachea views in the late first trimester.

METHODS

We conducted a prospective observational study in which a simple cardiac sonographic protocol was applied in fetuses at gestational ages of 11 weeks to 13 weeks 6 days.

RESULTS

A total of 1084 patients with known postnatal or autopsy findings were included in the study. The median maternal age was 32.3 years (range, 27-40 years). The median crown-rump length was 62.2 mm (range, 45-84 mm). Overall, there were 35 cases with a confirmed congenital heart defect (3.22%), including 16 accompanied by aneuploidy. We found that our simple first-trimester cardiac protocol was an effective screening method for congenital heart defects. The most effective approach of the 3 evaluated by us was the combined application of the 4-chamber and 3-vessel and trachea views in color mapping compared to the 4-chamber and 3-vessel and trachea views alone. We defined the most common ventricular inflow patterns and the V sign. The technique we used was simple and easy to reproduce.

CONCLUSIONS

We confirmed that evaluation by two basic cardiac views allows for selection of most cases with a univentricular heart, atrioventricular septal defects, coarctation of the aorta, pulmonary stenosis, pulmonary atresia, and conotruncal defects.

Acoustic output measured by thermal and mechanical indices during fetal echocardiography at the time of the first trimester scan

We measured acoustic output, expressed as the thermal index (TI) and mechanical index (MI), during fetal echocardiography at the time of the first trimester scan. TI and MI were retrieved from the saved displays during gray-mode, high-definition color flow Doppler and pulsed-wave Doppler (tricuspid flow) ultrasound examinations of the fetal heart and from the ductus venosus assessment. A total of 399 fetal cardiac examinations were evaluated. There was a significant increase in TI values from B-mode studies (0.07 ± 0.04 [mean ± SD]) to color flow mapping (0.2 ± 0.0) and pulsed-wave Doppler studies (0.36 ± 0.05). The TI from ductus venosus assessment (0.1 ± 0.01) was significantly lower than those from Doppler examinations of the heart. MI values from B-mode scans (0.65 ± 0.12) and color flow mapping (0.71 ± 0.11) were comparable, although different, and both values were higher than those from pulsed-wave Doppler tricuspid evaluation (0.39 ± 0.03). There were no differences in MI values from power Doppler assessment between the tricuspid flow and ductus venosus. Safety indices were remarkably stable and were largely constant, especially for color Doppler (TI), tricuspid flow (MI) and ductus venosus assessment (TI, MI). We acquired satisfactory Doppler images and/or signals at acoustic levels that were lower than the actual recommendations and never reached a TI of 0.5.

First-trimester fetal cardiac examination using spatiotemporal image correlation, tomographic ultrasound and color Doppler imaging for the diagnosis of complex congenital heart disease in high-risk patients

OBJECTIVE

A four-dimensional (4D) fetal echocardiographic technique utilizing spatiotemporal image correlation, tomographic ultrasound imaging display (STIC-TUI echo) and color Doppler has previously been shown to be effective in displaying the examination planes constituting the extended cardiac examination. The aim of this study was to evaluate the performance of this first-trimester STIC-TUI echo technique in identifying complex congenital heart disease (CHD) in high-risk pregnancies.

METHODS

This was a prospective study of patients presenting at first-trimester screening who were at high risk for CHD owing to pregestational diabetes, in-vitro fertilization (IVF), increased nuchal translucency (NT) thickness, first-trimester tricuspid regurgitation or reversed ductus venosus (DV) a-wave, a previous child with CHD or who were on anticonvulsant medication. First-trimester STIC-TUI echo was performed, and the findings were correlated with second-trimester echocardiography and post-delivery echo findings in survivors.

RESULTS

One hundred and sixty-four fetuses from 152 patients were enrolled (77 diabetics, 38 IVF, 14 with increased NT, 23 cases of tricuspid regurgitation or reversed a-wave in the DV, 22 with prior CHD and two on anticonvulsants). STIC-TUI echo was abnormal in 20 (12%), showing atrioventricular canal defect (n = 9), hypoplastic left heart (n = 2), pulmonary stenosis (n = 2), right aortic arch (n = 1), interrupted aortic arch (n = 1), tricuspid atresia (n = 1), heterotaxy (n = 1), persistent truncus arteriosus (n = 1), double outlet right ventricle and ventricular septal defect (n = 1) and double inlet ventricle with transposition of the great arteries (n = 1). 85% of these anomalies were evident in the four-chamber view plane of the TUI display, and the remainder were diagnosed in the outflow tract planes with color Doppler imaging. In 13, CHD was isolated while seven had extracardiac anomalies. Thirteen fetuses had aneuploidy and all 13 underwent first-trimester termination of pregnancy. In the remaining seven, second-trimester echocardiography and neonatal echo/postmortem examination confirmed anomalies (two stillborn neonates, one neonatal death, four live births). Two cases of CHD missed by first-trimester STIC-TUI echo were diagnosed on second-trimester echo. Accordingly, first-trimester STIC-TUI echo had 91% sensitivity and 100% specificity for the detection of CHD.

CONCLUSIONS

First-trimester 4D echocardiography using a standardized application of STIC, TUI and color Doppler imaging is effective in displaying the imaging planes that are necessary for achieving the diagnosis of complex cardiac anomalies in high-risk patients. Optimal imaging of the four-chamber view with two-dimensional ultrasound is the major determinant of successful volume acquisition.

Accuracy of ultrasonography at 11-14 weeks of gestation for detection of fetal structural anomalies: a systematic review

OBJECTIVE

To review the literature concerning the efficacy of early ultrasonography (at 11-14 weeks of gestation) to identify fetal malformations.

DATA SOURCES

A search in PubMed, MEDLINE, Embase, Cochrane Library, and ClinicalTrials.gov was performed (January 2000 to December 2012). Keywords were: fetal anatomy, fetal echocardiography, nuchal translucency, fetal structural anomalies, fetal malformations, prenatal diagnosis, prenatal screening, and first-trimester ultrasonography.

METHODS OF STUDY SELECTION

Inclusion criteria were: fetal anatomy examination at early ultrasonography and diagnosis of fetal malformations confirmed by postnatal or postmortem examination. Data abstracted were: sample size, location of structural defect, ultrasound modality, presence of multiple defects, and study population. Pooled detection rate was calculated for each malformation and compared with χ. Differences were considered statistically significant if P<.05.

TABULATION, INTEGRATION, AND RESULTS

From 1,203 articles, 19 were included. Overall, we pooled 78,002 fetuses undergoing ultrasonography at 11-14 weeks, of which 996 were malformed, leading to prevalence of malformation of 12 per 1,000. The overall detection rate was 472 of 957 (51%). The highest detection rate was achieved for neck anomalies (92%), whereas limbs (34%), face (34%), and genitourinary anomalies (34%) were associated with the lowest detection rate. At 14 weeks of gestation or less, fetal echocardiography detected 53% of congenital heart disease compared with 43% by complete scan (P=.040). The use of Doppler did not improve the detection rate for congenital heart defects (52% compared with 44%, respectively; P=.11). Multiple defects were identified more frequently than isolated malformations (60% compared with 44%; P=.005). The detection rate was higher combining transabdominal and transvaginal techniques (62%) than either abdominal (51%) or transvaginal (34%; P<.001). Detection rate was higher in women at high risk (65%) than unselected population (50% P=.001).

CONCLUSION

Because of the natural history of fetal defects and the late development of some organ systems, a number of fetal malformations remain undetected by early ultrasonography.

Evaluation of the fetal heart at 14 to 18 weeks' gestation in fetuses with a screening nuchal translucency greater than or equal to the 95th percentile

OBJECTIVES

The purpose of this study was to determine whether normal fetal cardiac anatomy could be successfully demonstrated and congenital heart disease detected transabdominally at 14 to 18 weeks' gestation in fetuses with a nuchal translucency greater than or equal to the 95th percentile.

METHODS

In this retrospective chart review, grayscale images, Z scores, and Doppler evaluations, including pulsed, color, and spectral Doppler imaging, were reviewed to determine whether fetal heart evaluation findings at 14 to 18 weeks' gestation were normal or abnormal.

RESULTS

Normal cardiac anatomy was successfully evaluated in 32 of 33 normal cases; only an aortic arch and a ductal arch were not successfully visualized in 1 case. Major congenital heart disease was detected prenatally in 4 abnormal cases.

CONCLUSIONS

The fetal heart can be successfully evaluated at an earlier gestational age but may be dependent on the skill of the sonographer and reading physician. Maternal decisions can be made earlier in gestation, before the pregnancy is obvious, and can allow planning for a pregnancy that will need to be delivered at a medical center that has a level 3 nursery.

Fetal heart defects: potential and pitfalls of first-trimester detection

Congenital heart defects (CHDs) are the leading cause of infant mortality due to birth defects. In the last 15 years, with the shift in screening for aneuploidies to the first trimester, extensive research has concentrated on early screening and detection of CHDs. Early detailed assessment of the fetal heart requires a high level of expertise in early anomaly scanning and fetal echocardiography. However, the detection of major CHDs at 11-13 weeks is influenced by their association with easily detectable markers, such as the nuchal translucency, ductus venosus blood flow and tricuspid regurgitation, and a policy decision as to the objectives of this scan and the allocation of resources necessary to achieve them. The use of transvaginal ultrasound and newer techniques are likely to improve the detection rate. However, the limitations of fetal echocardiography in the first trimester must be borne in mind, and follow-up at mid-gestational echocardiography is prudent in some cases.

Performance of different scan protocols of fetal echocardiography in the diagnosis of fetal congenital heart disease: a systematic review and meta-analysis

OBJECTIVE

The rapid progress in fetal echocardiography has lead to early detection of congenital heart diseases. Increasing evidences have shown that prenatal diagnosis could be life saving in certain cases. However, there is no agreement on which protocol is most adaptive diagnostic one. Thus, we use meta-analysis to conduct a pooled performance test on 5 diagnostic protocols.

METHODS

We searched PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials and WHO clinical trails registry center to identify relevant studies up to August, 2012. We performed meta-analysis in a fixed/random-effect model using Meta-disc 1.4. We used STATA 11.0 to estimate the publication bias and SPSS 17.0 to evaluate variance.

RESULTS

We use results from 81 studies in 63 articles to analyze the pooled accuracy. The overall performance of pooled sensitivities of spatiotemporal image correlation (STIC), extend cardiac echography examination (ECEE) and 4 chambers view + outflow tract view + 3 vessels and trachea view (4 CV+OTV+3 VTV) were around 0.90, which was significant higher than that of 4 chambers view + outflow tract view or 3 vessels and trachea view (4 CV+OTV/3 VTV) and 4 chambers view (4 CV). Unfortunately the pooled specificity of STIC was 0.92, which was significant lower than that of other 4 protocols which reached at 1.00. The area under the summary receiver operating characteristic curves value of STIC, ECEE, 4 CV+OTV+3 VTV, 4 CV+OTV/3 VTV and 4 CV were 0.9700, 0.9971, 0.9983, 0.9929 and 0.9928 respectively.

CONCLUSION

These results suggest a great diagnostic potential for fetal echocardiography detection as a reliable method of fetal congenital heart disease. But at least 3 sections view (4 CV, OTV and 3 VTV) should be included in scan protocol, while the STIC can be used to provide more information for local details of defects, and can not be used to make a definite diagnosis alone with its low specificity.

Echocardiography in Early Pregnancy

Within the last decade, two significant events have contributed to the increasing interest in early fetal echocardiography. First, the introduction of high frequency vaginal ultrasound probes allows detailed visualization of cardiac structures at early stage of gestation, making early detection of fetal malformations possible. Second, the close relationship observed between some first trimester sonographic and Doppler markers and congenital heart defects allows an early identification of a high-risk group at 11 to 14 weeks of gestation. In this context, from the early 1990s, many authors have examined the potential role of the transvaginal approach to obtain earlier diagnosis of fetal cardiac malformations. Further studies have appeared in the literature showing that early transvaginal echocardiography in experienced hand is a fairly sensitive investigative tool. Although some malformations are detected as early as 11 weeks’ gestation, the optimal gestational age to perform the early scan is at least 13 weeks’ gestation. Transvaginal ultrasound is the preferred approach, although most of the authors agree that results can be improved if transabdominal ultrasound is also incorporated. The further application of color Doppler enhances visualization. The sensitivity and specificity of early fetal echocardiography for the detection of heart anomalies is acceptable compared to the ones obtained by mid-gestational echocardiography, showing a slight reduction in detection rates and an increase in false positive and negative rates. The cardiac anomalies detected at this early stage of pregnancy are mainly defects involving the four-chamber view, indicating that defects solely affecting the outflow tracts are difficult to diagnose in the first trimester of pregnancy. Heart defects diagnosed early in pregnancy tend to be more complex than those detected later, with a higher incidence of associated structural malformations, chromosomal abnormalities and spontaneous abortions. The neonate follow-up or postmortem examination in case of termination of pregnancy (TOP) is essential to assess the actual role of early fetal echocardiography. At present, early fetal echocardiography is a promising technique, which can be of considerable value for patients at high-risk. This technique is, however, currently limited to a few specialized centers.

The aim of this review is to explore the possibilities of examining the fetal heart at this early stage of pregnancy. This article also present our experience in the first multicenter trial in early fetal echocardiography performed in Spain. In accordance with other studies, this experience stresses the usefulness of early echocardiography when performed by expert operators on fetus specifically at risk for cardiac defects. Our review of these additional 48 cases contributes to the expanding literature on the ability of transvaginal ultrasonography to detect fetal heart defects in early pregnancy.

How to cite this article

Gabriel CC, Rodriguez PP. Echocardiography in Early Pregnancy. Donald School J Ultrasound Obstet Gynecol 2013;7(2):168-181.

Early fetal echocardiography: ready for prime time?

The objective of this study was to examine the performance of early fetal echocardiography as a screening tool for major cardiac defects in a high-risk population. Fetal echocardiograms performed at 12 to 16 weeks were reviewed. Cases that did not undergo a follow-up echocardiogram at 18 to 22 weeks were excluded. Results of the early and follow-up echocardiograms were compared. Over a 4-year period, 119 early fetal echocardiograms were recorded. Of those, 81 (68%) had follow-up fetal echocardiograms. Results of the early echocardiogram were normal in 77 of 81 (95.1%) cases. Of these, the follow-up was normal in 75 of these 77 cases; in the remaining 2, the follow-up raised suspicion for a ventricular septal defect (VSD) in one and persistent left superior vena cava in the other. On the other hand, the early echocardiogram was abnormal in 4 (4.9%) cases: (1) atrioventricular canal defect, with the follow-up demonstrating a VSD; (2) hypoplastic right ventricle and transposition of the great arteries, confirmed on follow-up; (3) VSD and coarctation of the aorta, confirmed on follow-up. In the fourth case, the early echocardiogram suspected a VSD and right-left disproportion, yet the follow-up was normal. In conclusion, early fetal echocardiography appears to be a reasonable screening tool for major cardiac defects.

Use of a high-frequency linear transducer and MTI filtered color flow mapping in the assessment of fetal heart anatomy at the routine 11 to 13 + 6-week scan: a randomized trial

OBJECTIVE

To prospectively assess the contribution of a high-frequency linear transducer and of moving target indicator (MTI) filtered color flow mapping in the visualization of cardiac fetal anatomy at the routine 11 to 13 + 6-week scan.

METHODS

This was a cross-sectional prospective study, including 300 singleton fetuses at 11 to 13 + 6 weeks' gestation. Patients were randomized into four groups and a detailed fetal cardiac examination was conducted transabdominally using either a conventional curvilinear transducer, a conventional curvilinear transducer and MTI filtered color flow mapping, a high-frequency linear transducer or a high-frequency linear transducer and MTI filtered color flow mapping. Regression analysis was used to investigate the effect on the ability to visualize different cardiac structures of the following parameters: gestational age at ultrasound examination; fetal crown-rump length (CRL); maternal body mass index (BMI); transducer-heart distance; the technique used at ultrasound; and the position of the placenta.

RESULTS

The four-chamber view was visualized in 89.0% of fetuses and regression analysis showed this rate was correlated with CRL and the use of MTI filtered color flow mapping during ultrasonography, and inversely correlated with BMI and transducer-heart distance. Use of a conventional curvilinear transducer and MTI filtered color flow mapping allowed visualization of the four-chamber view in 97.3% of fetuses, while this was only possible in 84.0% of fetuses using a high-frequency linear transducer. The left and right outflow tracts were visualized in 62.3 and 57.7% of fetuses, respectively. Regression analysis showed that the ability to visualize the left or the right outflow tract was correlated with the use of MTI filtered color flow mapping during scanning and was inversely correlated with transducer-heart distance. The use of a conventional curvilinear transducer and MTI filtered color flow mapping allowed visualization of the left and right outflow tracts in 96.0 and 97.3% of fetuses, respectively, while this was only possible in 37.3 and 26.7% of fetuses using a high-frequency linear transducer.

CONCLUSIONS

During the routine 11 to 13 + 6-week scan, the use of MTI filtered color flow mapping but not of a high-frequency linear transducer, improves visualization of cardiac anatomy.

Congenital heart disease in a Chinese hospital: pre- and postnatal detection, incidence, clinical characteristics and outcomes

BACKGROUND

The pre- and postnatal detection rate, incidence, clinical characteristics and outcomes of congenital heart disease (CHD) have been studied in developed countries for many years, but rarely have large-scale studies been reported in Chinese populations. The aim of the present study was to investigate the pre- and postnatal detection rates, incidence, clinical characteristics and outcomes of CHD in a Chinese hospital in order to improve the future screening and treatment of CHD.

METHODS

Fetuses without risk factors for CHD were screened using basic cardiac ultrasound examination (BCUE). Fetuses with suspected cardiac malformation revealed by BCUE and fetuses with risk factors were screened using extended cardiac ultrasound examination. Outcomes recorded from fetal, neonatal and postmortem records over 4 years (2006-2009) included: therapeutic termination of pregnancy, spontaneous abortions or stillbirths, deaths at birth or in the neonatal period (before 28 days of age), and rate of birth and clinical characteristics of newborns.

RESULTS

A total of 34,071 fetuses were screened for CHD during a period of 4 years, of which 173 fetuses were screened for CHD using BCUE and 301 fetuses were screened using extended cardiac ultrasound examination. The incidence of fetal CHD increased from 1.1% in 2006 to 2.4% in 2009 (P < 0.05), yielding an overall incidence of 1.5% (523/34,071). Of the fetuses with CHD, 48.2% (252/523) died before 28 days of age (including intra-uterine death and termination of pregnancy), 51.8% (271/523) lived more than 28 days and the incidence of live newborns with CHD was 0.80% (271/34071).

CONCLUSIONS

The prevalence of CHD was quite common in this Chinese hospital. Detailed profiles of CHD suggest that, while training programs in obstetric screening at this hospital were beneficial, prenatal intervention, treatment and care of fetal CHD were inefficient and should be strengthened in China.

Results of early foetal echocardiography and cumulative detection rate of congenital heart disease

OBJECTIVE

The aim of this study is to evaluate the cumulative detection rate of foetal echocardiography during gestation and in the early neonatal period, with a special emphasis on early foetal echocardiography.

METHODS

We conducted a retrospective survey of all singleton pregnancies from 1993 to 2007, with complete sequential echocardiography from 11 plus 0 to 13 plus 6 weeks of gestation. It was mandatory to have at least one foetal echocardiography in the second or third trimester and one postnatally.

RESULTS

Our study included 3521 pregnancies, in which 77 cases were diagnosed with congenital heart disease. Of them, 66 were detected in the first trimester - 11 plus 0 to 11 plus 6 weeks: 22 cases; 12 plus 0 to 12 plus 6 weeks: 23 cases; 13 plus 0 to 13 plus 6 weeks: 21 cases - with an 85.7% detection rate of congenital heart disease in early foetal echocardiography. In the second trimester, seven cases were found, with a detection rate of 9.1%. The third trimester reported two cases, with a detection rate of 2.6%. Postnatally, two (2.6%) cases were detected. The overall in utero detection rate of congenital heart disease was 97.4%.

CONCLUSIONS

Foetal echocardiography performed at the time of anomaly screening in the first trimester results in high detection rates of congenital heart disease. Cardiac pathology may evolve, and further examinations at later stages of pregnancy could improve the detection rate of congenital heart disease.

Defining the fetal cardiac axis between 11 + 0 and 14 + 6 weeks of gestation: experience with 100 consecutive pregnancies

OBJECTIVE

The purpose of this study was to establish normal fetal cardiac axis values during the first and early second trimesters of pregnancy.

METHODS

This was a prospective observational cohort study in which the fetal cardiac axis was assessed during ultrasound examinations in 100 consecutive fetuses between 11 + 0 and 14 + 6 weeks of gestation. Transabdominal, and, when indicated, transvaginal, approaches were used. Intraobserver and interobserver reproducibility were calculated.

RESULTS

The cardiac axis ranged from 34.5 to 56.8° (mean (SD) 47.6 ± 5.6°) in 94 fetuses with normal cardiac anatomy. The fetal cardiac axis tended to be significantly higher in fetuses at 11 + 0 to 11 + 6 weeks of gestation than in fetuses at 12 + 0 to 14 + 6 weeks of gestation. Congenital heart defects were found in six out of 100 fetuses, four of which had abnormal cardiac axis values at 11 + 0 to 14 + 6 weeks of gestation.

CONCLUSION

Cardiac axis measurement is possible in the first and early second trimesters of pregnancy. The assessment of cardiac axis at an early gestational age may help to identify pregnancies at high risk for congenital heart defects. Copyright

Reliability of the first-trimester cardiac scan by ultrasound-trained obstetricians with high-frequency transabdominal probes in fetuses with increased nuchal translucency

OBJECTIVE

To examine prospectively the reliability of ultrasound-trained obstetricians performing a first-trimester fetal cardiac scan with high-frequency transabdominal probes, by confirming normal or abnormal heart anatomy, in pregnancies referred for increased nuchal translucency thickness (NT).

METHODS

Trained obstetric operators assessed the fetal heart in 133 fetuses with increased NT (> 95th centile) at 11-14 weeks of gestation. A high-frequency transabdominal probe was used to confirm or refute normal cardiac anatomy rather than to establish a specific diagnosis. Following this preliminary screening by the ultrasound-trained obstetrician, specialized fetal echocardiographers rescanned the fetal heart in order to confirm the accuracy of the obstetric operators' findings and to establish a diagnosis in abnormal cases. Fetal cardiologists repeated the examinations at 20 and 32 weeks of pregnancy. Postnatal follow-up lasted 2 years. Twelve fetuses with normal karyotype and normal anatomy were lost to follow-up.

RESULTS

A total of 121 fetuses with increased NT between 11 and 14 weeks' gestation were studied. Congenital heart disease (CHD) was detected in 20/121 (16.5%) fetuses. In addition, there were three with mild ventricular disproportion, the right ventricle being larger than the left, considered as a minor non-specific cardiac abnormality. CHD was associated with chromosomal anomalies in 12/20 (60%) cases. Among the 121 fetuses, there was agreement between ultrasound-trained obstetricians and fetal cardiologists in 116 (95.9%) of the cases, and the ultrasound-trained obstetricians correctly identified 18 cases with major cardiac defects. However, there was disagreement in five cases: two with small ventricular septal defects and three with ventricular disproportion.

CONCLUSIONS

Our results provide evidence that obstetricians, trained to study the heart in the second trimester, can also differentiate reliably between normal and abnormal heart findings in the first trimester, when using a high-frequency transabdominal ultrasound probe.

The nuchal translucency and the fetal heart: a literature review

In this overview the current knowledge of the relationship between an increased nuchal translucency (NT) measurement and fetal heart structure and function in chromosomally normal fetuses is reviewed. Relevant pathophysiological theories behind the increased NT are discussed. Fetuses with an increased NT have an increased risk for congenital heart disease (CHD) with no particular bias for one form of CHD over another. This risk increases with increasing NT measurement. Although the NT measurement is only a modestly effective screening tool for all CHD when used alone, it may indeed be effective in identifying specific CHD "likely to benefit" from prenatal diagnosis. The combination of an increased NT, tricuspid regurgitation and an abnormal ductus venosus (DV) Doppler flow profile, is a strong marker for CHD. A fetal echocardiogram should be performed at 20 weeks' gestation in fetuses with an NT > or = 95th percentile but < 99th percentile. When the NT measurement is > or = 99th percentile, or when tricuspid regurgitation and/or an abnormal DV flow pattern is found along with the increased NT, an earlier echocardiogram is indicated, followed by a repeat scan at around 20 weeks' gestation. The resultant increased demand for early fetal echocardiography and sonographers with this special expertise needs to be planned and provided for.

Evaluation of first-trimester tricuspid regurgitation for Down syndrome screening

Screening for Down syndrome has become an integral part of prenatal care. In recent years, there has been significant interest in first-trimester screening methods. Increased nuchal translucency in the first trimester of pregnancy has been identified as a marker for chromosomal anomalies and congenital cardiac disease. In addition, research has identified a correlation between tricuspid regurgitation, diagnosed by pulsed-wave Doppler ultrasonography, in aneuploid fetuses between 11 and 13 + 6 weeks' gestation. This article provides a brief historical overview of screening for aneuploidy and examines the emerging trend and pitfalls of first-trimester screening.

First and early second trimester fetal heart screening

PURPOSE OF REVIEW

This review describes the recent advances in timing and effectiveness of first and early second trimester fetal echocardiography screening.

RECENT FINDINGS

Fetal echocardiography can now be reliably performed from 11 weeks' gestation owing to improvements in ultrasound transducers and processors. Three-dimensional and four-dimensional ultrasound modalities in image acquisition and postprocessing analysis, including spatio-temporal image correlation, rendering three-dimensional power Doppler and high definition power flow Doppler, and B-flow have further improved our capabilities in this area. Fetal nuchal translucency measurement screening programs create a new population of at-risk pregnancies that will be referred for early fetal echocardiography. The majority of congenital heart defects, however, still occur in low-risk patients. Improved technology has lowered the gestational age at which fetal cardiac anatomy scanning can be reliably performed by properly trained and experienced examiners.

SUMMARY

Early fetal echocardiography can be offered as a screening examination to at-risk and low-risk patients, with the proviso that it be repeated following screen-negative scans at mid-gestation to exclude later developing lesions.