Isolated major congenital heart disease

Clinical utility of fetal echocardiography: an Egyptian center experience

BACKGROUND

The impact of early diagnosis of fetal cardiac abnormalities on the postnatal outcome has been controversial in literature. We aimed to evaluate the role of fetal echocardiography (FE) as a diagnostic tool for early detection and proper management of fetal cardiac abnormalities, study the indications of referral and detect the perinatal outcome in our institution.

RESULTS

This is a cross-sectional observational and descriptive study that included one hundred and one singleton pregnant women (101 fetuses) who were referred for FE over a period of one year. Indications for referral and perinatal risk factors were documented. FE and postnatal transthoracic echocardiography were done. Fetal cardiac abnormalities were detected in 46.5% of cases. Congenital heart defects (CHDs) in 34.6%, fetal arrythmias in 9.9%, cardiomyopathy in 2.9% and cardiac mass (Rhabdomyoma) in 1% (combined structural and rhythm abnormalities were observed in two fetuses). Of the CHDs, complex heart lesions were diagnosed in 57.1%, common atrioventricular canal in 28.6% and conotrunchal anomalies in 14.3%. Of the ten cases with fetal arrythmias, five fetuses had tachyarrhythmias, four had ectopics and one fetus had congenital heart block in association with maternal lupus. The indications for referral were abnormal obstetric ultrasound (52.5%), maternal medical illnesses (23.8%), multiple neonatal deaths (13.9%) and positive family history of CHD (10.9%). The number of fetuses with cardiac abnormalities was significantly higher than those without cardiac abnormalities in mothers not exposed to perinatal risk factors (p = 0.009) and was statistically lower in mothers exposed to perinatal risk factors (p = 0.005). FE showed 100% accuracy in diagnosing complex lesions, common atrio-ventricular canals, cono-truncal anomalies, cardiac masses and fetal arrhythmias. It missed two cases of tiny muscular ventricular septal defects and one case of aortic coarctation. Cases of fetal supraventricular tachycardia were successfully treated in-utero.

CONCLUSIONS

CHDs exist in fetuses with no underlying perinatal risk factors. FE can accurately diagnose most of the cardiac anomalies though few errors remain challenging (aortic coarctation). It also offers a good chance for successful early life-saving management of some types of fetal arrhythmia.

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.

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.

Prenatal diagnosis of congenital heart defects and voluntary termination of pregnancy

BACKGROUND

The prenatal diagnosis of an isolated congenital heart defect is a matter of concern for parents. The decision of whether to terminate the pregnancy according to the different types of congenital heart defects has not been investigated yet.

OBJECTIVE

This study aimed to evaluate the frequency of voluntary termination of pregnancy after the prenatal diagnosis of a congenital heart defect in a tertiary care center.

STUDY DESIGN

This was a retrospective study of patients who were referred to our center from January 2013 to December 2019, underwent fetal echocardiography, and were counseled by a perinatologist and a pediatric cardiologist. The following data were collected: prenatal diagnosis, including genetic testing; gestational age at diagnosis; and outcome of pregnancy. The diagnoses were stratified retrospectively according to the type of congenital heart defect and its severity (low complexity, moderate complexity, and high complexity) by a perinatologist and a pediatric cardiologist.

RESULTS

Of 704 women who received a diagnosis of fetal congenital heart defect, 531 (75.4%) were seen before 23 weeks' gestation, which is the upper limit imposed for the termination of pregnancy by the Italian legislation. Congenital heart defects were apparently isolated in 437 of 531 cases (82.3%). Overall, 108 of 531 patients (20.3%) requested a termination of pregnancy. The rate of termination of pregnancy was found to vary according to the severity of congenital heart defects: low complexity, 0%; moderate complexity, 12.1%, and high complexity, 33.2% (P<.001). The presence or absence of associated anomalies or the ethnicity of the couples was not found to have an influence on women's decisions.

CONCLUSION

In our population, the decision to terminate a pregnancy after the diagnosis of a fetal congenital heart defect is influenced by the surgical complexity of the congenital heart defect itself. However, most patients, including those with the most severe forms of congenital heart defect, decided to continue the pregnancy.

Prenatal diagnosis of birth defects and termination of pregnancy in Hunan Province, China

OBJECTIVE

The aim of this study was to analyse the characteristics of the prenatal diagnosis (PD) of birth defects (BDs) and termination of pregnancy (TOP) for fetal anomalies and to suggest perinatal management.

METHODS

BD surveillance data were collected from 52 registered hospitals in Hunan between 2015 and 2018. The PD and TOP rates of BDs were calculated to examine the associations between infant sex, maternal age, and region.

RESULTS

From 2015 to 2018, a total of 18 931 fetuses with BDs were identified, of which 10 299 fetuses (54.4%) were diagnosed prenatally and 9343 pregnancies (90.7% among PDs and 49.3% among BDs) were terminated. The mean gestational age at diagnosis for fetuses with BDs was 25.1 ± 5.9 weeks and showed a downward trend over the study period. The average PD rate of the BDs was higher in rural areas than in urban areas (58.1% vs 50.3%), higher for female than male fetuses (57.25% vs 48.92%), and higher for mothers older than age 35 than for those younger (58.62% vs 53.69%). The average TOP rate of fetuses with BDs in rural areas was higher than that in urban areas (91.99% vs 89.12%) and decreased with increasing maternal age ( x trend 2 = 7.926, P = .005). The five BDs with the highest PD rates were conjoined twins (100%), anencephaly (97.87%), congenital hydrocephalus (97.66%), chromosomal malformation (96.07%), and encephalocele (95.54%). The five BDs with the highest TOP rates among the PDs were conjoined twins (100%), exstrophy of the urinary bladder (100%), chromosomal malformation (98.09%), encephalocele (98%), and anencephaly (97.28%).

CONCLUSIONS

More than half of BDs were diagnosed prenatally, with the majority diagnosed at less than 28 gestational weeks. The TOP rates following PD in Hunan Province were high, especially for rural and younger mothers. The findings suggest a need for high-quality, targeted counselling following PD.

Congenital fetal heart defect - an agreement between fetal echocardiography and autopsy findings

AIMS

To determine the frequency of pregnancy terminations due to prenatal congenital heart defect (CHD) and assess the agreement fetal echocardiography (FECHO) and autopsy findings.

METHODS

The data were retrospectively assessed between 2008 and 2017 in a population of 116 698 live births. The correlations between the FECHO and autopsy findings were classified into five levels of agreement: complete, partial, altered diagnosis, disagreement, and unfeasible autopsy.

RESULTS

Totally, 293 CHDs were identified and 49% of families (143/293) decided to terminate the pregnancy. In 1% (2/143) of cases, the autopsy could not be performed, for the other 99% (141/143), the pathologist confirmed the presence of CHDs. Complete agreement between FECHO and autopsy was achieved in 85% (122/143). In 10% (14/143) of cases, the pathologist found minor findings, which were not described in the FECHO. In 4% (5/143) of cases, the pathologist changed the main diagnosis.

CONCLUSION

Altogether, the results indicated that FECHO is a highly sensitive method for the prenatal detection of CHD but is incapable of detecting the complete spectrum of cardiac defects. Autopsies verified the diagnosis, confirmed the overall impairment in the fetus, and provided data for further counselling of the affected family.

Sensitivity, specificity, and accuracy of fetal echocardiography for high-risk pregnancies in a tertiary center in Egypt

BACKGROUND

Advances in fetal echocardiography training among pediatric cardiologists have led to substantial improvements in prenatal detection of congenital heart diseases (CHDs). Nevertheless, diagnostic accuracy varies among centers. Moreover, this subspecialty continues to evolve in developing countries, with limited studies assessing fetal echocardiography sensitivity, specificity, and accuracy in developing countries such as Egypt.

SUBJECT AND METHODS

High-risk pregnancies referred for fetal echocardiography from January 2011 to January 2019 were analyzed retrospectively. All of the cases included had one of the high-risk indications for fetal echocardiography. Maternal age and gestational age at the prenatal diagnosis were determined, and detailed fetal and neonatal echocardiograms were documented. The results of fetal and postnatal echocardiography were compared to assess the sensitivity, specificity, and accuracy of fetal echocardiography. A minor lesion was defined when no postnatal intervention was needed and a major anomaly when postnatal cardiac therapy, surgery, or intervention was required.

RESULTS

Out of 615 pregnant patients referred, comparisons between fetal and neonatal echocardiography were possible in 458 fetuses, with 157 patients excluded from the study. The mean maternal age in the study was 26.97±5.871 years and the mean gestational age at referral was 27.24±5.407 weeks. The most common indication for prenatal echocardiography in this cohort was a family history of CHD (142; 31%) followed by nonimmune hydrops (97; 21.18%) and abnormal obstetrical ultrasound screening (64; 13.97%). We had three false-positive minor diagnoses and four false-negative cases with only one requiring intervention. Prenatal diagnosis in this study was accurate in 98.47% of cases. The sensitivity, specificity, and accuracy of fetal echocardiography in the current work were 97.03%, 99.07%, and 98.47, respectively.

CONCLUSION

Fetal echocardiography is considered a highly sensitive specific tool for prenatal detection of congenital heart diseases in high-risk pregnancies even in developing countries. However, minor fetal cardiac disorders are challenging to diagnose and family counseling should emphasize the difficulty of excluding or confirming such lesions.

Parents' request for termination of pregnancy due to a congenital heart defect of the fetus in a country with liberal interruption laws

Objectives: This study aimed to evaluate the prenatal rate of congenital heart defects (CHDs) and the frequency of termination of pregnancy (TOP) due to a CHD, depending on the severity of the defect and concomitant diseases of the fetus.Methods: The data were assessed retrospectively between 2002 and 2017. Ultrasound examination was performed mostly in the second trimester. For analysis, the CHDs were divided into three groups of severity and three groups of fetus impairment.Results: A total of 40,885 fetuses underwent echocardiography. The CHDs were detected in 1.0% (398/40,885) and were an isolated anomaly in 69% (275/398). Forty-nine percent (197/398) of families decided to TOP. In all groups of severity, the rate of TOP rose linearly when comparing isolated defects and cases with associated morphological and genetic impairments. The TOP was significantly dependent on the associated anomalies in patients with the most correctable defects (p < .001) and the severity of CHDs in isolated cases without any other impairment (p < .001).Conclusion: The parents' decision to terminate increased with the severity of the defect and the associated anomalies of the fetus. The parents were mostly influenced by the associated anomalies when the CHD was correctable, and genetic factors played a more important role than morphological ones.

Fetal Intelligent Navigation Echocardiography (FINE) Detects 98% of Congenital Heart Disease

OBJECTIVE

Fetal intelligent navigation echocardiography (FINE) is a novel method that automatically generates and displays 9 standard fetal echocardiographic views in normal hearts by applying intelligent navigation technology to spatiotemporal image correlation (STIC) volume data sets. The main objective was to determine the sensitivity and specificity of FINE in the prenatal detection of congenital heart disease (CHD).

METHODS

A case-control study was conducted in 50 fetuses with a broad spectrum of CHD (cases) and 100 fetuses with normal hearts (controls) in the second and third trimesters. Using 4-dimensional ultrasound with STIC technology, volume data sets were acquired. After all identifying information was removed, the data sets were randomly distributed to a different investigator for analysis using FINE. The sensitivity and specificity for the prenatal detection of CHD, as well as positive and negative likelihood ratios were determined.

RESULTS

The diagnostic performance of FINE for the prenatal detection of CHD was: sensitivity of 98% (49 of 50), specificity of 93% (93 of 100), positive likelihood ratio of 14, and negative likelihood ratio of 0.02. Among cases with confirmed CHD, the diagnosis with use of FINE completely matched the final diagnosis in 74% (37 of 50); minor discrepancies were seen in 12% (6 of 50), and major discrepancies were seen in 14% (7 of 50).

CONCLUSIONS

This is the first time the sensitivity and specificity of the FINE method in fetuses with normal hearts and CHD in the second and third trimesters has been reported. Because FINE identifies a broad spectrum of CHD with 98% sensitivity, this method could be used prenatally to screen for and diagnose CHD.

Associations between congenital heart defects and genetic and morphological anomalies. The importance of prenatal screening

AIM

To study congenital heart defects (CHDs), evaluate their relation to extra-cardiac pathologies, and assess the significance of prenatal diagnostics for heart diseases.

METHODS

Data from 1999-2017 were analyzed for the incidence of significant CHDs in fetuses (prenatal ultrasound/echocardiography) and children, including, where applicable, autopsy data and genetic evaluation.

RESULTS

Among 220,400 fetuses, 819 (3.7 cases per 1000) significant CHDs were observed. Of the total, 53% (435/819) of CHDs were diagnosed prenatally. The heart defect was an isolated impairment in 78% (640/819), associated with a genetic impairment in 16% (128/819), and with extra-cardiac malformations without genetic pathology in 6% (51/819). Chromosomal aberrations were diagnosed prenatally in 70% (90/128) of those affected and extra-cardiac conditions in 86% (44/51). The CHD and genetic pathology association was more frequent prenatally [21% (90/435) vs. postnatally: 10% (38/384; P<0.0001)], as was the association between CHD with other extra-cardiac pathology and a normal karyotype [prenatally: 10% (44/435) vs. postnatally: 2% (7/384; P<0.0001)].

CONCLUSION

Heart defects are most frequently isolated, with genetic and other extra-cardiac anomalies in about one third of cases, significantly linked to prenatal diagnostics.

Organogenesis and foetal haemodynamics during the normal gestation of healthy black-rumped agoutis (Dasyprocta prymnolopha, Wagler, 1831) bred in captivity

The objective of this study was to define the patterns of organogenesis and foetal haemodynamics during the normal gestation of healthy agoutis (Dasyprocta prymnolopha) kept in captivity. Thirty pregnant agoutis that ranged in size from small to medium and weighed between 2.5 and 3 kg underwent B-mode and Doppler ultrasonography for the biometric evaluation of the foetal organs. The foetal aortic blood flow proved to be predominantly systolic, and the measured flow velocity was 78.89 ± 2.95 cm/s, with a maximum pressure gradient of 2.12 ± 0.27 mmHg. The liver was characterized by its large volume, occupying the entire cranial aspect of the abdominal cavity, and it was associated cranially with the diaphragm and caudally with the stomach. The flow velocity in the portal vein was estimated to equal 12.17 ± 2.37 cm/s, with a resistivity index of 0.82 ± 0.05. The gallbladder was centrally located and protruded cranially towards the diaphragm. The spleen was visualized as an elongated structure with tapered cranial and caudal extremities, and the foetal kidneys were visualized bilaterally in the retroperitoneal region, with the right kidney positioned slightly more cranially than the left. The morphological characterization and hemodynamic analysis of the foetal organs of black-rumped agoutis via B-mode and Doppler ultrasonography allow determination of the vascular network and of reference values for the blood flow required for perfusing the anatomical elements essential for maintaining the viability of foetuses at different gestational ages.

Impact of changing indications and increased utilization of fetal echocardiography on prenatal detection of congenital heart disease

BACKGROUND

Antenatal diagnosis of congenital heart defects (CHD) can impact outcomes in neonates with severe CHD. Obstetric screening guidelines and the indications for fetal echocardiography (FE) have evolved in an attempt to improve the early prenatal detection of CHD. Analyzing yield for specific indications will help clinicians better stratify at-risk pregnancies.

METHODS

Retrospective cohort study of all FE performed between 2000 and 2010 at a single tertiary care academic medical center in New York City. A total of 9878 FE met inclusion criteria for our study. In cases of multiple gestations (MG), each fetus was counted as a separate study.

RESULTS

The number of new diagnosis of fetal CHD by FEs increased 200%. There was a statistically significant increase in those referred for suspected CHD, increased nuchal translucency (NT), MG, and suboptimal imaging (P < .001). The indication of "suboptimal imaging" (SO) not only accounted for 5.23% of all referrals from 2000 to 2002, compared to 22.26% of all referrals from 2008 to 2010 (P < .0001), but also had the lowest yield for diagnoses of CHD (P < .02).

CONCLUSIONS

Over the past decade, there has been an increase in utilization of FE with a proportional increase in prenatally diagnosed CHD. For indications such as suspected CHD, NT and MG increases in referrals have led to a proportionate increase in fetal diagnosis of CHD. SO as an indication has the lowest yield of fetal diagnosis of CHD. Antenatal detection of CHD may be improved by a change in obstetric imaging protocols to ensure appropriate referrals.

Efficacy of prenatal diagnosis of major congenital heart disease on perinatal management and perioperative mortality: a meta-analysis

BACKGROUND

There is no consensus on the effectiveness of prenatal diagnosis except for hospitalized outcomes. Hence, a meta-analysis of published literature was conducted to assess the effect of prenatal diagnosis.

METHODS

Literature review has identified relevant studies up to December 2013. A meta-analysis was performed according to the guidelines from the Cochrane review group and the PRISMA statement. Studies were identified by searching PubMed, Embase, the Cochrane Central Register of Controlled Trials and World Health Orgnization clinical trials registry center. Meta-analysis was performed in a fixed/random-effect model using Revman 5.1.1 according to the guidelines from the Cochrane review group and the PRISMA guidelines.

RESULTS

The results from 13 cohort studies in 12 articles were analyzed to determine the optimal treatment with the lower rate of perioperative mortality in prenatal diagnosis. The superiority of a prenatal diagnosis has been proven because the surgical procedure could be done in the early neonatal period (95% CI, -0.76, -0.40). The prenatal diagnosis has also remarkably reduced the preoperative and postoperative mortality rates in cases of transposition of the great arteries (95% CI=0.06, 0.80; 95% CI=0.01, 0.82, respectively), as well as the overall results with all subtypes (95% CI=0.18, 0.94; 95% CI=0.46, 0.94, respectively).

CONCLUSIONS

Prenatal diagnosis is effective in perinatal management with an earlier intervention for major congenital heart disease, but only results in a reduced perioperative mortality in cases of transposition of the great arteries. Further investigations are required to evaluate the effect of prenatal diagnosis on life quality during a long-term follow-up.

How to Acquire Cardiac Volumes for Sonographic Examination of the Fetal Heart: Part 2

The effective performance of fetal cardiac examination using spatiotemporal image correlation (STIC) technology requires 2 essential steps: volume acquisition and postprocessing. An important prerequisite is training sonologists to acquire high-quality volume data sets so that when analyzed, such volumes are informative. This article is part 2 of a series on 4-dimensional sonography with STIC. Part 1 focused on STIC technology and its features, the importance of operator training/experience and acquisition of high-quality STIC volumes, factors that affect STIC volume acquisition rates, and general recommendations on performing 4D sonography with STIC. In part 2, we discuss a detailed and practical stepwise approach for STIC volume acquisition, along with methods to determine whether such volumes are appropriate for analysis.

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

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

Imaging the first trimester heart: ultrasound correlation with morphology

First trimester sonography is a widely used technique to examine the foetus early in pregnancy. The desire to recognise complex anatomy already in early developmental stages stresses the need for a thorough knowledge of basic developmental processes as well as recognition of cardiac compartments based on their morphology. In this paper, we describe the possibilities and limitations of sonographic assessment of the foetal heart between 10 and 14 weeks of gestation and correlate this to morphology. Examples of the most commonly detected congenital anomalies are atrioventricular septal defects, transposition of the great arteries, and hypoplastic left heart, which are shown in this paper.

[Contribution of volume ultrasound in the evaluation and prenatal care of fetal cardiovascular anomalies]

OBJECTIVES

To highlight the value of 3D ultrasound in the prenatal assessment of fetal cardiovascular abnormalities.

PATIENTS AND METHODS

A retrospective offline analysis of volume datasets of fetuses diagnosed with cardiovascular anomalies by 2D ultrasound was performed.

RESULTS

Thirty-four fetuses with 38 cardiac malformations were evaluated. Mean gestational age at diagnosis was 26 weeks. Isolated cardiovascular malformations were detected in 23 fetuses. Extracardiac abnormalities were identified in eight fetuses. Ten terminations of pregnancy were performed.

CONCLUSION

Offline analysis of cardiovascular anomalies conferred significant diagnostic advantages over 2D ultrasound. 3D ultrasound is a valuable tool for the prenatal diagnosis and the management of congenital heart diseases.

'I-shaped' sign in the upper mediastinum: a novel potential marker for antenatal diagnosis of d-transposition of the great arteries

OBJECTIVES

To investigate the 'I-shaped' sign as a novel echocardiographic marker for antenatal diagnosis of d-transposition of the great arteries (dTGA) in routine cardiac examination, and to compare its prevalence in fetuses with dTGA, those with other congenital heart diseases (CHDs) and those with normal structural hearts.

METHODS

This retrospective evaluation involved 1134 fetuses undergoing echocardiography to screen for CHD over a 4-year period. I-shaped sign was defined as the characteristic appearance of the aortic arch, resembling the letter 'I', from the most anterior to the most posterior point of the descending aorta visible in the three vessels and trachea view. The frequency of this sign was evaluated in cases with dTGA, those with other cardiac defects and those with normal cardiac structures.

RESULTS

CHD was diagnosed in 671 (59.1%) cases, of which 31 (4.6%) had dTGA. I-shaped sign was observed in 30/31 (96.8%) cases of dTGA, compared with 31/640 (4.8%) cases with other cardiac anomalies, which included single ventricle with pulmonary atresia or severe pulmonary stenosis, hypoplastic left heart syndrome with aortic atresia, corrected transposition of the great arteries, and double outlet right ventricle with malposition of the great arteries. I-shaped sign was detected significantly more frequently in the dTGA group compared with the normal group and with the other CHDs group (both P < 0.001) and had 96.8% sensitivity and 97.1% specificity for diagnosis of dTGA. Importantly, I-shaped sign was never observed in fetuses with structurally normal hearts.

CONCLUSIONS

Detection on echocardiography of an extremely long vessel with a marked I-shape should raise suspicion of cardiac anomaly, especially dTGA. This marker may therefore aid in the prenatal diagnosis of dTGA during routine ultrasound examination.

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.

Routine use of color Doppler in fetal heart scanning in a low-risk population

Objectives. To investigate the detection rate of major fetal heart defects in a low-risk population implementing routine use of color Doppler. Material and Methods. In a prospective observational study, all women undergoing fetal heart scanning (including 6781 routine examinations in the second trimester) during a three-year period were included. First a gray-scale scanning was performed including assessment of the four-chamber view and the great vessels. Thereafter three cross-sectional planes through the fetal thorax were assessed with color Doppler. Results. Thirty-nine fetuses had major heart defects, and 26 (67%) were prenatally detected. In 9/26 (35%) of cases the main ultrasound finding was related to the use of color Doppler. The survival rate of live born children was 91%. Conclusions. Routine use of color Doppler in fetal heart scanning in a low-risk population may be helpful in the detection of major heart defects; however, still severe malformations were missed prenatally.

Simple targeted arterial rendering (STAR) technique: a novel and simple method to visualize the fetal cardiac outflow tracts

OBJECTIVE

To describe a novel and simple technique—simple targeted arterial rendering (STAR)—to visualize the fetal cardiac outflow tracts from dataset volumes obtained with spatiotemporal image correlation (STIC) and applying a new display technology (OmniView).

METHODS

We developed a technique to image the outflow tracts by drawing three dissecting lines through the four-chamber view of the heart contained in a STIC volume dataset. Each line generated the following plane: (a) Line 1: ventricular septum en face with both great vessels (pulmonary artery anterior to the aorta); (b) Line 2: pulmonary artery with continuation into the longitudinal view of the ductal arch; and (c) Line 3: long-axis view of the aorta arising from the left ventricle. The pattern formed by all three lines intersecting approximately through the crux of the heart resembles a star. The technique was then tested in 50 normal fetal hearts at 15.3–40.4 weeks' gestation. To determine whether the technique could identify planes that departed from the normal images, we tested the technique in four cases with proven congenital heart defects (ventricular septal defect (VSD), transposition of great vessels, tetralogy of Fallot and pulmonary atresia with intact ventricular septum).

RESULTS

The STAR technique was able to generate the intended planes in all 50 normal cases. In the abnormal cases, the STAR technique allowed identification of the VSD, demonstrated great vessel anomalies and displayed views that deviated from what was expected from the examination of normal hearts.

CONCLUSIONS

This novel and simple technique can be used to visualize the outflow tracts and ventricular septum en face in normal fetal hearts. Inability to obtain expected views or the appearance of abnormal views in the generated planes should raise the index of suspicion for congenital heart disease involving the great vessels and/or the ventricular septum. The STAR technique may simplify examination of the fetal heart and could reduce operator dependency.

Prenatal diagnosis of truncus arteriosus using multiplanar display in 4D ultrasonography

Prenatal diagnosis of truncus arteriosus with two-dimensional sonography requires expertise in fetal echocardiography. Indeed, truncus arteriosus shares with tetralogy of Fallot and pulmonary atresia with a ventricular septal defect (VSD) the sonographic finding of a single arterial trunk overriding a VSD. The diagnosis of truncus arteriosus can be confirmed when either the main pulmonary artery or its branches are visualized arising from the truncus itself. This requires sequential examination of multiple scanning planes and a process of mental reconstruction of their spatial relationships. The advantage of multiplanar imaging in three-dimensional and four-dimensional ultrasonography is that it allows for the simultaneous visualization of three orthogonal anatomic planes, which can be very important in diagnosing cardiac abnormalities. We report, first, a case of truncus arteriosus diagnosed in utero where the multiplanar display modality provided important insight into the differential diagnosis of this conotruncal anomaly, and then, review the diagnosis of truncus arteriosus on ultrasound.

Intra- and interobserver repeatability of fetal cardiac examination using four-dimensional spatiotemporal image correlation in each trimester of pregnancy

OBJECTIVE

To assess the intra- and interobserver repeatability of the evaluation of fetal cardiac structures and measurements using spatiotemporal image correlation (STIC) technology in each trimester of pregnancy.

METHODS

Four-dimensional (4D)-STIC volumes from 150 low-risk pregnancies were acquired at first-, second- or third-trimester scan for later analysis by two different reviewers. A total of 19 items, including the evaluation of 14 structures as well as five measurements of the fetal heart, were evaluated. The reliability of qualitative variables was evaluated using Cohen's kappa and absolute agreement analysis while that of quantitative parameters was assessed using the intraclass correlation coefficient (ICC).

RESULTS

Forty-five, 47 and 47 STIC volumes were included in the final analysis from the first, second and third trimesters, respectively. For the evaluation of cardiac structures, good or excellent intra- and interobserver agreement (kappa > 0.6) was obtained in 12/14 and 9/14, respectively, while absolute agreement was > 90% for most structures evaluated. Regarding the quantitative cardiac measurements, ICC values were above 0.90 for all but cardiac axis (intraobserver ICC, 0.81 and interobserver ICC, 0.61). There were no significant differences in the repeatability values observed for qualitative or quantitative parameters among the trimesters of pregnancy.

CONCLUSION

Cardiac examination from 4D-STIC volumes showed a high repeatability between and within observers in each trimester of pregnancy.

Four-dimensional fetal echocardiography with spatiotemporal image correlation (STIC): A systematic study of standard cardiac views assessed by different observers

OBJECTIVE

To test the agreement between observers and reproducibility of a technique to display standard cardiac views of the left and right ventricular outflow tracts from four-dimensional volume datasets acquired with Spatiotemporal Image Correlation (STIC).

METHODS

A technique was developed to obtain dynamic multiplanar images of the left ventricular outflow tract (LVOT) and right ventricular outflow tract (RVOT) from volume datasets acquired with STIC. Volume datasets were acquired from fetuses with normal cardiac anatomy. Twenty volume datasets of satisfactory quality were pre-selected by one investigator. The data was randomly assigned for a blinded review by two independent observers with previous experience in fetal echocardiography. Only one volume dataset was used for each fetus. After a training session, the observers obtained standardized cardiac views of the LVOT and RVOT, which were scored on a scale of 1 to 5, based on diagnostic value and image quality (1=unacceptable, 2=marginal, 3=acceptable, 4=good, and 5=excellent). Median scores and interquartile range, as well as inter- and intraobserver agreement were calculated for each view.

RESULTS

The mean menstrual age at the time of volume acquisition was 25.5+/-4.5 weeks. Median scores (interquartile range) for LVOT images, obtained by the first and second observers, were 3.5 (2.25-5.00) and 4 (3.00-5.00), respectively. The median scores (interquartile range) for RVOT images obtained by the first and second observers were 3 (3.00-5.00) and 3 (2.00-4.00), respectively. The interobserver intraclass correlation coefficient for the LVOT was 0.693 (95% CI 0.380-0.822), and 0.696 (95% CI 0.382-0.866) for the RVOT. For the intraobserver agreement analysis, observer 1 gave higher scores to the LVOT the second time the volumes were analyzed [LVOT: 3.50 (2.25-5.00) vs. 5.00 (4.00-5.00, p=0.008)].

CONCLUSION

STIC can be reproducibly used to evaluate fetal cardiac outflow tracts by independent examiners. Slightly better image quality rating scores during the intraobserver variability trial suggests the presence of a learning curve for the manipulation and analysis of volume data obtained by STIC.

Prenatal screening for major congenital heart disease: superiority of outflow tracts over the 4-chamber view

OBJECTIVE

The purpose of this study was to determine the relative importance of the 4-chamber view (4CV) compared with the outflow tract views (OFTVs) in prenatal screening for major congenital heart disease (CHD).

METHODS

We prospectively evaluated 200 consecutive infants undergoing cardiac surgery at our institution for major CHD. By reviewing the infants' medical records and conducting bedside interviews with their parents or guardians, we evaluated detection rates both prenatally and postnatally (before and after discharge to home), and we noted any prenatally identifiable risk factors for CHD. For each infant, we determined whether the 4CV or OFTVs would be expected to have been normal or abnormal on routine midgestation screening fetal sonography.

RESULTS

A prenatal diagnosis of CHD was made in 65 infants (33%): 30 of 124 low-risk pregnancies (24%) and 35 of 76 high-risk pregnancies (46%). An abnormal screening midgestation 4CV would have been expected in up to 63% of the infants, whereas abnormal midgestation OFTVs would have been expected in up to 91% of the infants. Thus, the potential sensitivity for detecting major CHD was higher with the OFTVs than with the 4CV (91% versus 63%; P < .001). Moreover, the OFTVs were more sensitive than the 4CV for detecting ductal-dependent forms of CHD. Diagnosis after discharge to home occurred in 39 of 135 postnatal diagnoses (29%), including many cases of isolated outflow tract abnormalities requiring early invasive intervention.

CONCLUSIONS

Cases of major neonatal CHD with OFTV abnormalities predominate over cases with 4CV abnormalities, particularly among those forms of CHD requiring early invasive intervention.

Feasibility of automated 3-dimensional fetal cardiac screening in routine ultrasound practice

OBJECTIVE

The purpose of this study was to prospectively assess the clinical feasibility of an automated 3-dimensional (3D) software tool for extended basic cardiac screening in routine ultrasound practice.

METHODS

During the 2-month study period, all gravidas fitting our inclusion criteria were consecutively included. Cardiac 3D volumes were acquired within the time slot allocated for the usual 2-dimensional fetal examination. All volumes were assessed on their quality, based on display of the 4-chamber view, and on the ability to sufficiently display diagnostic cardiac planes (left ventricular outflow tract [LVOT], right ventricle outflow tract [RVOT], and stomach location) with Sonography-Based Volume Computer-Aided Diagnosis software (SonoVCAD; GE Healthcare, Milwaukee, WI).

RESULTS

Volume acquisition was successful in 107 of 126 cases (85%). For each sonographer, more than 70% of the acquired cardiac volumes were of high or sufficient quality. Separately analyzed, diagnostic planes of the LVOT, RVOT, and stomach location were visible in 62.1%, 81.6%, and 92.2%, respectively. An extended basic fetal cardiac examination based on retrieval of all diagnostic cardiac planes from a single volume using SonoVCAD could be performed in 46.6% of the cases.

CONCLUSIONS

This study shows that cardiac volume acquisition can be incorporated in a routine ultrasound screening program without much difficulty. However, currently, SonoVCAD software still lacks the consistency to be clinically feasible for cardiac screening purposes. Further advances in ultrasound technology and familiarization with 3D ultrasound might improve its performance.

Evaluation of referral indications for fetal echocardiography in Beijing

OBJECTIVES

This study was conducted to evaluate the referral indications for fetal echocardiography (FE) in a tertiary center and to determine which indications were significantly associated with prenatal detection of congenital heart disease (CHD).

METHODS

The medical records of 1425 consecutive women who underwent second- and third-trimester FE at the Ultrasound Center of Beijing Obstetrics and Gynecology Hospital from March 2003 to December 2007 were reviewed. Referral indications, FE diagnoses, and pregnancy outcomes were collected. Univariate and multivariate logistic regression analyses were performed to identify those referral indications associated with prenatal detection of CHD.

RESULTS

In 126 patients (8.8%), CHD was detected prenatally and confirmed postnatally. Logistic regression analysis showed that abnormal cardiac views and extracardiac malformation findings (especially a single umbilical artery) on second-trimester ultrasound screening were found to have significantly more CHD (P < .001). The adjusted odds ratios were 15.2 (95% confidence interval, 9.85-23.45) and 6.78 (95% confidence interval, 2.38-19.27), respectively.

CONCLUSIONS

Abnormal cardiac views and extracardiac malformation findings on second-trimester ultrasound screening were significantly associated with prenatal detection of CHD.

A systematic analysis of the feasibility of four-dimensional ultrasound imaging using spatiotemporal image correlation in routine fetal echocardiography

OBJECTIVES

To investigate the feasibility of incorporating spatiotemporal image correlation (STIC) into a tertiary fetal echocardiography program.

METHODS

During the study period all pregnant women fitting our inclusion criteria were enrolled consecutively. Four sonographers participated in the study, one of whom had substantial previous experience of STIC volume acquisition and three of whom did not. STIC volumes were acquired within the time slot allocated for the usual examination and all attempts were recorded. STIC volumes were assessed on acquisition conditions, the quality (as defined by a checklist of cardiac structures that could be visualized), and the rendering abilities. Furthermore, possible learning effects and the influence of experience with STIC on volume acquisition were studied.

RESULTS

STIC volume acquisition was successful in 75.7% (112/148) of cases in which it was attempted. The more experienced sonographer had a higher success rate in STIC volume acquisition (experienced vs. less experienced, 88.4% vs. 70.5%, P = 0.02). Of all analyzed STIC volumes, 64.8% were of high or sufficient quality. STIC volume quality and rendering ability correlated strongly with the acquisition conditions. High-quality STIC volumes successfully rendered the intracardiac septa in 84.6% of cases. The coronal atrioventricular plane was rendered in 12/26 cases (46.2%).

CONCLUSIONS

This study shows that incorporation of STIC volume acquisition into the daily practice of a tertiary fetal echocardiography program is feasible. Sonographers do not have to be specifically experienced in three- or four-dimensional ultrasound imaging to acquire high-quality STIC volumes. For successful STIC acquisition and subsequent successful analysis, correct acquisition conditions are of major importance. Finally, our results demonstrate that STIC is as susceptible as conventional two-dimensional ultrasound imaging to individual variations and limitations in scanning windows.

Growth and Nutritional Status of Children With Congenital Heart Disease

BACKGROUND AND RESEARCH OBJECTIVE

Factors predictive of growth deficit and nutritional status in children with congenital heart disease remain unclear. The objective of this study was to characterize the growth and nutritional status of children with congenital heart disease based on anthropometric measurements and z scores.

SUBJECTS AND METHODS

One hundred and thirty-five children 1 year or younger, who had not undergone surgical correction, were evaluated. The variables studied were sex; age; type of heart disease; length, weight; z scores (length-for-age, weight-for-age, weight-for-length); abdominal, thoracic, and cephalic circumferences; triceps and subscapular skinfold thickness; and birth weight and birth length.

RESULTS AND CONCLUSIONS

The mean age of children in this study was 4.75 +/- 3.75 months and most (66.7%) were male. Mean anthropometric measurements were birth length, 48.6 +/- 2.34 cm; birth weight, 3.11 +/- 0.63 kg; cephalic circumference, 38.51 +/- 3.28 cm; thoracic circumference, 38.65 +/- 3.76 cm; abdominal circumference, 37.96 +/- 3.27 cm; triceps skinfold thickness, 3.69 +/- 1.57 mm; subscapular skinfold thickness, 3.22 +/- 1.34 mm; current length, 57.54 +/- 7.87 cm; and current weight, 4.46 +/- 1.49 kg. Variables significant for malnutrition in logistic regression models were sex, type of heart disease, birth weight, birth length, subscapular thickness, triceps thickness, and cephalic circumference. Nutritional defects were more evident in the case of the weight-for-age index. Boys had greater deterioration in the weight-for-age index, possibly indicating acute malnutrition, and girls had worse values for the height-for-age index, indicating a risk of chronic malnutrition.

Comparison of two- and three-dimensional ultrasonography in the evaluation of fetal heart: image quality and time spent in the exam

OBJECTIVES

To compare fetal heart evaluation done through two-dimensional (2DUS) and three-dimensional ultrasonography (3DUS) as to optimal plane imaging, image quality, and time needed to perform the examination.

METHODS

Prospective study involving 12 normal pregnant women, with gestational ages ranging from 22 to 26 weeks, scanned with a VOLUSON 730 with a convex 4.0-7.0 MHz transducer, in both two- and three-dimensional modes. In each case, three basic view planes were obtained: four-chambers view, right, and left ventricular outflow tracts. Each view was subjectively evaluated by three different examiners as to image quality, and graded from 0 (minimum) to 4 (maximum) cross-marks (+). The sum of all grades obtained for each case was used to classify the quality of the exam as unsatisfactory (0 to 1+), poor (2 to 4+), regular (5 to 7+), and good (8 to 12+). The time taken to obtain the views was recorded for each case, starting with the acquisition of the first view on the 2D exam and with the identification and opening of the volume blocks on the three-dimensional software.

RESULTS

The number of three-dimensional blocks with good, regular, poor, and unsatisfactory grades were, respectively, 6, 15, 9, and 10. The average in cross-marks of the cases graded good in each group without the worst result for each plane was 8. 2DUS was superior to 3DUS regarding the quality of the images obtained by the three pattern view planes and the average time to obtain high quality view planes was longer for 3DUS when compared to 2DUS. 2DUS offered better quality images and in less time than 3DUS.

CONCLUSIONS

Three-dimensional ultrasound is an advancement in fetal heart evaluation; however two-dimensional ultrasound remains the best screening method in diagnosing cardiac malformations, due to the good quality of its images and the lesser time needed to perform the exam.

Nuchal translucency measurement and congenital heart defects: modest association in low-risk pregnancies

OBJECTIVE

To assess the performance of nuchal translucency (NT) measurement in the first trimester of pregnancy as a marker for congenital heart defects (CHD) in the fetus in a low-risk obstetric population.

METHODS

Nuchal translucency screening was offered over a 3-year period to consecutive pregnant women without known a priori risk factors and attending midwife practices in three different areas in the Netherlands. In chromosomally normal fetuses and infants from the study population the NT measurements were matched with CHD detected either prenatally or postnatally.

RESULTS

NT screening was offered to 6132 women with an uptake of 83%. A total of 4876 NT measurements was performed. Pregnancy outcome data were available in 4181 cases (86%). Defects of the heart and great arteries (CHD) were diagnosed in 24 cases (prevalence 5.8/1000). Thirteen of these were classified as major (prevalence 3.1/1000). Two major CHD occurred in fetuses showing an increased NT at the first-trimester scan. The sensitivity of NT measurement > 95th and > 99th percentile for all CHD and for major CHD, was 8% and 15%, respectively. The positive likelihood ratios of NT > 95(th) and > 99th percentile for major CHD were 6, 5 and 33, respectively.

CONCLUSION

In pregnancies without known risk factors also, an increased NT is associated with major cardiac defects in the fetus and therefore represents an indication for specialized fetal echocardiography. However, this association is too weak to envisage a role for NT measurement as single screening strategy for the prenatal detection of cardiac defects.

The examiner's ultrasound experience has a significant impact on the detection rate of congenital heart defects at the second-trimester fetal examination

OBJECTIVES

To determine whether training and experience in performing ultrasound examinations are factors that influence the prenatal detection of congenital heart defects (CHDs) in a non-selected population, in order to evaluate and improve the current training program.

METHODS

All pregnant women who received a routine second-trimester ultrasound scan by a sonographer/midwife and delivered at our hospital between February 1991 and December 2001 were registered prospectively. Less experienced sonographer/midwives who had performed between 200 and 2000 routine examinations were compared with experienced sonographer/midwives who had carried out more than 2000 examinations. During the first 5 years of the study the heart structures obtained were registered in detail.

RESULTS

Of 29,035 fetuses, 35/82 (43%) major CHDs were prenatally detected at the routine examination. The experienced sonographer/midwives obtained both the four-chamber view and the great arteries in 75%; the figure for the less experienced sonographer/midwives was 36% (P < 0.001). The differences in detecting major heart defects were 22/42 (52%) and 13/40 (32.5%), isolated CHDs 8/18 (44%) and 6/22 (27%) and CHDs with associated malformations 14/24 (58%) and 7/18 (39%), respectively. In both groups some CHDs with an abnormal four-chamber view were missed, although the experienced sonographer/midwives recognized significantly more of the abnormal views than did the less experienced sonographer/midwives (P = 0.002).

CONCLUSIONS

Experience has a significant impact on the examination of the fetal heart and the prenatal detection rate of major CHDs. To avoid a relatively long learning curve, ultrasound education needs to intensify the teaching of the basic four-chamber view. The great arteries should be included after additional training. Those basic views of the fetal heart must be mastered before new views and advanced technology are added to the fetal heart examination.

Simple approach to prenatal diagnosis of transposition of the great arteries

OBJECTIVE

To analyze the most relevant anomalies, seen in a sequential segmental transverse views approach to imaging the fetal heart, that provide clues to the diagnosis of complete transposition of the great arteries (TGA).

METHODS

We reviewed retrospectively all the cases of isolated TGA diagnosed in our center or submitted for a second opinion through the spatio-temporal image correlation (STIC) telemedicine (TELE-STIC) program. Only transverse cardiac sweeps were obtained. Digital video clips and STIC volumes were reviewed. The abnormal features on four-chamber, five-chamber, three-vessel (3V) and three vessels and trachea (3VT) views were analyzed.

RESULTS

The study population consisted of eight fetuses with TGA with normal extracardiac anatomy. The gestational age ranged from 13 to 32 (mean, 23) weeks. The maternal age ranged from 25 to 42 (mean, 32) years. A normal four-chamber view was seen in seven cases. Only one case demonstrated a significant ventricular septal defect. At the level of the five-chamber view a straight course arterial vessel arose from the left ventricle with lateral branches in all fetuses. In the 3V view, the ascending aorta was seen reaching more anteriorly than was the pulmonary artery in six cases. At the level of the 3VT view, two vessels (transverse aortic arch and superior vena cava) rather than three were seen in all cases.

CONCLUSION

Our proposed sequential segmental approach to imaging the fetal heart apparently allows, in five-chamber and 3VT views, clear and confident signs to be detected that aid diagnosis of TGA.

Fetal atrioventricular valve junction in normal fetuses and in fetuses with complete atrioventricular septal defect assessed by 4D volume rendering

OBJECTIVES

To assess the feasibility and clinical potential of 4D volume rendering of the atrioventricular (AV) valve junction, to standardize the acquisition method, and to display the AV valve junction morphology in normal fetuses and in those with a complete atrioventricular septal defect (AVSD).

METHODS

We performed sonography in 40 normal fetuses and 10 fetuses with complete AVSD, and volume datasets were acquired from apical and lateral four-chamber views. The render box was placed systematically. First, it included the AV valves, with the reference dot at the level of the crux of the heart. Then, it included the papillary muscles, with the reference dot in the interventricular septum at the level of the distal opening of the tricuspid valve leaflet.

RESULTS

Volume acquisition and rendering were technically possible in all cases. Volume rendering of the left ventricle showed the position of the anterolateral and posteromedial papillary muscles in 36/40 normal fetuses (90%). At the level of the right ventricle, the septal, anterior and posterior papillary muscles were visualized in 33/40 normal fetuses (82%). In cases of complete AVSD, the AV valve has five leaflets, with anterosuperior and posteroinferior bridging leaflets straddling the septa. The morphology of the anterosuperior bridging leaflets and the abnormal position of the papillary muscles could be displayed in all cases.

CONCLUSIONS

Our study suggests that some of the components of the AV junction can be reconstructed easily from sonographic volumes acquired from an apical or lateral four-chamber view. This new technique may have a role in obtaining views that are not easily accessible by standard sonography, enabling a rapid complementary assessment of normal and abnormal intracardiac anatomy.

Four-dimensional ultrasonography of the fetal heart using a novel Tomographic Ultrasound Imaging display

OBJECTIVE

The objective of this study was to investigate the feasibility of examining the fetal heart with Tomographic Ultrasound Imaging (TUI) using four-dimensional (4D) volume datasets acquired with spatiotemporal image correlation (STIC).

MATERIAL AND METHODS

One hundred and ninety-five fetuses underwent 4D ultrasonography (US) of the fetal heart with STIC. Volume datasets were acquired with B-mode (n=195) and color Doppler imaging (CDI) (n=168), and were reviewed offline using TUI, a new display modality that automatically slices 3D/4D volume datasets, providing simultaneous visualization of up to eight parallel planes in a single screen. Visualization rates for standard transverse planes used to examine the fetal heart were calculated and compared for volumes acquired with B-mode or CDI. Diagnoses by TUI were compared to postnatal diagnoses.

RESULTS

(1) The four- and five-chamber views and the three-vessel and trachea view were visualized in 97.4% (190/195), 88.2% (172/195), and 79.5% (142/195), respectively, of the volume datasets acquired with B-mode; (2) these views were visualized in 98.2% (165/168), 97.0% (163/168), and 83.6% (145/168), respectively, of the volume datasets acquired with CDI; (3) CDI contributed additional diagnostic information to 12.5% (21/168), 14.2% (24/168) and 10.1% (17/168) of the four- and five-chamber and the three-vessel and trachea views; (4) cardiac anomalies other than isolated ventricular septal defects were identified by TUI in 16 of 195 fetuses (8.2%) and, among these, CDI provided additional diagnostic information in 5 (31.3%); (5) the sensitivity, specificity, positive- and negative-predictive values of TUI to diagnose congenital heart disease in cases where both B-mode and CDI volume datasets were acquired prenatally were 92.9%, 98.8%, 92.9% and 98.8%, respectively.

CONCLUSION

Standard transverse planes commonly used to examine the fetal heart can be automatically displayed with TUI in the majority of fetuses undergoing 4D US with STIC. Due to the retrospective nature of this study, the results should be interpreted with caution and independently confirmed before this methodology is introduced into clinical practice.

Ductus venosus Blood Flow Velocity Waveforms as a Predictor for Fetal Outcome in Isolated Congenital Heart Disease

OBJECTIVE

To investigate whether pulsatility of ductus venosus (DV) flow velocity waveforms is of diagnostic value in predicting survival in fetuses with congenital heart disease (CHD).

METHODS

In a cross-sectional study, Doppler investigation of DV and umbilical artery blood flow was performed in 58 fetuses with isolated structural CHD, without other sonographically detectable structural or chromosomal abnormalities or tachyarrhythmia. The pulsatility index for veins of DV (DV-PIV) waveforms was expressed as multiples of the 95th centile (Mo95th) of the reference ranges for gestational age. The PIV was related to intrauterine and neonatal mortality within the first 6 months of life. Terminations of pregnancies and neonates with additional abnormalities detected after birth were excluded from statistical analysis. For statistical analysis, the different types of heart defects were separated into atrial and/or ventricular (AV) septal defects, right or left ventricular in- and outflow tract abnormalities and others.

RESULTS

After exclusion of 9 pregnancies (2 cases with failure of measurements of DV-PIV, 2 neonates with additional malformations, and 5 terminations of pregnancies), 49 cases were available for statistical analysis. The umbilical artery pulsatility index was within normal ranges in all but 1 case with AV canal and hydrops. In 7 pregnancies intrauterine fetal deaths occurred and 6 of them were hydropic. The median gestational age at birth for liveborn neonates was 39.0 weeks (range 27.8-41). There were 6 postnatal deaths, all but 1 within 28 days of delivery. The remaining fetuses survived for at least 6 months. The overall mortality rate was 27% (13/49). The DV-PIV was significantly higher in non-survivors than in survivors (median of Mo95th and interquartile ranges 1.48 (1.04-1.95) vs. 0.81 (0.70-1.15); p = 0.01). Analysis of subgroups showed significant differences for AV septal defects and abnormalities affecting predominantly the right ventricle (p = 0.046 and 0.043, respectively). Ten out of 13 non-survivors showed an abnormal DV-PIV (sensitivity 77%) as compared to 12 out of 36 survivors (specificity 67%). All hydropic fetuses (n = 6) showed an abnormal DV-PIV and ended in intrauterine deaths.

CONCLUSIONS

Evaluation of the DV pulsatility is a useful additional variable for predicting the risk for mortality in fetuses with isolated structural CHD, in particular in fetuses with defects of the AV septum and with defects affecting predominantly right ventricular function. As there is no fetal hydrops without abnormal DV, this is another sign for the association of DV and cardiac failure.

The syndrome of left isomerism: sonographic findings and outcome in prenatally diagnosed cases

OBJECTIVE

The purpose of this study was to evaluate the accuracy of the prenatal diagnosis of left isomerism and to assess possible diagnostic and prognostic markers.

METHODS

We conducted a retrospective review of all previously unpublished cases of left isomerism diagnosed in the prenatal and postnatal periods in 2 tertiary referral centers in Germany over 15 years.

RESULTS

Among 34 fetuses, 31 had a correct prenatal diagnosis of left isomerism; 31 had an interruption of the inferior vena cava with azygos continuation; 22 had different types of viscerocardiac heterotaxy; 13 had heart block; and 28 had cardiac defects, with a high prevalence of atrioventricular septal defects (n = 24), right outflow tract obstruction (n = 11), double-outlet right ventricles (n = 6), and anomalous pulmonary venous return (n = 6). Among the 34 cases, 9 underwent termination of pregnancy; 2 fetuses died in utero; 5 children died in the neonatal period; and 4 children died in infancy. Only the presence of heart block and hydrops was significantly correlated with nonsurvival (P < .05). Fourteen children survived, with a mean follow-up +/- SD of 2.9 +/- 2.6 years. Three survivors underwent single-ventricle palliation, and 1 had successful biventricular repair. Three children were awaiting cardiac repair. The remaining 7 children had minor or no associated cardiac defects and were doing well.

CONCLUSIONS

Prenatal diagnosis of left isomerism is feasible, with high accuracy. Important diagnostic pointers are viscerocardiac heterotaxy, complex cardiac malformations, heart block, and interruption of the inferior vena cava. The mortality in fetuses and neonates is high in the presence of heart block and hydrops, whereas the cardiac defects influence the long-term outcome.

Pre-natal counselling--helping couples make decisions following the diagnosis of severe heart disease

The prenatal diagnosis of a major cardiac abnormality tends to precipitate a crisis for the affected parents. In a setting of grief and emotional distress, there is the challenge to provide meaningful information of the abnormality, its need for intervention and likely outcome, so as to enable the parents, if allowed the option, to come to a fully informed decision as to whether to continue with the pregnancy. This discussion paper reviews the difficulties encountered in counselling affected parents being mindful of the psychological constraints prevalent at the time. While an accurate and detailed diagnosis is important for the professionals, the information required by the parents needs to be simple and focussed on the questions raised by them as they relate to quality of life issues to be experienced by their yet unborn infant/child growing into an adult.

Elevated first-trimester nuchal translucency increases the risk of congenital heart defects

OBJECTIVE

We sought to evaluate the association between first trimester nuchal translucency measurement and the risk for major congenital heart defect in chromosomally normal fetuses.

STUDY DESIGN

First trimester (10 weeks 4 days of gestation to 13 weeks 6 days of gestation) nuchal translucency was obtained in a large prospective multicenter National Institute of Child Health and Human Development study for Down syndrome prediction. The study, which was conducted between May 1998 and December 2000, was restricted to singleton pregnancies. Gestational age was determined by crown rump length measurements. Perinatal outcomes were determined and included the frequency of major congenital heart defect, which was defined as those cases that potentially could require surgery, intensive medical therapy, or prolonged follow-up time. Logistic regression analysis was used to determine whether nuchal translucency was a significant predictor of congenital heart defect.

RESULTS

There were 8167 chromosomally normal pregnancies, of which 21 cases of major congenital heart defect were identified at follow-up examination (incidence, 2.6/1000 pregnancies). The risk of congenital heart defect rose with increasing nuchal translucency measurements. The mean nuchal translucency value for the normal and congenital heart defect groups were 1.5 mm and 1.9 mm, respectively (P = .05). With a nuchal translucency measurement of < 2.0 mm, the incidence of congenital heart defect was 13 of 6757 pregnancies (1.9 of every 1000 pregnancies). At 2.0 to 2.4 mm, the incidence was 5 of 1032 pregnancies (4.8 of every 1000 pregnancies). At 2.5 to 3.4 mm, the incidence was 2 of 335 pregnancies (6.0 of every 1000 pregnancies). At > or = 3.5 mm, the incidence was 1 of 43 pregnancies (23 of every 1000 pregnancies). Logistic regression analysis confirmed that nuchal translucency was associated significantly with congenital heart defect (odds ratio, 2.1; 95% CI, 1.4-3.1; P = .0004).

CONCLUSION

Increased first trimester nuchal translucency measurement was associated with a higher risk of major congenital heart defect in chromosomally normal pregnancies. The practical implications of our findings are that patients with unexplained elevations of nuchal translucency may need referral for a fetal echocardiogram.

A new approach to fetal echocardiography: digital casts of the fetal cardiac chambers and great vessels for detection of congenital heart disease

OBJECTIVE

The purpose of this study was to describe a method of 4-dimensional (4D) reconstruction of the cardiac chambers and outflow tracts using a combination of spatiotemporal image correlation, "inversion mode," and "B-flow" imaging.

METHODS

Spatiotemporal image correlation and the inversion mode were used in the examination of the volume data sets of 23 fetuses with congenital heart anomalies. A subset was also examined with B-flow imaging using the gradient light algorithm. Digital reconstructions from abnormal hearts were compared with a library obtained from fetuses without abnormalities.

RESULTS

Rendered images of the 4-chamber view using the inversion mode were characterized by: (1) echogenic chambers; (2) sharp delineation of chamber contours when compared with 2-dimensional (2D) images; and (3) distinct display of the myocardium, interventricular septum, interatrial septum, and mitral and tricuspid valves as anechoic structures. Ventricular septal defects, abnormal differential insertion of the atrioventricular valves, and valve atresia were well visualized with the inversion mode. The application of inversion mode or B-flow imaging to 4D rendering of the outflow tracts resulted in "digital casts" displaying the spatial relationships between the outflow tracts as well as the connections between the great arteries and ventricular chambers. The spatial relationships and communications among cardiac structures cannot be visualized with conventional 2D ultrasonography.

CONCLUSIONS

The application of spatiotemporal image correlation, inversion mode, and B-flow imaging generates information about the anatomy and pathologic characteristics of the fetal heart (digital casts) that cannot be obtained with 2D fetal echocardiography. We propose that these modalities enhance the information provided by ultrasonographic interrogation of the fetal heart and will improve prenatal diagnosis.

Prenatal diagnosis of congenital heart disease using four-dimensional spatio-temporal image correlation (STIC) telemedicine via an Internet link: a pilot study

OBJECTIVE

To assess whether the spatio-temporal image correlation (STIC) acquisition technique can be taught to a general obstetrician by e-mail; whether STIC volume datasets can be transmitted over the Internet; and whether STIC volume datasets analyzed offline at a remote setting can be used to confirm or exclude major cardiac defects (TELE-STIC).

METHODS

This was a prospective study involving 50 pregnant women with gestational ages ranging between 20 and 36 weeks. These patients were selected by two general obstetricians (operators) working in geographically remote areas of Chile. Although both obstetricians were users of equipment capable of four-dimensional (4D) ultrasound with STIC, they lacked skill in the performance of fetal cardiac examination. A dedicated web disk was created to upload the acquired volume datasets using an Internet broadband connection. Offline analysis was performed by a single investigator experienced in fetal echocardiography (the administrator).

RESULTS

A telemedicine link via the Internet was possible in all cases. Seventy-seven volume datasets were sent to the web server. A complete cardiac examination according to set criteria was achieved by the administrator in 86% of the cases scanned by one operator and 95% of the cases scanned by the other operator. Three patients had cardiac defects confirmed postnatally, two fetuses had extracardiac anomalies and one fetus had a suspected cardiac defect unconfirmed by second-opinion TELE-STIC. There were two isolated major congenital heart defects. Both patients were given advice by e-mail and teleconference using a web camera about the likely outcome and benefits of scheduling in utero transport to a tertiary care center.

CONCLUSIONS

STIC volumes can be obtained by operators inexperienced in fetal echocardiography, transmitted via the Internet, and their analysis enables recognition of most of the structures and views necessary to assess fetal cardiac anatomy. The preliminary use of TELE-STIC allowed us to demonstrate that some intracardiac anomalies can be ruled out and others confirmed, allowing perinatal management to be tailored accordingly.

First-trimester fetal heart block and increased nuchal translucency: an indication for early fetal echocardiography

Prevalence of congenital heart disease increases with nuchal translucency (NT) thickness. First-trimester fetal bradycardia may result from heart block associated with complex congenital heart disease. We report two cases detected in the first trimester of pregnancy, in which both fetuses showed an increased nuchal translucency and bradycardia. Fetal karyotype was normal in both fetuses. First-trimester fetal echocardiography was performed and, in both cases, complex congenital heart disease was diagnosed. We discuss the added role of fetal heart rate in first-trimester ultrasound screening, in fetuses with increased nuchal translucency and normal karyotype. We stress, as well, the importance of echocardiography performed in the first trimester as a potential tool for early diagnosis in selected cases.