Three cross-sectional planes for fetal color Doppler echocardiography

Live-Birth Incidence of Isolated D-Transposition of Great Arteries-The Shift in Trends Due to Early Diagnosis

This is a single tertiary population-based study conducted at a center in southwest Romania. We retrospectively compared data obtained in two periods: January 2008-December 2013 and January 2018-December 2023. The global incidence of the transposition of great arteries in terminated cases, in addition to those resulting in live-born pregnancies, remained almost constant. The live-birth incidence decreased. The median gestational age at diagnosis decreased from 29.3 gestational weeks (mean 25.4) to 13.4 weeks (mean 17.2). The second trimester and the overall detection rate in the prenatal period did not significantly change, but the increase was statistically significant in the first trimester. The proportion of terminated pregnancies in fetuses diagnosed with the transposition of great arteries significantly increased (14.28% to 75%, p = 0.019).

Efficacy of atrioventricular valve regurgitation in the first trimester for the diagnosis of atrioventricular septal defect

PURPOSE

To investigate the efficacy of atrioventricular valve regurgitation (AVVR) for predicting atrioventricular septal defect (AVSD) in the first trimester.

METHODS

We performed a prospective observational study, screening for complicated congenital heart diseases and AVVR in fetuses at 11 to 13+6 weeks of gestation by advanced dynamic flow in four-chamber view and three-vessel-trachea view.

RESULTS

43 549 fetuses at 11 to 13+6 weeks of gestation were screened by echocardiography, of which 37 cases were diagnosed with AVSD, including complete AVSD (31 cases), intermediate AVSD (3 cases) and partial AVSD (1 cases), undiagnosed intermediate AVSD (2 cases), and misdiagnosed case (2 cases). AVVR was observed in 34 cases (34/37) in the first trimester, 59. 46% (22/37) nuchal translucency greater than 95th percentile, 29. 73% (11/37) absence of nasal bone, 32. 43% (12/37) ductus venosus A wave inversion, and 40. 54% (15/37) had tricuspid regurgitation. The sensitivity of common AVVR in predicting AVSD is better than other ultrasonic indexes.

CONCLUSIONS

AVVR can be used as an ultrasonic indicator to predict AVSD in the first trimester, which is beneficial to detect AVSD.

The use of cardiac ultrasound imaging in first-trimester prenatal diagnosis of congenital heart diseases

This study aims to explore ultrasound (US) cardiac and echocardiographic features that may enable the early diagnosis of various major congenital heart diseases (CHDs). Focusing on providing useful US tools for this assessment, high resolution of US cardiac images of various CHDs, such as hypoplastic left heart syndrome, conotruncal anomalies, and univentricular heart, were evaluated. Results show that early US detection of most major CHDs is feasible during first-trimester ultrasonography cardiac evaluation. Concerns about safety issues, findings on early fetal cardiovascular hemodynamics, and cardiac lesions that can progress during the course of pregnancy were also discussed.

[Isolated right aortic arch: prenatal diagnosis characteristics, pregnancy outcomes and systematic review]

OBJECTIVE

To investigate prenatal diagnosis characteristics and pregnancy outcomes associated with isolated right aortic arch (RAA).

METHODS

A retrospective study including fetuses with isolated RAA, managed between January 2010 and February 2018. Cases were identified from the ultrasound databases of the expert pediatric cardiologists, who made the aforementioned diagnosis. All fetuses were examined by a fetal medicine imaging expert to exclude any extracardiac abnormality. A systematic review was performed to assess the prenatal diagnosis and outcomes of fetuses with isolated RAA.

RESULTS

Fifty-six fetuses were diagnosed with an isolated RAA. An isolated double aortic arch (DAA) was diagnosed in one fetus. Mean gestational age at diagnosis was 24 weeks. The sex ratio (boy/girl) was 0.89. No significant abnormality was detected in invasive tests (karyotype and FISH or microarray). Only one fetus was misdiagnosed with isolated RAA. He was the only symptomatic (stridor) newborn baby and was later diagnosed with DAA. Four studies were included in our systematic review representing 115 cases of isolated RAA. One significant chromosomal abnormality was detected: a 22q11 deletion in a newborn baby who had a postnatal finding of a soft palate cleft. There was one major obstetric complication: an intrauterine fetal demise at 41 gestational weeks.

CONCLUSION

Diagnosis of isolated RAA can be challenging. Invasive tests are to be discussed. The diagnosis of isolated RAA should not change obstetric monitoring. Nevertheless, an echocardiography should be performed systematically in these new newborn babies within their first month of life.

Can Ultrasound in Early Gestation Improve Visualization of Fetal Cardiac Structures in Obese Pregnant Women?

OBJECTIVES

To determine whether ultrasound (US) imaging of obese pregnant women in early gestation improves fetal cardiac visualization.

METHODS

We report a prospective longitudinal trial comparing late first- and early second-trimester US to traditional second-trimester US for fetal cardiac screening in maternal obesity. All study participants received US for fetal cardiac screening at a gestational age of 13 weeks to 15 weeks 6 days using a transvaginal or transabdominal approach (UST1). All patients also underwent a traditional transabdominal examination at 20 to 22 weeks (UST2). If UST2 failed to complete the cardiac visualization, a follow up examination (second UST2) was performed 2 to 4 weeks later. Imaging was considered complete if the visceral situs, 4 chambers, outflow tracts, and 3 vessels were visualized. The completion rates between UST1 and UST2 were the primary outcomes. A power analysis (85%) and sample size calculation (n = 145) were performed.

RESULTS

A total of 152 pregnancies met study criteria. Completion rates of cardiac screening were 77% for UST1 and 70% for UST2 (P = .143). This comparison reached statistical significance in patients with a body mass index of greater than 40 kg/m² (UST1 [69%] versus UST2 [38%]; P = .001). Sixty-two percent of patients with a body mass index of greater than 40 kg/m² required second UST2. The highest fetal cardiac screening completion rate was achieved when UST1 was combined with UST2 (96.1%). In 1 fetus, congenital heart disease was detected at UST1 and later confirmed.

CONCLUSIONS

This study represents the largest prospective trial assessing early-gestation US for fetal cardiac screening in the setting of maternal obesity. In obese pregnancies, the addition of early-gestation US to the 20- to 22-week US substantially improves the visualization of fetal cardiac anatomy.

Usefulness of color Doppler mode for fetal cardiac ultrasound screening in the second trimester: a study at a single perinatal center

Objectives: To evaluate the usefulness of color Doppler in fetal cardiac ultrasound screening in the second trimester.Methods: Fetuses who underwent ultrasound screening at 18-20 weeks' gestation at Showa University Hospital between 2011 and 2016 were evaluated. After delivery, neonatal congenital heart abnormalities were reviewed and compared with the antenatal ultrasound findings. Since 2014, we have added color Doppler to the routine B mode evaluation of the fetal heart. Congenital heart diseases (CHDs) found antenatally and postnatally were compared before and after protocol alternation. Medical records of all fetuses who underwent ultrasound screening at 18-20 weeks' gestation at Showa University Hospital between 2011 and 2016 were retrospectively reviewed.Results: There were 47 cases of CHDs confirmed postnatally. The detection rates of CHDs were 45.0% (9/20) in 2011-2013 and 55.6% (15/27) in 2014-2016. In 2011-2013, cases with antenatal diagnosis showed obvious abnormal findings of three-vessel view and four-chamber view with the B mode. In 2014-2016, the detection rate of isolated ventricular septal defect (VSD) was elevated from 10 to 42.9% using color Doppler.Conclusions: In this study, color Doppler improved the detection rate of CHDs. Color Doppler could give us additional information on blood flow although the canal or vessel is too small to detect morphological changes in the second trimester. It might be a useful tool for screening of CHDs with stenosis, regurgitation, and shunt that are difficult to detect by only the B mode in the second trimester.

Color and power Doppler combined with Fetal Intelligent Navigation Echocardiography (FINE) to evaluate the fetal heart

OBJECTIVE

To evaluate the performance of color and bidirectional power Doppler ultrasound combined with Fetal Intelligent Navigation Echocardiography (FINE) in examining the fetal heart.

METHODS

A prospective cohort study was conducted of fetuses in the second and third trimesters with a normal heart or with congenital heart disease (CHD). One or more spatiotemporal image correlation (STIC) volume datasets, combined with color or bidirectional power Doppler (S-flow) imaging, were acquired in the apical four-chamber view. Each successfully obtained STIC volume was evaluated by STICLoop™ to determine its appropriateness before applying the FINE method. Visualization rates for standard fetal echocardiography views using diagnostic planes and/or Virtual Intelligent Sonographer Assistance (VIS-Assistance®) were calculated for grayscale (removal of Doppler signal), color Doppler and S-flow Doppler. In four cases with CHD (one case each of tetralogy of Fallot, hypoplastic left heart and coarctation of the aorta, interrupted inferior vena cava with azygos vein continuation and asplenia, and coarctation of the aorta with tricuspid regurgitation and hydrops), the diagnostic potential of this new technology was presented.

RESULTS

A total of 169 STIC volume datasets of the normal fetal heart (color Doppler, n = 78; S-flow Doppler, n = 91) were obtained from 37 patients. Only a single STIC volume of color Doppler and/or a single volume of S-flow Doppler per patient were analyzed using FINE. Therefore, 60 STIC volumes (color Doppler, n = 27; S-flow Doppler, n = 33) comprised the final study group. Median gestational age at sonographic examination was 23 (interquartile range, 21-27.5) weeks. Color Doppler FINE generated nine fetal echocardiography views (grayscale) using (1) diagnostic planes in 73-100% of cases, (2) VIS-Assistance in 100% of cases, and (3) a combination of diagnostic planes and/or VIS-Assistance in 100% of cases. The rate of generating successfully eight fetal echocardiography views with appropriate color and S-flow Doppler information was 89-100% and 91-100% of cases, respectively, using a combination of diagnostic planes and/or VIS-Assistance. However, the success rate for the ninth echocardiography view (i.e. superior and inferior venae cavae) was 33% and 30% for color and S-flow Doppler, respectively. In all four cases of CHD, color Doppler FINE demonstrated evidence of abnormal fetal cardiac anatomy and/or hemodynamic flow.

CONCLUSIONS

The FINE method applied to STIC volumes of normal fetal hearts acquired with color or bidirectional power Doppler information can generate successfully eight to nine standard fetal echocardiography views (via grayscale, color Doppler or power Doppler) in the second and third trimesters. In cases of CHD, color Doppler FINE demonstrates successfully abnormal anatomy and/or Doppler flow characteristics. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

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.

Role of the 3-Vessel and Trachea View in Antenatal Detection of Tetralogy of Fallot

Prenatal diagnosis of tetralogy of Fallot remains less frequent compared to other major congenital heart defects. In this study, we examined how often the 3-vessel and trachea view was abnormal in a large series of prenatally diagnosed cases of tetralogy of Fallot. In addition, we compared its sensitivity to that of the traditional outflow tract views for detection of tetralogy of Fallot. We found that both views were abnormal in all fetuses with tetralogy of Fallot, showing reversed aortic-to-pulmonary valve and aortic arch isthmus-to-ductus arteriosus ratios in the outflow tract and 3-vessel and trachea views, respectively. However, as a single measured marker, the enlarged aortic arch isthmus on the 3-vessel and trachea view appears to be the most sensitive for tetralogy of Fallot.

Screening for Congenital Heart Disease

Compared with the assessment of most fetal anatomic structures, the assessment of the fetal heart during routine obstetric screening represents a diagnostic challenge for sonographers and interpreting physicians. This is due to a number of factors: the structural complexity of the heart, the rate at which it moves, the position of the fetus relative to the transducer, and variations in assessment protocols used by sonographers and physicians. The fetal heart is a relatively small and complex structure, as seen in an early second-trimester sonogram. In some forms of congenital heart disease, the abnormality may be detectable within only a relatively small fraction of the heart volume. Congenital heart disease represents a range of structural defects, a number of which have specific sonographic features that can be identified during routine assessment. Many approaches have been proposed to improve the assessment of the fetal heart, including specific still images, color Doppler, 3D imaging techniques, and cineloops.

Evaluating Spatiotemporal Image Correlation Technology as a Tool for Training Nonexpert Sonographers to Perform Examinations of the Fetal Heart

OBJECTIVES

We aimed to evaluate the use of spatiotemporal image correlation (STIC) as a tool for training nonexpert examiners to perform screening examinations of the fetal heart by acquiring and examining STIC volumes according to a standardized questionnaire based on the 5 transverse planes of the fetal heart.

METHODS

We conducted a prospective study at 2 tertiary care centers. Two sonographers without formal training in fetal echocardiography received theoretical instruction on the 5 fetal echocardiographic transverse planes, as well as STIC technology. Only women with conditions allowing 4-dimensional STIC volume acquisitions (grayscale and Doppler) were included in the study. Acquired volumes were evaluated offline according to a standardized protocol that required the trainee to mark 30 specified structures on 5 required axial planes. Volumes were then reviewed by an expert examiner for quality of acquisition and correct identification of specified structures.

RESULTS

Ninety-six of 112 pregnant women examined entered the study. Patients had singleton pregnancies between 20 and 32 weeks' gestation. After an initial learning curve of 20 examinations, trainees succeeded in identifying 97% to 98% of structures, with a highly significant degree of agreement with the expert's analysis (P < .001). A median of 2 STIC volumes for each examination was necessary for maximal structure identification. Acquisition quality scores were high (8.6-8.7 of a maximal score of 10) and were found to correlate with identification rates (P = .017).

CONCLUSIONS

After an initial learning curve and under expert guidance, STIC is an excellent tool for trainees to master extended screening examinations of the fetal heart.

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.

Is the "I-Sign" in the 3-Vessel and Trachea View a Valid Tool for Prenatal Diagnosis of D-Transposition of the Great Arteries?

Prenatal diagnosis of D-transposition of the great arteries remains less frequent compared to other major congenital heart defects. In this study, we examined how often the 3-vessel and trachea view was abnormal in a large series of prenatally diagnosed cases of D-transposition of the great arteries. We found that an abnormal 3-vessel and trachea view in the shape of an "I" ("I-sign"), which represents an anteriorly displaced aorta, was present in all fetuses with D-transposition of the great arteries when a 3-vessel and trachea view was successfully obtained. Therefore we believe that the 3-vessel and trachea view can be used to reliably detect D-transposition of the great arteries during prenatal sonography.

Systematic examination of the fetal abdominal precordial veins: a cohort study

OBJECTIVES

Examination of the fetal venous system is a necessary part of complete fetal organ scanning to confirm landmark anatomy, such as the ductus venosus and course of the umbilical veins, and, whenever cardiovascular anomalies are identified, to exclude associated anomalous development of the fetal veins. We aimed to develop a protocol for systematic examination of the fetal venous system during midtrimester targeted organ scanning.

METHODS

We included low-risk women with a singleton fetus presenting between January 2011 and June 2013 to our center for routine midtrimester (20-24 weeks) targeted organ scanning. Imaging of the venous system was added to the booked scan and comprised two-dimensional color Doppler scanning of the fetal abdomen in three discrete planes, two transverse and one longitudinal. The more caudal plane was obtained in a ventral or lateral transverse abdominal plane to image the umbilical vein, left portal vein, portal sinus, anterior right portal vein, posterior right portal vein, main portal vein and splenic vein and artery. Moving cephalad, a ventral or lateral transverse plane was obtained to image the right, middle and left hepatic veins and inferior vena cava (IVC). Finally, a longitudinal anteroposterior plane showed the umbilical vein, ductus venosus, IVC and left hepatic vein. In some cases the pulsed Doppler waveform of a given target vessel was also examined. Three-dimensional/4D ultrasound was applied as necessary, when anomalous cases were encountered.

RESULTS

We examined 1810 women. Their body mass index ranged from 19 to 40 (mean, 24.7). In 38 (2.1%) women, the target anatomy was not visualized satisfactorily owing to maternal body habitus. A T-shaped configuration of the portal system vessels was observed in 63% of cases, an X-shaped configuration in 25% and an H-shaped configuration in 12%. During the study period, 24 congenital anomalies of the precordial venous system were diagnosed: nine cases of persistent right umbilical vein, seven of agenesis of the ductus venosus, five of anomalous portal venous drainage and three of interrupted IVC with azygos continuation.

CONCLUSIONS

Examination of the fetal venous system is feasible with the application of three abdominal planes. While a venous system scan is not practicable as part of a screening-level examination, mastery of the normal anatomy is an essential part of the professional knowledge base, in order to provide ready and complete scanning of the system in cases of suspected anomalies or disordered cardiac function.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Impact of a standardized training program on midwives' ability to assess fetal heart anatomy by ultrasound

BACKGROUND

Studies of prenatal detection of congenital heart disease (CHD) in the UK, Italy, and Norway indicate that it should be possible to improve the prenatal detection rate of CHD in Sweden. These studies have shown that training programs, visualization of the outflow tracts and color-Doppler all can help to speed up and improve the detection rate and accuracy. We aimed to introduce a more accurate standardized fetal cardiac ultrasound screening protocol in Sweden.

METHODS

A novel pedagogical model for training midwives in standardized cardiac imaging was developed, a model using a think-aloud analysis during a pre- and post-course test and a subsequent group reflection. The self-estimated difficulties and knowledge gaps of two experienced and two beginner midwives were identified. A two-day course with mixed lectures, demonstrations and hands-on sessions was followed by a feedback session three months later consisting of an interview and check-up. The long-term effects were tested two years later.

RESULTS

At the post-course test the self-assessed uncertainty was lower than at the pre-course test. The qualitative evaluation showed that the color Doppler images were difficult to interpret, but the training seems to have improved their ability to use the new technique. The ability to perform the method remained at the new level at follow-up both three months and two years later.

CONCLUSIONS

Our results indicate that by implementing new imaging modalities and providing hands-on training, uncertainty can be reduced and examination time decreased, but they also show that continuous on-site training with clinical and technical back-up is important.

Screening of congenital heart disease in the second trimester of pregnancy: current knowledge and new perspectives to the clinical practice

OBJECTIVE

Congenital heart diseases are common in foetuses, with an incidence greater than six times that of chromosomal abnormalities; however, experts in cardiac anatomy have evaluated only the foetuses of pregnant women with increased risk for congenital heart disease. Over the years, it has become clear that congenital heart disease occur in foetuses of low-risk women. In the mid-1980s, a proposal to expand the assessment of cardiac anatomy was presented to obstetricians in order to improve prenatal screening. With the aim to systematise and improve the diagnosis of congenital heart disease in foetuses, the International Society of Ultrasound in Obstetrics and Gynecology established an ultrasound heart examination guideline. In this review, we have described the important features of this guideline and discussed the applications of this tool in clinical practice.

METHODS

We performed a literature search of the National Library of Medicine for publications released between 2000 and 2012; we used search terms pertinent to congenital heart disease, such as foetal echocardiography, foetal heart and cardiac screening examination.

RESULTS

The guidelines serve as a standard and help to systematise the screening for congenital heart diseases, but we think that some topics may be added to design the most appropriate screening method. However, we cannot expand the topics to be evaluated in this examination without good training of sonographers who undergo this screening.

CONCLUSION

Although the screening standardisation is a good tool to be used in day-to-day practice, the increment of aortic and ductal archs and colour Doppler to heart screening could be useful to detect further cardiac defects.

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.

Prenatal ultrasonography and Doppler sonography for the clinical investigation of isolated ventricular septal defects in a late second-trimester population

Background

The purpose of this study was to evaluate the efficacy of prenatal ultrasonography and Doppler sonography in detecting isolated ventricular septal defects (VSDs) in a late-second-trimester population.

Methods

Fetal echocardiography, Doppler ultrasound, and biometry were used to evaluate 2,661 singleton fetuses (1,381 male fetuses and 1,280 female fetuses) between 1 August 2006 and 31 May 2010. The efficacy of each fetal biometry, Doppler ultrasound, and nasal bone length (NBL) measurement was evaluated in all of the fetuses. A standard fetal echocardiographic evaluation, including two-dimensional gray-scale imaging and color and Doppler color flow mapping, was performed on all fetuses.

Results

We detected isolated VSDs in 124 of the 2,661 singleton fetuses between 19 and 24 weeks of gestation. The prevalence of isolated VSDs in the study population was 4.66%. A multiple logistic regression analysis indicated that short fetal NBL (odds ratio = 0.691, 95% confidence interval: 0.551 to 0.868) and the pulsatility index (PI) of the umbilical artery (odds ratio = 8.095, 95% confidence interval: 4.309 to 15.207) and of the middle cerebral artery (odds ratio = 0.254, 95% confidence interval: 0.120 to 0.538) are significantly associated with isolated VSDs.

Conclusion

Late-second-trimester fetal NBL, umbilical artery PI, and middle cerebral artery PI are useful parameters for detecting isolated VSDs, and can be used to estimate the a priori risk of VSDs in women at high risk and at low risk of isolated VSDs.

The fetal three-vessel and tracheal view revisited

The routine use of four-chamber screening of the fetal heart was pioneered in the early 1980s and has been shown to detect reliably mainly univentricular hearts in the fetus. Many conotruncal anomalies and ductal-dependent lesions may, however, not be detected with the four-chamber view alone and additional planes are needed. The three-vessel and tracheal (3VT) view is a transverse plane in the upper mediastinum demonstrating simultaneously the course and the connection of both the aortic and ductal arches, their relationship to the trachea and the visualization of the superior vena cava. The purpose of the article is to review the two-dimensional anatomy of this plane and the contribution of colour Doppler and to present a checklist to be achieved on screening ultrasound. Typical suspicions include the detection of abnormal vessel number, abnormal vessel size, abnormal course and alignment and abnormal colour Doppler pattern. Anomalies such as pulmonary and aortic stenosis and atresia, aortic coarctation, interrupted arch, tetralogy of Fallot, common arterial trunk, transposition of the great arteries, right aortic arch, double aortic arch, aberrant right subclavian artery, left superior vena cava are some of the anomalies showing an abnormal 3VT image. Recent studies on the comprehensive evaluation of the 3VT view and adjacent planes have shown the potential of visualizing the thymus and the left brachiocephalic vein during fetal echocardiography and in detecting additional rare conditions. National and international societies are increasingly recommending the use of this plane during routine ultrasound in order to improve prenatal detection rates of critical cardiac defects.

Fetal Intelligent Navigation Echocardiography (FINE): a novel method for rapid, simple, and automatic examination of the fetal heart

OBJECTIVE

To describe a novel method (Fetal Intelligent Navigation Echocardiography (FINE)) for visualization of standard fetal echocardiography views from volume datasets obtained with spatiotemporal image correlation (STIC) and application of 'intelligent navigation' technology.

METHODS

We developed a method to: 1) demonstrate nine cardiac diagnostic planes; and 2) spontaneously navigate the anatomy surrounding each of the nine cardiac diagnostic planes (Virtual Intelligent Sonographer Assistance (VIS-Assistance®)). The method consists of marking seven anatomical structures of the fetal heart. The following echocardiography views are then automatically generated: 1) four chamber; 2) five chamber; 3) left ventricular outflow tract; 4) short-axis view of great vessels/right ventricular outflow tract; 5) three vessels and trachea; 6) abdomen/stomach; 7) ductal arch; 8) aortic arch; and 9) superior and inferior vena cava. The FINE method was tested in a separate set of 50 STIC volumes of normal hearts (18.6-37.2 weeks of gestation), and visualization rates for fetal echocardiography views using diagnostic planes and/or VIS-Assistance® were calculated. To examine the feasibility of identifying abnormal cardiac anatomy, we tested the method in four cases with proven congenital heart defects (coarctation of aorta, tetralogy of Fallot, transposition of great vessels and pulmonary atresia with intact ventricular septum).

RESULTS

In normal cases, the FINE method was able to generate nine fetal echocardiography views using: 1) diagnostic planes in 78-100% of cases; 2) VIS-Assistance® in 98-100% of cases; and 3) a combination of diagnostic planes and/or VIS-Assistance® in 98-100% of cases. In all four abnormal cases, the FINE method demonstrated evidence of abnormal fetal cardiac anatomy.

CONCLUSIONS

The FINE method can be used to visualize nine standard fetal echocardiography views in normal hearts by applying 'intelligent navigation' technology to STIC volume datasets. This method can simplify examination of the fetal heart and reduce operator dependency. The observation of abnormal echocardiography views in the diagnostic planes and/or VIS-Assistance® should raise the index of suspicion for congenital heart disease.

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.

Three-dimensional sonography in the prenatal diagnosis of aortic arch abnormalities

PURPOSE

To assess the added value of 3-dimensional (3D) echocardiography with spatiotemporal image correlation (STIC) in the diagnosis of aortic arch abnormalities in fetuses with isolated abnormal upper thoracic 3-vessel view (3VV).

METHOD

A total of 3,420 women underwent a targeted anatomic survey at 18-22 weeks' gestation in a 1-year period. An isolated abnormal upper thoracic 3VV detected on 2-dimensional (2D) imaging was followed up by conventional 2D echocardiography and 3D fetal echocardiography with STIC. Offline reconstruction by a second operator blinded to the suspected diagnosis was performed. Neonatal echocardiography and MRI with 3D reconstruction were performed to verify the prenatal diagnosis.

RESULT

Of the 3,420 patients referred, 4 had an isolated abnormal 3VV (0.09%). A right-sided aortic arch (RAA, n = 3) and double aortic arch (DAA, n = 1) were suspected. In all aortic arch abnormalities, 3D fetal echocardiography and STIC correctly identified RAA with aberrant left subclavian artery in 3 cases and DAA in 1 case with a degree of definition that was equal to the confirmatory postnatal echocardiography and 3D MRI.

CONCLUSION

Although the 2D upper 3VV is a powerful screening tool for isolated aortic arch abnormalities, 3D fetal echocardiography with STIC allows an accurate prenatal characterization of the abnormality to a degree that is typically attainable only by post partum imaging.

Prenatal diagnosis and outcome of isolated vascular rings

The purpose of this study was to describe our experience in the ultrasound visualization and management of prenatally diagnosed isolated vascular rings. From January 2002 to December 2007, a total of 19 fetuses had a sonographic diagnosis of isolated vascular rings in 2 reference centers at a mean gestational age of 23 weeks. There were 8 cases of left aortic arch with aberrant right subclavian artery, 5 cases of double aortic arch, and 6 cases of right aortic arch with aberrant left subclavian artery. Two fetuses had associated trisomy 21 and 1 had a 22q11 microdeletion. Parents chose to terminate the pregnancy in all cases. Four patients successfully underwent surgical correction, and in 1 patient, tracheoplasty was also performed. In conclusion, isolated vascular rings can be accurately diagnosed prenatally by using the "3-vessel and trachea view" and "supra-aortic-branch view" that allow detection of vascular structures running around the trachea. Karyotyping and prenatal testing for 22q11 microdeletions should be offered to all parents. Affected children should undergo surgical correction as soon as symptoms of tracheal compression appear, avoiding tracheomalacia. Associated congenital tracheal stenosis should be excluded before surgery.

Cardiac screening by STIC: can sonologists performing the 20-week anomaly scan pick up outflow tract abnormalities by scrolling the A-plane of STIC volumes?

OBJECTIVE

To assess whether medically qualified sonologists with low-to-intermediate scanning experience are able to detect major abnormalities of the outflow tracts by reviewing the A-plane of cardiac volume datasets acquired with spatiotemporal image correlation (STIC).

METHODS

Fourteen sonologists of low-to-intermediate scanning experience were recruited among residents and colleagues involved in the screening ultrasound clinic at our referral center. Basic criteria for selection were: ability to perform the 20-week anomaly scan and to assess the four-chamber view, inability to perform extended cardiac screening (outflows); willingness to participate in the study. These sonologists attended a 2-hour lesson on: a) how the outflow tract views can be abnormal, and b) how to use a laptop and the dedicated software to review cardiac volumes in the A-plane only. After this briefing, each of them, independently, reviewed 26 preselected volumes at a workstation (from 16 normal fetuses and 10 with outflow tract abnormalities), without knowing how many of them were normal. After reviewing each volume, the sonologist was asked to define the outflow tract views as normal or abnormal and, if willing, to hypothesize the anomaly. The sequence of cases was changed for each participant. The time allotted for review of the volumes was 1 hour (about 2 min per case).

RESULTS

Of the 364 diagnoses from review of the volumes, 116 (31.9%) were true positives, 195 (53.6%) were true negatives, 29 (8.0%) were false positives and 24 (6.6%) were false negatives. The sensitivity, specificity and positive and negative predictive values were 83%, 87%, 80% and 89%, respectively. Individual diagnostic accuracy ranged from 66 to 100% (median, 85.5%) and individual detection rate from 50 to 100% (median, 85%). The detection rate per single congenital heart disease ranged from 50% (for TGA with intact ventricular septum) to 100% (for DORV, DORV with pulmonary atresia and TGA with ventricular septal defect). There was no correlation between detection rate and alignment of the four-chamber view with the ultrasound beam (apical vs. transverse).

CONCLUSIONS

In this preliminary study, we have demonstrated that sonologists with low-to-intermediate experience of anomaly ultrasound screening in the second trimester and no experience of insonating the outflow tracts were able to identify outflow tract abnormalities by reviewing the A-plane of cardiac volume datasets, after detailed briefing.

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.

Four chamber view plus three-vessel and trachea view for a complete evaluation of the fetal heart during the second trimester

OBJECTIVE

To test the efficacy of a recently introduced ultrasonic scanning plane (three vessel and trachea view -3VTV- plus color flow mapping -3VTVC) on a low-risk population for detection of congenital heart disease (CHD).

PATIENTS AND SETTING

Antenatal clinic dealing with local low-risk population. All antenatal patients having a second trimester scan in a 1 year period. All patients had a 3VT plus 3VTC views added to routine four chamber view. Postnatal examinations were performed according to standard hospital protocol.

RESULTS

2847 patients were examined. The plane was achievable in all 23 fetuses with CHD detected, three false negative (aortic coarctation) and two false positive. Sensitivity of the examination was 88.5%, as high as more sophisticated and difficult targeted cardiac scanning. The extra time necessary to perform the test was minimal.

CONCLUSION

3VTV and 3VTCV were satisfactory used as imaging planes in a busy antenatal clinic in a low-risk population. They could be easily added to the four chamber view as routine screening for CHD and increase the detection rate to 90%.

Right aortic arch detected in fetal life

OBJECTIVE

To evaluate the prenatal distribution, associated conditions and outcome of the different types of right aortic arch (RAA) detected in fetal life.

METHODS

This was a retrospective review of all cases of RAA detected prenatally between 1998 and 2005 in two tertiary referral centers.

RESULTS

In the study period 71 cases of RAA were detected; 26 (37%) had RAA with aberrant left subclavian artery, 23 (32%) had RAA with mirror-image branching, 20 (28%) had RAA of unknown type and two (3%) had double aortic arch. While 20/26 cases with RAA and aberrant left subclavian artery were isolated findings, all 23 cases with RAA and mirror-image branching were associated with cardiac defects, namely tetralogy of Fallot (43%) or pulmonary atresia with ventricular septal defect (22%). Of the 20 cases with RAA, 19 of unknown type were associated with heterotaxy syndromes and had additional cardiac malformations and ambiguities of the situs. The two cases with DAA were isolated findings. Seven cases in our series (10%) had a microdeletion 22q11 and these were significantly associated with extracardiac malformations. The outcome in our series depended solely on the associated cardiac and extracardiac malformations, with the exception of one infant with isolated DAA, in whom a surgical correction was warranted.

CONCLUSIONS

RAA detected in fetal life is associated frequently with other cardiac/non-cardiac malformations, heterotaxy syndromes and microdeletions 22q11. The associated conditions vary depending on the branching type of the brachiocephalic vessels and the presence of extracardiac malformations.

Prenatal screening for congenital heart disease with four-chamber and outflow-tract views: a multicenter study

OBJECTIVE

Congenital heart diseases (CHD) are the most common congenital anomalies, and most cases occur in the low-risk population. Prenatal ultrasound screening based on visualization of the four-chamber view has had disappointing results in detecting these anomalies thus far. The aim of this study was to evaluate the diagnostic accuracy of ultrasound screening based on the combination of the four-chamber and outflow-tract views.

METHODS

We conducted a multicenter prospective observational study in 15 obstetric units in the Piedmont Region, Italy. All operators received specific training. Data were recorded regarding visualization of the four-chamber view and the outflow tracts at each routine scan in pregnancies without any risk factor. When an anomaly was suspected, the patient was sent to the referral center. We obtained the follow-up data of the newborns until discharge from hospital and calculated the diagnostic accuracy of the test.

RESULTS

9074 ultrasound scans were performed on 7041 women and complete follow-up information was available for 6368 of them. Fifty-eight cases of CHD were observed at birth or postmortem (prevalence 9.1 per thousand); 38 of them were diagnosed in utero. The sensitivity of the test was 65.5%, the specificity 99.7%, the positive predictive value 70.4% and the negative predictive value 99.7%. The sensitivity of the four-chamber view alone was 60.3%.

CONCLUSIONS

The sensitivity was significantly higher than that in a similar study performed in 1997 in the same setting. This improvement can be attributed in part to extension of the examination to the outflow-tract view, but also to technological developments and better training of the operators.

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.

Changes in pulmonary venous Doppler parameters in fetal cardiac defects

OBJECTIVES

Recent observations in pediatric cardiological studies have prompted discussion on the possible role of intrauterine pulmonary venous changes in neonatal and postoperative outcome of infants with congenital heart defects. This study analyzes changes of Doppler blood flow velocity waveforms in the pulmonary veins of fetuses with different cardiac defects.

METHODS

Eighty fetuses (mean gestational age, 27 weeks) with prenatally diagnosed cardiac defects were classified into one of five groups: obstructed left atrium, other left ventricular outflow tract obstruction, right ventricular outflow tract obstruction, miscellaneous cardiac defects and total anomalous pulmonary venous drainage. Doppler examination of the pulmonary veins was performed and the time velocity integral (TVI), end-diastolic (A) velocity, and pulsatility index for veins (PIV) were compared with reference ranges.

RESULTS

Fetuses with infradiaphragmatic total anomalous pulmonary venous drainage showed a continuous Doppler flow pattern instead of the typical pulsatile waveform pattern. In fetuses with obstructed left atrium and restrictive foramen ovale, a reversed A-velocity and increased PIV were found. In five of the eight fetuses with left outflow tract obstruction but patent mitral valve, PIV was increased. In the other groups there were no obvious changes in Doppler parameters.

CONCLUSIONS

We suggest routine examination of the pulmonary veins with pulsed Doppler ultrasound in every fetus with a prenatally diagnosed heart defect. Such Doppler parameters could be used in future as cut-offs for the recently reported in-utero atrial septostomy to decompress an obstructed left atrium.

Prenatal detection of heart defects in a non-selected population of 30,149 fetuses--detection rates and outcome

OBJECTIVES

To evaluate the detection rate of congenital heart defects (CHD) in a non-selected population and to follow outcome after diagnosis.

METHODS

All 30,149 fetuses/newborns that were scheduled to deliver at our hospital between February 1991 and December 2001 were registered prospectively. Of these, 29,460 (98%) fetuses had a prenatal ultrasound scan at our center. The routine fetal examination at approximately 18 weeks' gestation included the four-chamber view and the great arteries of the fetal heart. The follow-up period was 2-13 years.

RESULTS

Of 97 major CHDs, 55 (57%) were detected prenatally, 16% (9/55) prior to, 66% (36/55) at and 18% (10/55) after the routine scan. Forty-four percent (19/43) of the isolated CHDs, 67% (36/54) of those with associated malformations and 48% (11/23) of the isolated ductal-dependent CHDs were detected. Thirty-eight percent (37/97) had an abnormal karyotype. Of the 55 major CHDs detected, 44% (24) of the pregnancies with lethal/serious fetal malformations were terminated, 15% (8) died in utero, 42% (23) were born alive and 27% (15) were still alive after 2 years. Of the 42 CHDs detected postnatally, 2% (1) were terminated for other reasons, 98% (41) were born alive and 81% (34) were still alive after 2 years.

CONCLUSIONS

Prenatal detection of CHD is still a challenge, with a 57% detection rate only. Isolated defects are detected less frequently. The overall outcome suggests that the most severe defects are detected with the present screening setting; only 27% of the babies with major CHDs detected were still alive after 2 years. Data from long-term follow-up will be of importance for the counseling process.

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.

Cardiovascular phenotyping of fetal mice by noninvasive high-frequency ultrasound facilitates recovery of ENU-induced mutations causing congenital cardiac and extracardiac defects

As part of a large-scale noninvasive fetal ultrasound screen to recover ethylnitrosourea (ENU)-induced mutations causing congenital heart defects in mice, we established a high-throughput ultrasound scanning strategy for interrogating fetal mice in utero utilizing three orthogonal imaging planes defined by the fetus’ vertebral column and body axes, structures readily seen by ultrasound. This contrasts with the difficulty of acquiring clinical ultrasound imaging planes which are defined by the fetal heart. By use of the three orthogonal imaging planes for two-dimensional (2D) imaging together with color flow, spectral Doppler, and M-mode imaging, all of the major elements of the heart can be evaluated. In this manner, 10,091 ENU-mutagenized mouse fetuses were ultrasound scanned between embryonic days 12.5 and 19.5, with 324 fetuses found to die prenatally and 425 exhibiting cardiovascular defects. Further analysis by necropsy and histology showed heart defects that included conotruncal anomalies, obstructive lesions, and shunt lesions as well as other complex heart diseases. Ultrasound imaging also identified craniofacial/head defects and body wall closure defects, which necropsy revealed as encephalocele, holoprosencephaly, omphalocele, or gastroschisis. Genome scanning mapped one ENU-induced mutation associated with persistence truncus arteriosus and holoprosencephaly to mouse chromosome 2, while another mutation associated with cardiac defects and omphalocele was mapped to mouse chromosome 17. These studies show the efficacy of this novel ultrasound scanning strategy for noninvasive ultrasound phenotyping to facilitate the recovery of ENU-induced mutations causing congenital heart defects and other extracardiac anomalies.