Early prenatal diagnosis of major cardiac anomalies in a high-risk population

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

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.

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.

First-Trimester Fetal Echocardiography: Identification of Cardiac Structures for Screening from 6 to 13 Weeks' Gestational Age

BACKGROUND

Early fetal echocardiography (FE), performed at 12 to 16 weeks' gestational age (GA), can be used to screen for fetal heart disease akin to that routinely performed in the second trimester. The efficacy of FE at earlier GAs has not been as well explored, particularly with recent advances in ultrasound technology. The aim of this study was to evaluate the efficacy of early FE in assessing fetal heart structure, and the added benefit of color Doppler (CD), from as early as 6 weeks through to 13⁺⁶ weeks' GA.

METHODS

Pregnant women were prospectively recruited for first-trimester FE. All underwent two-dimensional (2D) cardiac imaging combined with CD assessment, and all were offered second-trimester fetal echocardiographic evaluations. Fetal cardiac anatomy was assessed both in real time during FE and additionally offline by two separate reviewers.

RESULTS

Very early FE was performed in 202 pregnancies including a total of 261 fetuses, with 92% (n = 241) being reassessed at ≥18 weeks' GA. Mean GA at FE was 10⁺⁶ weeks (range, 6⁺¹ to 13⁺⁶ weeks). Transabdominal scanning was used in all cases, and transvaginal scanning was used additionally in most at <11 weeks' GA (n = 103 of 117 [88%]). There was stepwise improvement in image resolution of the fetal heart in those pregnancies that presented at later gestation for assessment. CD assisted with definition of cardiac anatomy at all GAs. A four-chambered heart could be identified in 52% of patients in the eighth week (n = 12 of 23), improving to 80% (n = 36 of 45) in the 10th week and 98% (n = 57 of 58) by the 11th week. The inferior vena cava was visualized by 2D imaging in only 4% (n = 1 of 23) in the eighth week, increasing to 13% (n = 6 of 45) by the 10th week and 80% (n = 25 of 31) by the 13th week. CD improved visualization of the inferior vena cava at earlier GAs to >80% (n = 37 of 45) from 10 weeks. Pulmonary veins were not visualized by either 2D imaging or CD until after the 11th week. Both cardiac outflow tracts could be visualized by 2D imaging in the minority from 8⁺⁰ to 10⁺⁶ weeks (n = 18 of 109 [16%]) but were imaged in most from 11⁺⁰ to 13⁺⁶ weeks (n = 114 of 144 [79%]). CD imaging improved visualization of both outflow tracts to 64% (n = 29 of 45) in the 10th week. On 2D imaging alone, both the aortic and ductal arches were seen in only 29% of patients in the 10th week (n = 13 of 45), increasing to 58% when CD was used (58% [n = 26 of 45]) and to >80% (n = 47 of 58) using CD in the 11th week.

CONCLUSIONS

Very early FE, from as early as 8 weeks, can be used to assess cardiac structures. The ability to image fetal heart structures between 6 and 8 weeks is currently nondiagnostic. The use of CD significantly increases the detection of cardiac structures on early FE. The ideal timing of complete early FE, excluding pulmonary vein assessment, appears to be after 11 weeks' GA.

Diagnostic Value of Fetal Echocardiography for Congenital Heart Disease: A Systematic Review and Meta-Analysis

Prenatal diagnosis of fetal congenital heart disease (CHD) has been shown to have a significant effect on prenatal and postnatal management and outcomes. However, the factors influencing the diagnostic accuracy and which pregnant trimester is the most adaptive for fetal heart disease remain uncertain despite of extensive researches. The aim of the present study was to evaluate the accuracy of echocardiography for detecting CHD and potential influence factors.We searched Chinese Biomedical Database (CBM), Medline, ISI Web of Knowledge, the Cochrane Library, and China National Knowledge Infrastructure (CNKI) to identify relevant studies from January 1, 1990 to August 13, 2015.Overall, the pooled sensitivity, specificity, diagnostic odds ratio, positive likelihood ratio, and negative likelihood ratio were 68.5% (95% confidence interval [CI], 66.8%-70.2%), 99.8% (95% CI, 99.7%-99.8%), 3026.9 (95% CI, 1417.9-6461.8), 659.41 (95% CI, 346.38-1255.3), and 0.246 (95% CI, 0.187-0.324) respectively (AUC = 0.9924). The pooled sensitivity of basic cardiac echocardiographic examination (BCEE), extended cardiac echocardiographic examination (ECEE), BCEE plus outflow tract view (BCEE + OTV), BCEE + OTV + 3VTV (BCEE plus outflow tract view plus three vessel and trachea view) for the prenatal diagnosis of CHD were 49.0%, 75.5%, 66.1%, and 83.7% respectively. The pooled sensitivity of the prenatal echocardiographic diagnosis of CHD during the first trimester, second trimester, the second to third trimester were 60.3%, 60.9%, and 77.4%, respectively. The pooled sensitivity of BCEE and ECEE for the prenatal diagnosis of CHD during the second to third trimester was significantly higher than that during the second trimester. The pooled sensitivity of the prenatal echocardiographic diagnosis of CHD for pregnancies with low risk, high risk, low and high risk, and unselected risk were 45.4%, 85.1%, 89.1%, and 66.2%, respectively. The sensitivity analysis was robust and risk level was significant source of heterogeneity. Deek test indicated no potential significant publication bias.Prenatal ultrasound is a powerful tool for the diagnosis of CHD; however, echocardiography has individual sensitivity for different gestation period, different levels of risk, and different echo-views.

Prenatal diagnosis and molecular cytogenetic characterization of chromosome 22q11.2 deletion syndrome associated with congenital heart defects

OBJECTIVE

To report prenatal diagnosis of 22q11.2 deletion syndrome in a pregnancy with congenital heart defects in the fetus.

CASE REPORT

A 26-year-old, primigravid woman was referred for counseling at 24 weeks of gestation because of abnormal ultrasound findings of fetal congenital heart defects. The Level II ultrasound revealed a singleton fetus with heart defects including overriding aorta, small pulmonary artery, and ventricular septal defect. Cordocentesis was performed. The DNA extracted from the cord blood was analyzed by multiplex ligation-dependent amplification (MLPA). The MLPA showed deletion in the DiGeorge syndrome (DGS) critical region of chromosome 22 low copy number repeat (LCR) 22-A∼C. Conventional cytogenetic analysis revealed a normal male karyotype. Repeated amniocentesis and cordocentesis were performed. Whole-genome array comparative genomic hybridization (aCGH) on cord blood was performed. aCGH detected a 3.07-Mb deletion at 22q11.21. Conventional cytogenetic analysis of cultured amniocytes revealed a karyotype 46,XY. Metaphase fluorescence in situ hybridization (FISH) analysis on cultured amniocytes confirmed an interstitial 22q11.2 deletion.

CONCLUSION

Prenatal ultrasound findings of congenital heart defects indicate that the fetuses are at increased risk for chromosome abnormalities. Studies for 22q11.2 deletion syndrome should be considered adjunct to conventional karyotyping. Although FISH has become a standard procedure for diagnosis of 22q11.2 deletion syndrome, MLPA can potentially diagnose a broader spectrum of abnormalities, and aCGH analysis has the advantage of refining the 22q11.2 deletion breakpoints and detecting uncharacterized chromosome rearrangements or genomic imbalances.

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.

Diagnosis and treatment of fetal cardiac disease: a scientific statement from the American Heart Association

BACKGROUND

The goal of this statement is to review available literature and to put forth a scientific statement on the current practice of fetal cardiac medicine, including the diagnosis and management of fetal cardiovascular disease.

METHODS AND RESULTS

A writing group appointed by the American Heart Association reviewed the available literature pertaining to topics relevant to fetal cardiac medicine, including the diagnosis of congenital heart disease and arrhythmias, assessment of cardiac function and the cardiovascular system, and available treatment options. The American College of Cardiology/American Heart Association classification of recommendations and level of evidence for practice guidelines were applied to the current practice of fetal cardiac medicine. Recommendations relating to the specifics of fetal diagnosis, including the timing of referral for study, indications for referral, and experience suggested for performance and interpretation of studies, are presented. The components of a fetal echocardiogram are described in detail, including descriptions of the assessment of cardiac anatomy, cardiac function, and rhythm. Complementary modalities for fetal cardiac assessment are reviewed, including the use of advanced ultrasound techniques, fetal magnetic resonance imaging, and fetal magnetocardiography and electrocardiography for rhythm assessment. Models for parental counseling and a discussion of parental stress and depression assessments are reviewed. Available fetal therapies, including medical management for arrhythmias or heart failure and closed or open intervention for diseases affecting the cardiovascular system such as twin-twin transfusion syndrome, lung masses, and vascular tumors, are highlighted. Catheter-based intervention strategies to prevent the progression of disease in utero are also discussed. Recommendations for delivery planning strategies for fetuses with congenital heart disease including models based on classification of disease severity and delivery room treatment will be highlighted. Outcome assessment is reviewed to show the benefit of prenatal diagnosis and management as they affect outcome for babies with congenital heart disease.

CONCLUSIONS

Fetal cardiac medicine has evolved considerably over the past 2 decades, predominantly in response to advances in imaging technology and innovations in therapies. The diagnosis of cardiac disease in the fetus is mostly made with ultrasound; however, new technologies, including 3- and 4-dimensional echocardiography, magnetic resonance imaging, and fetal electrocardiography and magnetocardiography, are available. Medical and interventional treatments for select diseases and strategies for delivery room care enable stabilization of high-risk fetuses and contribute to improved outcomes. This statement highlights what is currently known and recommended on the basis of evidence and experience in the rapidly advancing and highly specialized field of fetal cardiac care.

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.

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.

Prenatal diagnosis of chromosomal abnormalities in fetuses with abnormal cardiac ultrasound findings: evaluation of chromosomal microarray-based analysis

OBJECTIVES

To assess the frequency of karyotype abnormalities and chromosome 22q11.2 deletion syndrome among fetuses with abnormal cardiac ultrasound findings, and to evaluate the clinical value of chromosomal microarray-based analysis (CMA) in the study of such pregnancies.

METHODS

First, we carried out retrospective analysis of karyotype abnormalities and 22q11.2 deletion syndrome cases diagnosed between January 2009 and December 2011 in our center among fetuses with abnormal cardiac ultrasound findings (n = 276). Second, CMA was performed in 51 of the fetuses with such findings, normal karyotype and negative or no 22q11.2 deletion syndrome study, and in the only fetus with a heart defect and an apparently balanced de novo chromosomal rearrangement.

RESULTS

Out of the 276 pregnancies with abnormal cardiac ultrasound findings, karyotyping revealed a chromosomal abnormality in 44 (15.9%). Of fetuses with normal karyotype in which 22q11.2 deletion syndrome studies were performed, 6.4% (5/78) had this microdeletion syndrome. Among fetuses with abnormal cardiac findings, normal karyotype and negative or no 22q11.2 deletion syndrome study that underwent CMA, the detection rate of pathogenic copy number variants not detected by conventional cytogenetics was 2.0% (1/51), and no variants of uncertain clinical significance were found. In the fetus with a heart defect and an apparently balanced de novo chromosomal rearrangement, CMA revealed that the rearrangement was not truly balanced.

CONCLUSIONS

In the assessment of genetic abnormalities in pregnancies with abnormal cardiac ultrasound findings, the diagnostic yield may be increased by 2% if CMA is used as a complementary tool to conventional cytogenetics. Our results suggest that CMA could be a good alternative to karyotyping in these pregnancies.

Ultrasound and echocardiographic findings obtained in the second and third trimesters of gestation in fetuses with normal karyotype and increased nuchal translucency

Introduction

Numerous papers have proven that an increased nuchal translucency is connected with a raised risk of chromosomal aberrations, but few analyses are related to the further state of fetuses with a normal karyotype.

The aim of the study

The aim of the study was to estimate the risk of cardiac defects and other developmental disorders in fetuses with increased nuchal translucency and normal findings of a standard cytogenetic examination.

Methods

The authors carried out a retrospective analysis of 5183 examinations of 3376 patients who reported to the Department of Diagnosis and Prophylaxis of Congenital Malformations in the Polish Mother's Memorial Hospital in Łódź in the period from January 2008 to March 2011 for prenatal ultrasound and echocardiographic examinations. The authors analyzed the results of the examinations performed in the second and third trimesters of gestation in fetuses with an increased nuchal translucency of ≥3 mm in the first trimester and with a normal karyotype.

Results

Fifty-seven patients (1.7% of the examined group) fulfilled the criteria necessary to be included in the study. In 31 pregnant women (54%) structural defects or anomalies of the fetus were found. Cardiac anomalies were detected in 17 fetuses (29.8%). The authors detected various types of cardiac defects such as tetralogy of Fallot, ventricular septal defect, atrioventricular septal defect, transposition of the great arteries and hypoplastic left heart syndrome.

Conclusions

In more than half of the fetuses with an increased nuchal translucency (NT ≥ 3 mm) and a normal karyotype, developmental defects of various organs appeared in the further course of pregnancy: mainly heart defects that were either isolated, or accompanied other anomalies.

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.

Awareness of fetal echo in Indian scenario

Background:

Fetal echocardiography is a well established sensitive tool to diagnose congenital heart disease (CHD) in utero. One of the determinants of effective utilization of fetal echocardiography is its awareness in the general population. The present hospital based study was undertaken to assess the awareness of the need for fetal echocardiography amongst Indian parents.

Methods:

One thousand one hundred and thirty eight consecutive parents who visited the pediatric cardiology outpatient department of a tertiary care centre over a period of two months were asked to fill up a questionnaire that included their demographic data, educational status, history of CHD in children, awareness of fetal echocardiography and source of information and timing of fetal echocardiogram if performed. The data was categorized and awareness was noted in different groups.

Results:

The awareness in the study population was 2.2%. Awareness was found to be similar across the study population irrespective of the demographics and high risk status of the parents.

Conclusions:

The awareness of fetal echocardiography, an important tool in reducing the incidence of complex CHD, thereby impacting public health, is alarmingly low in the population studied. Appropriate action to increase awareness of fetal echocardiography needs to be looked into.

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.

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.

Positive predictive value of prenatal ultrasonography confirmed by post-mortem investigations

OBJECTIVE

To analyse the positive predictive value of ultrasonography based on the results of post-mortem investigations in respect of the most common malformations.

STUDY DESIGN

We processed the details of 683 cases affecting the nervous, cardiovascular, urinary and skeletal systems, and the abdominal/thoracic walls.

RESULTS

In four of the investigated groups of malformations, the proportion of sonographic diagnoses completely coinciding with the post mortem results was found to be approximately 70%, but it was found to be much lower (32%) in urinary malformations. The cumulative proportion of coinciding sonographic and post mortem diagnoses was 63%, while completely incorrect ultrasonographic diagnoses amounted to 17%.

CONCLUSIONS

Sonography is an essential method for the diagnosis of the majority of fetal malformations, but post-mortem examinations yield an indispensable quality control as well as additional information to ultrasound examinations.

Investigating 22q11.2 deletion and other chromosomal aberrations in fetuses with heart defects detected by prenatal echocardiography

Congenital heart disease (CHD) is the most common birth defect and the leading cause of mortality in the first year of life. In fetuses with a heart defect, chromosomal abnormalities are very frequent. Besides aneuploidy, 22q11.2 deletion is one of the most recognizable chromosomal abnormalities causing CHD. The frequency of this abnormality varies in nonselected populations. This study aimed to investigate the incidence of the 22q11.2 deletion and other chromosomal alterations in a Brazilian sample of fetuses with structural cardiac anomalies detected by fetal echocardiography. In a prospective study, 68 fetuses with a heart defect were evaluated. Prenatal detection of cardiac abnormalities led to identification of aneuploidy or structural chromosomal anomaly in 35.3% of these cases. None of the fetuses with apparently normal karyotypes had a 22q11.2 deletion. The heart defects most frequently associated with chromosomal abnormalities were atrioventricular septal defect (AVSD), ventricular septal defect (VSD), and tetralogy of Fallot. Autosomal trisomies 18 and 21 were the most common chromosomal abnormalities. The study results support the strong association of chromosome alterations and cardiac malformation, especially in AVSD and VSD, for which a chromosome investigation is indicated. In fetuses with an isolated conotruncal cardiopathy, fluorescence in situ hybridization (FISH) to investigate a 22q11.2 deletion is not indicated.

Abnormal first-trimester ductus venosus blood flow: a marker of cardiac defects in fetuses with normal karyotype and nuchal translucency

OBJECTIVE

To evaluate the independent contribution of ductus venosus (DV) blood flow assessment at 11-14 weeks' gestation to the prediction of congenital heart defects (CHD) in chromosomally normal fetuses, irrespective of the value of the nuchal translucency thickness (NT).

METHODS

During a 4-year period, all singleton pregnancies from 11 + 0 to 13 + 6 weeks' gestation were scanned for NT and DV blood flow in a tertiary center. Abnormal DV blood flow was defined as either absent or reversed flow during atrial contraction (AR-DV). Fetal echocardiography was performed in all cases with either NT > 99(th) percentile or AR-DV. Follow-up was assessed by postnatal examination or autopsy in cases of termination of pregnancy or perinatal death.

RESULTS

A total of 6120 pregnancies were scanned at a median gestational age of 12 weeks, and 45 cases of CHD were detected. AR-DV was found in 206 fetuses, of which 145 (70.4%) had a normal karyotype. Among fetuses with AR-DV and normal karyotype, 11 cases of CHD were diagnosed, giving a sensitivity of 24.4%, a positive predictive value of 7.6% and an odds ratio of 9.8. Increased NT (> 99(th) centile) was present in 55 of the 145 (37.9%) cases with AR-DV and normal karyotype, and in 6/11 (54.5%) of those with CHD. Thus, the group of 90 fetuses with abnormal DV blood flow and normal NT contained five cases of CHD, for a sensitivity of 11.1%, a positive predictive value of 5.5% and an odds ratio of 8.5. Right-heart anomalies were predominant in those cases with isolated AR-DV (4/5), but no specific CHD pattern was found in those with increased NT. The detection rate of CHD by the combined use of increased NT and/or AR-DV in the first trimester improved from 28.9% (13/45) to 40.0% (18/45).

CONCLUSIONS

In experienced hands, abnormal DV blood flow in the first trimester is an independent predictor of CHD and should constitute an indication for early echocardiography. In this study, the use of DV blood flow assessment increased early detection of CHD by 11% with respect to the use of NT measurement alone.

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.

Feasibility and accuracy of fetal echocardiography using four-dimensional spatiotemporal image correlation technology before 16 weeks' gestation

OBJECTIVES

To evaluate the potential value of early fetal echocardiography (EFE) by means of four-dimensional (4D) spatiotemporal image correlation (STIC) technology for either reassurance of normality or prenatal diagnosis of major congenital heart defects (CHDs).

METHODS

Sixty-nine pregnant women from 11 to 15 weeks' gestation underwent EFE. 4D-STIC volumes were acquired by the transvaginal approach for later review by two different examiners. STIC evaluation was considered complete when the four-chamber view, and the origin and double-crossing of the great arteries were identified correctly. Color Doppler imaging was used to detect either septal shunts or transvalvular regurgitation/aliasing suggesting abnormalities. STIC diagnoses were compared with those of conventional EFE. Reliability was assessed by postnatal examination, or autopsy in cases of termination of pregnancy or perinatal death.

RESULTS

The median gestational age at volume acquisition was 13 + 3 weeks. Eleven (15.9%) cases of CHD were diagnosed. A complete EFE was possible in 64 cases. We were able to provide reassurance of normality in 51 of the 53 confirmed normal hearts, with no false-positive results for major defects, although two minor defects (one ventricular septal defect (VSD) and one persistent left superior vena cava) were falsely suspected. The only false negative was a significant VSD at birth overlooked by both observers. Therefore, the total accuracy of STIC-EFE was 95.3% (61/64), with sensitivity, specificity, and positive and negative predictive values of 90.9%, 96.2%, 83.3% and 98.1%. The accuracy of conventional EFE (98.4%, 63/64) was slightly better than that of STIC, with no false-positive results recorded.

CONCLUSIONS

Offline evaluation of 4D-STIC acquired volumes of the fetal heart in the first and early second trimester of pregnancy is reliable not only for early reassurance of normal cardiac anatomy but also to diagnose most major structural heart defects.

[Common malformations in fetopathologic investigations between 1995 and 2006. Accuracy of ultrasonography confirmed by post mortem investigations]

Fetopathologic investigations are of great importance since they are aimed at assessing the risks of a malformation to recur in a mother's future pregnancy.

AIMS

The authors wished to assess and analyse the accuracy of ultrasonography based on the results of fetopathologic investigations in view of malformations of higher prevalence.

STUDY DESIGN

The authors have processed the details of 683 cases affecting the nervous, cardiovascular, urinary and skeletal systems, and the abdominal/thoracic walls detected at our department in the period of 1995-2006.

RESULTS

No significant differences could be justified as far as the major statistical parameters of maternal and gestational ages at the time of the diagnosis were concerned. There were one or another positive detail in the history in a quarter of malformations affecting the central nervous, cardiovascular and skeletal systems and in one sixth of the cases with disorders of the urinary tract as well as the abdominal/thoracic wall. Urinary tract and cardiovascular malformations were far more common among male fetuses, while moderate female dominance could be observed in malformations of the central nervous system and of the abdominal/thoracic wall. In the four investigated groups of malformations, the proportion of sonographic diagnoses completely coinciding with the post mortem results was found to be approximately or more than 70%, but it was found to be much lower (38%) in urinary malformations. Based on the full sample, the cumulative proportion of coinciding sonographic and fetopathologic diagnoses were more than 63%, while completely incorrect ultrasonographic diagnoses amounted to 18%.

CONCLUSIONS

(Even multiple) sonographic investigations are to be performed in a genetic centre if urinary tract malformation with subsequent oligohydramnion is detected. Since the associability of omphalocele and chromosome aberrations has been an established fact, and because some of the cases with omphalocele have been diagnosed as gastroschisis, it may be advisable to perform chromosome investigations in ultrasonographically diagnosed cases of gastroschisis. In cases of VSD, echocardiography should be performed in high-risk pregnancies even if ultrasonography cannot reveal any changes in the patients.

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.

Fetal echocardiography at the time of the nuchal translucency scan

OBJECTIVE

The fetal heart is not studied routinely in the first trimester because of technical and time limitations. Our aim was to assess the feasibility of performing a fetal cardiac study in pregnancies referred for nuchal translucency (NT) screening, using high-frequency linear transabdominal transducers with a specific ultrasound preset.

METHODS

A single trained operator assessed the fetal heart in pregnancies with a fetal crown-rump length (CRL) of 60-84 mm that had been referred for NT screening. A 15- or 6-MHz transabdominal linear transducer with a specific preset suitable mainly for color-flow mapping was used to confirm or refute normal cardiac anatomy rather than to establish a specific diagnosis. Fetuses having an increased risk for congenital heart disease were referred to a tertiary center for a further examination within 1 week. This group consisted of all fetuses with NT > 95(th) centile and those in which a family history or the initial heart scan increased the risk.

RESULTS

A total of 608 fetuses with a median CRL of 65 mm was examined between 2003 and 2005. A cardiac scan was performed successfully in 456 (75%) using a 15-MHz linear transducer alone, and the additional use of a 6-MHz transducer allowed diagnostic images to be obtained in a further 152. Normal cardiac anatomy was assessed confidently within 10 min in 517/608 (85%) pregnancies; in 85 (14%) a longer time was needed and six patients were rescheduled within 2 weeks because of non-diagnostic images at the initial scan. In 571/608 (94%) the risk for congenital heart disease (CHD) was not increased and the heart was considered normal at initial echocardiography; this was confirmed by later scans and at postnatal follow-up. In 37/608 (6%) fetuses the risk for CHD was increased (35 for NT > 95(th) centile and two for family history). In this group normal heart anatomy was described in 34 fetuses and confirmed by subsequent specialist echocardiography. Cardiac defects were suspected in three fetuses (all with increased NT) and confirmed by a fetal cardiologist in each case.

CONCLUSIONS

A trained operator can perform a fetal heart study during the NT screening test using transabdominal high-resolution transducers in an acceptable length of time.

Outcome of fetuses in women with pregestational diabetes mellitus

OBJECTIVE

To investigate the effects of pregestational diabetes on pregnancy outcome.

METHODS

Data of 126 women with pregestational diabetes prospectively collected and controlled in a single tertiary center. HbA(1C) levels at early pregnancy were registered. Adverse pregnancy outcome was defined as spontaneous abortion, congenital defect, stillbirth, or neonatal death.

RESULTS

There were 10 spontaneous abortions (7.9%) and 17 fetuses with congenital anomalies (13.4%), including 8 major malformations (6.3%). Compared with pregnancies with a favorable outcome, a higher HbA(1C) concentration in early pregnancy was observed in pregnancies with adverse perinatal outcome [mean (SD): 6.3 (1.6) vs. 7.2 (1.7), P=0.001]. A positive correlation between increased maternal HbA(1C) levels and the rate of fetal malformations was observed, and the group of women with poor metabolic control (early maternal HbA(1c) concentration >7%) showed a 3 to 5-fold increase in the major malformation rate. Cardiovascular and genitourinary defects accounted for 58.8% of the anomalies, and the ultrasound examinations detected seven of them (41.2%). For major malformations, the detection rate was 50% (4/8). Perinatal mortality rate was 26 per thousand (3/116). There was almost 5-fold increase in the total pregnancy loss rate in the poor control group compared with the group with fair control [22.2% vs. 5.3%, OR (95% CI): 5.1 (1.4-17.1)]. Only 11.9% of mothers used a preconception care program.

CONCLUSIONS

Pregestational diabetes mellitus is a significant risk factor for the developing fetus. Spontaneous abortions and congenital defects are more common when a poor metabolic control is present in early pregnancy. It is most important to improve access to preconception care programs for achieving a good metabolic control in early pregnancy. Ultrasound examinations have a low performance for detecting congenital defects in diabetic pregnancies.

A systematic review of the accuracy of first-trimester ultrasound examination for detecting major congenital heart disease

OBJECTIVE

To evaluate the accuracy of first-trimester ultrasound examination in detecting major congenital heart disease (CHD) using a systematic review of the literature.

METHODS

General bibliographic and specialist computerized databases along with manual searching of reference lists of primary and review articles were used to search for relevant citations. Studies were included if a first-trimester ultrasound scan was carried out to detect CHD that was subsequently verified by a reference standard. Data were extracted on study characteristics and quality, and 2 x 2 tables were constructed to calculate sensitivity and specificity.

RESULTS

Ten studies (involving 1243 patients) were suitable for inclusion. Of these, four used transabdominal ultrasonography, four used transvaginal and two used a combination. Pooled sensitivity and specificity were 85% (95% CI, 78-90%) and 99% (95% CI, 98-100%), respectively.

CONCLUSION

Ultrasound examination of the fetus in the first trimester is feasible for accurately detecting major CHD. It may be offered to women at high risk of having children with CHD.

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

OBJECTIVE

The purpose of this study was to evaluate the detection rate of early fetal echocardiography and the in utero development of congenital heart defects (CHD).

METHODS

Cases were selected from all singleton pregnancies between 1997 and 2003 in which detailed fetal 2-dimensional and color-coded Doppler echocardiography was performed in our prenatal unit between 11 weeks' and 13 weeks 6 days' gestation; 2165 cases with complete outcome parameters were analyzed.

RESULTS

During this study period, CHD were diagnosed in 46 fetuses. Between 11 and 13 weeks' gestation, 29 CHD were diagnosed (11 weeks, 9 cases; 12 weeks, 8 cases; and 13 weeks, 12 cases); 9 CHD were found in the second trimester and 2 in the third trimester. The in utero detection rate of fetal echocardiography was 86.96% (n = 40). Six additional CHD (13.04%) were detected postnatally. The spectrum of detected CHD changed with advancing gestational age and was different from the postnatal detected heart defects.

CONCLUSIONS

Early fetal echocardiography is feasible and allows the detection of most CHD. Congenital heart defects vary in appearance at different stages of pregnancy and may evolve in utero with advancing gestational age. Therefore, early fetal echocardiography should always be followed by echocardiography at mid gestation.

Early fetal echocardiography: heart biometry and visualization of cardiac structures between 10 and 15 weeks' gestation

OBJECTIVE

The purpose of this prospective cross-sectional study was to compile normative data about biometry of the fetal heart and great vessels between 10 and 15 weeks in 123 normal singleton pregnancies. Additionally, we investigated the different methods and the optimal examination time of early fetal echocardiography.

METHODS

The interrogated parameters included total heart diameter; heart area and circumference; right and left ventricular diameter; diameter, circumference, and area of the thorax; and diameter of the aorta and pulmonary trunk. Visualization of the 4-chamber view, 3-vessel view, origin and crossover of the great arteries, aortic arch, ductus arteriosus, superior and inferior venae cavae, and pulmonary veins was analyzed, and the success rates by transvaginal sonography (TVS) and transabdominal sonography (TAS) were calculated.

RESULTS

Complete evaluation of the fetal heart was impossible at 10 weeks; the total success rate increased from 45% at 11 weeks to 90% between 12 and 14 weeks and 100% at 15 weeks. Between 10 and 13 weeks, TVS was superior to TAS. At 14 weeks, both methods were similar to each other, and at 15 weeks, TAS allowed adequate visualization of all structures. Linear regression analysis showed a significant correlation between the interrogated parameters and gestational age, crown-rump length, and biparietal diameter (P < .05). The ratio of right and left ventricular diameters and the ratio of pulmonary trunk and aortic diameters were constant.

CONCLUSIONS

Early fetal heart evaluation by TVS or TAS or both is reasonable and feasible. Our normative data could be helpful for understanding the normal development of the fetal heart and great arteries and for detection of cardiac defects in early pregnancy.

Fetal echocardiography during routine first-trimester screening: a feasibility study in an unselected population

OBJECTIVE

To evaluate the feasibility of obtaining standard echocardiographic views of the fetal heart during routine first-trimester screening and construct reference ranges for cardiac biometry at 11 + 0 to 13 + 6 weeks of gestation.

METHODS

A cross-sectional study of 584 fetuses in an unselected population. Viable pregnancies with a crown-rump length (CRL) of 41-78 mm were included. Echocardiography was performed by a single obstetrician using a 5 to 7.5 MHz vaginal transducer. The course and outcome of pregnancies were recorded and information on the babies was obtained in all cases.

RESULTS

A completely satisfactory visualization of the fetal heart structures was possible in 58% (43%, 56% and 62% at 11, 12 and 13 weeks, respectively). Reference ranges were constructed from the measurements of cardiac ventricles, their outflow tracts, and cardiothoracic circumference ratio in relation to CRL.

CONCLUSION

Standard echocardiograhic views of the fetal heart can be obtained at 11 + 0 to 13 + 6 weeks of gestation using the transvaginal approach. New reference ranges were established for fetal cardiac biometry at 11 + 0 to 13 + 6 weeks of gestation.

Successful selective termination at 17 weeks' gestation in monochorionic monoamniotic twin pregnancy affected by twin-twin transfusion syndrome and discordant for hypoplastic left heart syndrome

OBJECTIVES

To report a successful selective feticide in a complicated monochorionic monoamniotic (MCMA) pregnancy.

METHODS

A case of MCMA pregnancy with severe twin-twin transfusion syndrome and discordant for hypoplastic left heart syndrome was diagnosed at 16 weeks' gestation. A complete ultrasound and fetoscopic surveillance was performed, ruling out cord entanglement and, thus, precluding the necessity of transecting the cord.

RESULTS

The selective feticide was successfully performed by bipolar coagulation of the umbilical cord of the abnormal fetus under ultrasound guidance. The survivor twin developed normally during the rest of the pregnancy and was born at term. At 6 months of age, the infant was healthy.

CONCLUSION

Selective feticide in complicated monoamniotic pregnancies can be safely performed. Cord entanglement can be confidently excluded by both ultrasound and fetoscopy, thus making the systematic transection of the umbilical cord unnecessary.

Latest advances and topics in fetal echocardiography

PURPOSE OF REVIEW

Fetal diagnosis and the supporting specialties of perinatology, neonatology, and surgery have made rapid strides in the last decade. Numerous centers are focusing on this multifaceted niche area as the medical field realizes its vast promise and potential. The authors review some of the major advancements in thought and practice in the field of fetal echocardiography while attempting to give a less detailed overview for the less involved perinatologist.

RECENT FINDINGS

First trimester fetal echocardiography has been an area of recent interest as transducer technology improves. As a result, optimum timing of first and subsequent scans and the population profile they are to be applied to have become an issue that begs consensus. Three-dimensional and four-dimensional fetal echocardiography have also received a boost for the same reasons, and both are being studied for feasibility and accuracy. Fetal tissue Doppler and spectral Doppler imaging are potential areas for exploration; the early steps have been taken. Awareness of associated ultrasound markers, such as exaggerated nuchal translucency, as clues to the presence of congenital heart disease is important, even if controversial.

SUMMARY

The issue of missed prenatal diagnosis is disturbing, especially when it arises against a background of tremendous skill and technologic support. Strategies to minimize mistakes in this critical aspect need to be agreed on by the involved teams and put in place in a multidisciplinary manner if they are to have an important impact.

The introduction of QF-PCR in prenatal diagnosis of fetal aneuploidies: time for reconsideration

Quantitative fluorescent polymerase chain reaction (QF-PCR) has recently entered the field of prenatal diagnosis to overcome the need to culture fetal cells, hence to allow rapid diagnosis of some selected chromosomal anomalies. We reviewed the studies on the accuracy of QF-PCR in detecting chromosomal anomalies at prenatal diagnosis. Overall, 22 504 samples have been analysed. The detection rate of aneuploidies of the selected chromosomes (13, 18 and 21, and X and Y) was 98.6% (95% confidence interval 97.8-99.3). QF-PCR might play a major role and be considered a valid alternative to the full karyotype. Being less expensive, and almost entirely automated, more women could undergo invasive prenatal diagnosis without significant increase in health expenditure. By using QF-PCR as a stand-alone test, the chances of non diagnosing the commonest, and the only chromosome anomalies which do increase in frequency with maternal age, are approximately one in 150 abnormal karyotypes, or one in 10-30 000 samples, based on the age distribution. These error rates might be deemed acceptable, although most structural chromosomal anomalies will be missed. At present, women are rarely informed about the full spectrum of the conditions which might be diagnosed via amniocentesis or chorionic villous sampling. Some of these anomalies might be acceptable, in view of their limited or uncertain clinical relevance, and decision analysis might, in the majority of cases, confine the full karyotype to selected women who have specific indications.

Prenatal diagnosis of aneuploidy and deletion 22q11.2 in fetuses with ultrasound detection of cardiac defects

OBJECTIVE

We report a prospective database evaluation of the occurrence of aneuploidy and deletion 22q11.2 after prenatal detection of cardiac abnormalities. To ensure the maximum inclusion, all cardiac defects were considered, with the exception of echogenic intracardiac foci.

STUDY DESIGN

Prenatal specimens with ultrasound findings of cardiac defects were identified. Physicians were provided supplementary information that described the risk of deletion 22q11.2 syndrome if the karyotype was normal. On approval, fluorescence in situ hybridization was performed to identify the 22q11.2 microdeletion.

RESULTS

Prenatal detection of cardiac abnormalities identified aneuploidy or unbalanced chromosome rearrangements in 41% of the cases that were studied. In those fetuses with normal karyotypes, 3% had the deletion 22q11.2.

CONCLUSION

These results indicate that prenatal ultrasound findings of congenital heart defects identify fetuses who are at increased risk for chromosome abnormalities. Fetuses with normal karyotypes should consider having fluorescence in situ hybridization studies for the microdeletion 22q11.2 syndrome. Chromosome and fluorescence in situ hybridization studies of family members should be recommended when a fetus is identified as having the deletion 22q11.2.

Fetal heart scanning in the first trimester

The detailed study of the fetal cardiac anatomy in the first trimester of pregnancy by means of ultrasound, transvaginally or transabdominally, is feasible and remains a safe procedure provided thermal and mechanical indices are taken into account. Optimal time for successful imaging of the four chambers and great arteries in early gestation appears to be between 13 to 14 weeks. In experienced hands, first-trimester fetal echocardiography is accurate in detecting major structural cardiac abnormalities and yields a high negative predictive value. Thus, in a clinical setting, it can be offered to families considered to be 'at risk' of cardiac defects (e.g. those with previous family history or when fetal nuchal translucency is increased) and can be a powerful tool to reassure families regarding normality of major cardiac structures and connections. However, the early detection of an important structural abnormality (chromosomally normal or not) may be associated with a high termination rate if this is an acceptable option. The high prevalence of associated chromosomal and extracardiac abnormalities for many of the high-risk families, who may benefit from this approach, cannot be ignored. Therefore, fetal heart scanning in the first trimester should be performed in conjunction with detailed first-trimester obstetric scanning.