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

Fetal cardiac screening: 1st trimester and beyond

Congenital heart defects (CHD) are the most common birth defect and a leading cause of infant morbidity and mortality. CHD often occurs in low-risk pregnant patients, which underscores the importance of routine fetal cardiac screening at the time of the 2nd trimester ultrasound. Prenatal diagnosis of CHD is important for counseling and decision-making, focused diagnostic testing, and optimal perinatal and delivery management. As a result, prenatal diagnosis has led to improved neonatal and infant outcomes. Updated fetal cardiac screening guidelines, coupled with technological advancements and educational efforts, have resulted in increased prenatal detection of CHD in both low- and high-risk populations. However, room for improvement remains. In recent years, fetal cardiac screening for specific high-risk populations has started in the 1st trimester, which is a trend that is likely to expand over time. This review discusses fetal cardiac screening throughout pregnancy.

Cardiac Axis in Early Gestation and Congenital Heart Disease

Congenital heart defects represent the most common structural anomalies observed in the fetal population, and they are often associated with significant morbidity and mortality. The fetal cardiac axis, which indicates the orientation of the heart in relation to the chest wall, is formed by the angle between the anteroposterior axis of the chest and the interventricular septum of the heart. Studies conducted during the first trimester have demonstrated promising outcomes with respect to the applicability of cardiac axis measurement in fetuses with congenital heart defects as well as fetuses with extracardiac and chromosomal anomalies, which may result in improved health outcomes and reduced healthcare costs. The main aim of this review article was to highlight the cardiac axis as a reliable and powerful marker for the detection of congenital heart defects during early gestation, including defects that would otherwise remain undetectable through the conventional four-chamber view.

Use of artificial intelligence in obstetrics: not quite ready for prime time

Artificial intelligence is finding several applications in healthcare settings. This study aimed to report evidence on the effectiveness of artificial intelligence application in obstetrics. Through a narrative review of literature, we described artificial intelligence use in different obstetrical areas as follows: prenatal diagnosis, fetal heart monitoring, prediction and management of pregnancy-related complications (preeclampsia, preterm birth, gestational diabetes mellitus, and placenta accreta spectrum), and labor. Artificial intelligence seems to be a promising tool to help clinicians in daily clinical activity. The main advantages that emerged from this review are related to the reduction of inter- and intraoperator variability, time reduction of procedures, and improvement of overall diagnostic performance. However, nowadays, the diffusion of these systems in routine clinical practice raises several issues. Reported evidence is still very limited, and further studies are needed to confirm the clinical applicability of artificial intelligence. Moreover, better training of clinicians designed to use these systems should be ensured, and evidence-based guidelines regarding this topic should be produced to enhance the strengths of artificial systems and minimize their limits.

Cardiovascular Complications of Down Syndrome: Scoping Review and Expert Consensus

Cardiovascular disease is a leading cause of morbidity and mortality in individuals with Down syndrome. Congenital heart disease is the most common cardiovascular condition in this group, present in up to 50% of people with Down syndrome and contributing to poor outcomes. Additional factors contributing to cardiovascular outcomes include pulmonary hypertension; coexistent pulmonary, endocrine, and metabolic diseases; and risk factors for atherosclerotic disease. Moreover, disparities in the cardiovascular care of people with Down syndrome compared with the general population, which vary across different geographies and health care systems, further contribute to cardiovascular mortality; this issue is often overlooked by the wider medical community. This review focuses on the diagnosis, prevalence, and management of cardiovascular disease encountered in people with Down syndrome and summarizes available evidence in 10 key areas relating to Down syndrome and cardiac disease, from prenatal diagnosis to disparities in care in areas of differing resource availability. All specialists and nonspecialist clinicians providing care for people with Down syndrome should be aware of best clinical practice in all aspects of care of this distinct population.

Cardiovascular Anomalies among 1005 Fetuses Referred to Invasive Prenatal Testing-A Comprehensive Cohort Study of Associated Chromosomal Aberrations

This retrospective cohort study comprehensively evaluates cardiovascular anomalies (CVAs) and associated extracardiac structural malformations (ECMs) among 1005 fetuses undergoing invasive prenatal testing at a single tertiary Polish center in the context of chromosomal aberrations detected in them by array comparative genomic hybridization (aCGH) and G-band karyotyping. The results of our study show that CVAs are among the most common malformations detected in fetuses undergoing invasive prenatal testing, as they affected 20% of all cases seen in our department. Septal defects predominated among fetuses with numerical aberrations, while conotruncal defects were the most common findings among fetuses with pathogenic copy number variants (CNVs). In 61% of cases, CVAs were associated with ECMs (the diagnosis was confirmed postnatally or in cases of pregnancy termination by means of autopsy). The most common ECMs were anomalies of the face and neck, followed by skeletal defects. In total, pathogenic chromosomal aberrations were found in 47.5% of CVAs cases, including 38.6% with numerical chromosomal aberrations. Pathogenic CNVs accounted for 14.5% of cases with CVAs and normal karyotype. Thus, our study highlights the importance of assessing the anatomy of the fetus, and of the genetic testing (preferably aCGH) that should be offered in all CVA and ECM cases.

Evaluation of Fetal Cardiac Size and Shape: A New Screening Tool to Identify Fetuses at Risk for Tetralogy of Fallot

OBJECTIVE

Prenatal detection rates for tetralogy of Fallot (TOF) vary between 23 and 85.7%, in part because of the absence of significant structural abnormalities of the 4-chamber view (4CV), as well as the relative difficulty in detection of abnormalities during the screening examination of the outflow tracts. The purpose of this study was to evaluate whether the 4CV and ventricles in fetuses with TOF may be characterized by abnormalities of size and shape of these structures.

METHODS

This study retrospectively evaluated 44 fetuses with the postnatal diagnosis of TOF. Measurements were made from the 4CV (end-diastolic length, width, area, global sphericity index, and cardiac axis) and the right (RV) and left (LV) ventricles (area, length, 24-segment transverse widths, sphericity index, and RV/LV ratios). Logistic regression analysis was performed to identify variables that might separate fetuses with TOF from normal controls.

RESULTS

The mean gestational age at the time of the last examination prior to delivery was 28 weeks 5 days (SD 4 weeks, 4 days). The mean z-scores were significantly lower in fetuses with TOF for the 4CV and RV and LV measurements of size and shape. Logistic regression analysis identified simple linear measurements of the 4CV, RV, and LV that had a sensitivity of 90.9 and specificity of 98.5% that outperformed the 4CV cardiac axis (sensitivity of 22.7%) as a screening tool for TOF.

CONCLUSIONS

Measurements of the 4CV, RV, and LV can be used as an adjunct to the outflow tract screening examination to identify fetuses with TOF.

Prenatal diagnosis of congenital heart defects: echocardiography

Congenital heart defects (CHD) are the most common congenital anomaly, and the majority can be diagnosed during prenatal life. Prenatal detection rates remain highly variable, as most CHD occur in low risk pregnancies and therefore depend on the maternal obstetric provider to recognize fetal cardiac abnormality on obstetric screening anatomic ultrasound. Fetuses with abnormal findings on obstetric screening anatomic ultrasound and/or risk factors for cardiac disease should be referred for evaluation with fetal echocardiography. Fetal echocardiography should be performed by specialized sonographers and interpreted by physicians with knowledge of evolving fetal cardiac anatomy and physiology throughout gestation. A fetal echocardiography examination, which can be done from the late first trimester onward, utilizes a standardized and systemic approach to diagnose fetuses with CHD or other forms of primary or secondary cardiac disease. The field of fetal cardiology has advanced past the accurate prenatal diagnosis of simple and complex CHD, as fetal echocardiography enables understanding of dynamic fetal cardiac physiology and consideration of potential fetal/neonatal treatment. The greatest impact of fetal echocardiography remains identification of critical CHD before birth to allow immediate cardiac management after delivery to decrease neonatal morbidity and mortality. Analyzing the severity of abnormal cardiac physiology in various forms of CHD before birth allows the fetal cardiologist to prognosticate effects on the developing fetus, predict risk of postnatal hemodynamic instability, guide delivery planning through multidisciplinary collaboration, and anticipate how the disease will impact the neonate after delivery.

Impact of Socioeconomic Status, Race and Ethnicity, and Geography on Prenatal Detection of Hypoplastic Left Heart Syndrome and Transposition of the Great Arteries

BACKGROUND

Prenatal detection (PND) has benefits for infants with hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA), but associations between sociodemographic and geographic factors with PND have not been sufficiently explored. This study evaluated whether socioeconomic quartile (SEQ), public insurance, race and ethnicity, rural residence, and distance of residence (distance and driving time from a cardiac surgical center) are associated with the PND or timing of PND, with a secondary aim to analyze differences between the United States and Canada.

METHODS

In this retrospective cohort study, fetuses and infants <2 months of age with HLHS or TGA admitted between 2012 and 2016 to participating Fetal Heart Society Research Collaborative institutions in the United States and Canada were included. SEQ, rural residence, and distance of residence were derived using maternal census tract from the maternal address at first visit. Subjects were assigned a SEQ z score using the neighborhood summary score or Canadian Chan index and separated into quartiles. Insurance type and self-reported race and ethnicity were obtained from medical charts. We evaluated associations among SEQ, insurance type, race and ethnicity, rural residence, and distance of residence with PND of HLHS and TGA (aggregate and individually) using bivariate analysis with adjusted associations for confounding variables and cluster analysis for centers.

RESULTS

Data on 1862 subjects (HLHS: n=1171, 92% PND; TGA: n=691, 58% PND) were submitted by 21 centers (19 in the United States). In the United States, lower SEQ was associated with lower PND in HLHS and TGA, with the strongest association in the lower SEQ of pregnancies with fetal TGA (quartile 1, 0.78 [95% CI, 0.64-0.85], quartile 2, 0.77 [95% CI, 0.64-0.93], quartile 3, 0.83 [95% CI, 0.69-1.00], quartile 4, reference). Hispanic ethnicity (relative risk, 0.85 [95% CI, 0.72-0.99]) and rural residence (relative risk, 0.78 [95% CI, 0.64-0.95]) were also associated with lower PND in TGA. Lower SEQ was associated with later PND overall; in the United States, rural residence and public insurance were also associated with later PND.

CONCLUSIONS

We demonstrate that lower SEQ, Hispanic ethnicity, and rural residence are associated with decreased PND for TGA, with lower SEQ also being associated with decreased PND for HLHS. Future work to increase PND should be considered in these specific populations.

Reliability of Sonography-based Volume Computer Aided Diagnosis in the Normal Fetal Heart

OBJECTIVES

To explore the inter- and intra-observer reliability of Sonography-based Volume Computer Aided Diagnosis (SonoVCAD) in the display of 8 diagnostic planes of fetal echocardiography and to evaluate its efficiency.

METHODS

Three-dimensional volume data sets of the 56 normal singleton fetuses were acquired from a 4-chamber view by using a volume probe. After processing the data sets by using SonoVCAD, 8 cardiac diagnostic planes were displayed automatically. Three doctors with different experiences of performing fetal echocardiography evaluated each diagnostic plane and the success rates of 8 diagnostic planes were calculated. Inter-observer and intra-observer reliabilities were estimated by Cohen's kappa statistics.

RESULTS

A total of 276 volume data sets acquired from the 56 normal fetuses were used for SonoVCAD analysis and display. The success rate of each diagnostic section was more than 90%, ranging from 90.6% to 99.6%. Among 276 volumes, 81.5% (225/276) of volumes were able to generate all 8 diagnostic views successfully. Moderate to substantial agreement (kappa, 0.509-0.794) was found between 2 less experienced operators. Moderate to near-perfect agreement (kappa, 0.439-0.933) was found between an expert and 2 less experienced sonographers. Intra-observer reliability was substantial to near-perfect (kappa, 0.602-0.903). The efficiency of SonoVCAD was assessed. The expert spent less time than 2 less experienced examiners (P < 0.001) but no significant difference was found between 2 less experienced examiners (P = 0.176). Besides, SonoVCAD consumed significantly less time than 2-dimensional ultrasound (P < 0.001).

CONCLUSIONS

SonoVCAD can significantly improve the success rates of 8 diagnostic planes in fetal echocardiography with low operator dependency, good reproducibility and high efficiency.

Feasibility of Semiautomatic Fetal Intelligent Navigation Echocardiography for Different Fetal Spine Positions: A Matter of "Time"?

OBJECTIVES

We investigated the feasibility of a semiautomatic approach for assessments of the fetal heart (fetal intelligent navigation echocardiography [FINE]) in cases of optimal and unfavorable fetal spine positions.

METHODS

In this study, a total of 1693 spatiotemporal image correlation volumes of first-, second-, and third-trimester fetuses were evaluated by experts using the FINE approach. The data were analyzed regarding proper reconstruction of the diagnostic cardiac planes depending on the fetal spine position.

RESULTS

A total of 1531 volumes were included. The volumes were divided into 4 groups depending on the fetal spine position: 5-7 o'clock, 4 + 8 o'clock, 3 + 9 o'clock, and 2 + 10 o'clock. In total, 93.2% of the diagnostic planes were displayed properly. Between 5 and 7 o'clock, 94.9% of the diagnostic planes were displayed properly. The correct depiction rates in the other groups were 92.4% (4 + 8 o'clock; n = 538; P = 0.0027), 88.3% (3 + 9 o'clock; n = 156; P < .0001), and 87.3% (2 + 10 o'clock; n = 41; P = .0139). In total, the highest dropout rates were found in the sagittal planes: ductal arch, 13.9%; aortic arch, 10.5%; and venae cavae, 12.0%.

CONCLUSIONS

Based on our results, the FINE technique is an effective method, but its feasibility depends on the fetal position. The use of this semiautomatic work flow-based approach supports evaluation of the fetal heart in a standardized manner. Semiautomatic evaluation of the fetal heart might be useful in facilitating the detection of fetal cardiac anomalies.

Physician Barriers and Facilitators for Screening for Congenital Heart Disease With Routine Obstetric Ultrasound: A National United States Survey

OBJECTIVES

Prenatal detection of congenital heart disease with obstetric screening remains at less than 50% in most population studies, far from what is thought to be achievable. We sought to identify barriers/facilitators for screening from the perspective of interpreting physicians and to understand how these barriers/facilitators may be associated with interpretation of screening images.

METHODS

Our mixed-methods studies included 4 focus groups in centers across the United States with obstetric, maternal-fetal medicine, and radiology providers who interpreted obstetric ultrasound studies. Themes around barriers/facilitators for fetal heart screening were coded from transcripts. A national Web-based survey was then conducted, which quantitatively measured reported barriers/facilitators and measured physicians' ability to interpret fetal heart-screening images. Multivariable generalized linear random-effect models assessed the association between barriers/facilitators and the accuracy of image interpretation at the image level.

RESULTS

Three main themes were identified in the focus groups: intrinsic barriers (ie, comfort with screening), external barriers (ie, lack of feedback), and organizational barriers (ie, study volumes). Among 190 physician respondents, 104 interpreted ultrasound studies. Perceptions of barriers varied by practice setting, with nontertiary providers having lower self-efficacy and perceived usefulness of cardiac screening. Facilitators associated with the odds of accurate interpretation of screening images were knowledge (odds ratio, 2.54; P = .002) and the volume of scans per week (odds ratio, 1.01 for every additional scan; P = .04).

CONCLUSIONS

Some of the main barriers to cardiac screening identified and prioritized by physicians across the United States were knowledge of screening and minimal volumes of scans. Targeting these barriers will aid in improving prenatal detection of congenital heart disease.

Neonatal management of prenatally suspected coarctation of the aorta

OBJECTIVES

(a) To determine the false-positive rate among newborns with prenatally suspected coarctation of the aorta (CoA) within the UCLA Health system, (b) to compare patient and maternal interventions and outcomes between false-positive cases and normal controls, and (c) to determine the timing of clinical presentation of CoA.

METHODS

We performed a single-center, retrospective case control study of all fetuses with suspected isolated CoA who underwent both fetal echocardiographic evaluation and subsequent delivery at UCLA between January 1, 2011, and December 31, 2018. Maternal and neonatal medical records were reviewed for demographic and clinical data, for cases of suspected CoA and for controls. A separate review of our institution's surgical database was performed to identify characteristics of all patients (neonatal and pediatric) with isolated CoA who underwent surgical repair during the same time period.

RESULTS

Among the 50 fetal cases of isolated suspected CoA who delivered at our institution, 47 patients (94%) were found to be normal (false positives). Compared with normal controls, patients with suspected CoA were more likely to have delayed maternal bonding, delayed feeding, admission to the intensive care unit, performance of neonatal echocardiograms, initiation of intravenous fluids and initiation of prostaglandin E1, and a longer length of hospital stay. Among the 38 patients undergoing CoA repair at our institution during the study period, four patients were prenatally diagnosed and no patient presented clinically with symptoms before 48 hours after delivery.

CONCLUSION

Compared with normal controls, patients with prenatally suspected coarctation are more likely to have delayed maternal bonding, delayed feeding, more frequent neonatal echocardiograms, and longer length of hospital stay. Further refinement of neonatal management may improve postnatal care.

Low prenatal detection rate of valvar pulmonary stenosis: What are we missing?

OBJECTIVES

Critical pulmonary stenosis (PS) and pulmonary atresia with intact ventricular septum (PAIVS) require urgent neonatal intervention. Since PS may be more insidious than PAIVS during gestation, we hypothesized that neonates with PS would have lower rates of prenatal detection than PAIVS.

METHODS

We performed a retrospective chart review of all neonates who underwent diagnostic or interventional cardiac catheterization between 2000 and 2014 for critical PS or PAIVS. The rates of prenatal diagnosis were calculated for PS and PAIVS. Prenatal and postnatal echocardiographic data were reviewed.

RESULTS

178 patients met inclusion criteria: 91 with critical PS and 87 with PAIVS. The prenatal diagnosis rate for critical PS was lower than for PAIVS at 37% (34/91) vs 60% (52/87) (P = .003). At the time of diagnosis at a median gestational age of 25 weeks, the median TV z-score for patients with critical PS was larger than in PAIVS (-0.15 vs -3.0 P = .004).

CONCLUSION

Critical PS had a lower prenatal detection rate than PAIVS, likely due to a relatively normal 4-chamber view at the time of routine second trimester screening in patients with PS. Color flow Doppler of the outflow tracts may improve detection, since outflow tracts may appear normal by 2D imaging.

Is Fetal Intelligent Navigation Echocardiography Helpful in Screening for d-Transposition of the Great Arteries?

OBJECTIVES

To evaluate the performance of fetal intelligent navigation echocardiography (FINE) applied to spatiotemporal image correlation (STIC) volumes in generating 3 specific abnormal cardiac views (left ventricular outflow tract, right ventricular outflow tract, and 3-vessel and trachea) used to screen for d-transposition of the great arteries (d-TGA).

METHODS

In this prospective study, 1 or more STIC volumes were obtained from the 4-chamber view in 34 second- and third-trimester fetuses with d-TGA. Each appropriate STIC volume was evaluated by STICLoop (Samsung Medison, Seoul, Korea) before applying the FINE method. One optimal volume per fetus was selected by observers. The visualization rates of the 3 specific abnormal cardiac views of d-TGA and their diagnostic elements were calculated, and the reliability between 2 observers was verified by the intraclass correlation coefficient.

RESULTS

Fetal intelligent navigation echocardiography applied to STIC volume data sets of fetuses with d-TGA successfully generated the 3 specific abnormal cardiac views in the following manner for 2 observers: 75.0% (n = 21) for the left ventricular outflow tract, 89.2% (n = 25) for the right ventricular outflow tract, and 85.7% (n = 24) for the 3-vessel and trachea view. Twenty-four (85.7%) of the STIC volume data sets showed 2 or 3 of the abnormal cardiac views. The interobserver intraclass correlation coefficients between the 2 observers ranged from 0.842 to 1.000 (95% confidence interval), indicating almost perfect reliability for the 2 observers.

CONCLUSIONS

In cases of d-TGA, the FINE method has a high success rate in generating 3 specific abnormal cardiac views and therefore can be performed to screen for this congenital defect.

Semiautomatic Fetal Intelligent Navigation Echocardiography Has the Potential to Aid Cardiac Evaluations Even in Less Experienced Hands

OBJECTIVES

To investigate the interobserver and intraobserver variability and corresponding learning curve in a semiautomatic approach for a standardized assessment of the fetal heart (fetal intelligent navigation echocardiography [FINE]).

METHODS

A total of 30 stored spatiotemporal image correlation volume data sets of second-trimester fetuses were evaluated by 3 physicians with different levels of expertise in fetal echocardiography by using the FINE approach. Data were analyzed regarding the examination time and proper reconstruction of the diagnostic cardiac planes. The completions and numbers of correct depictions of all diagnostic planes were evaluated by a blinded expert (time t0). To determine interobserver and intraobserver variability, the volumes were reassessed after a 4-week training interval (time t1).

RESULTS

All operators were able to perform the investigation on all 30 volumes. At t0, the interobserver variability between the beginner and both the advanced (P = .0013) and expert (P < .0001) examiners was high. Focusing on intraobserver variability at t1, the beginner showed a marked improvement (P = .0087), whereas in advanced and expert hands, no further improvement regarding proper achievement of all diagnostic planes could be noticed (P > .999; P = .8383). The beginner also showed improvement in the mean investigation time (t0, 82.8 seconds; t1, 73.4 seconds; P = .0895); nevertheless, the advanced and expert examiners were faster in completing the examination (t1, advanced, 20.9 seconds; expert, 28.3 seconds; each P < .0001).

CONCLUSIONS

Based on our results, the FINE technique is a reliable and easily learned method. The use of this semiautomatic work flow-based approach supports evaluation of the fetal heart in a standardized and time-saving manner. A semiautomatic evaluation of the fetal heart might be useful in facilitating the detection of fetal cardiac anomalies.

The Fetal 3-Vessel Views: An Illustrative Case-Based Tutorial

In 2018, the American Institute of Ultrasound in Medicine revised its obstetric Practice Parameter for the second-trimester fetal anatomic survey. The 2018 Practice Parameter recommends incorporation of the 3-vessel view and 3-vessel and trachea view "if technically feasible." Sonographers and other medical providers may require additional training and education to develop greater proficiency in obtaining and interpreting these views. This pictorial essay, including ultrasound images alongside their respective schematic diagrams, provides an up-to-date, practical, and clinically oriented review of the 3-vessel view and 3-vessel and trachea view and their most common presentations in the context of congenital heart disease.

Barriers to Sonographer Screening for Fetal Heart Defects: A U.S. National Survey

OBJECTIVE

We surveyed obstetric sonographers, who are at the forefront of the screening process to determine how barriers to prenatal cardiac screening impacted screening abilities.

METHODS

We performed a cross-sectional national survey of obstetric sonographers in the United States using a sampling frame from American Registry of Diagnostic Medical Sonography mailing lists. The web survey measured the ability to obtain and interpret fetal heart images. Several cognitive, sociodemographic, and system-level factors were measured, including intention to perform cardiac imaging. Regression and mediation analyses determined factors associated with intention to perform and ability to obtain and interpret cardiac images. Subgroup analyses of sonographers in tertiary versus nontertiary centers were also performed.

RESULTS

Survey response rate either due to noncontact or nonresponse was 40%. Of 480 eligible sonographers, ~30% practiced in tertiary settings. Sonographers had lower intention to perform outflow views compared to 4 chambers. Higher self-efficacy and professional expectations predicted higher odds of intention to perform outflow views (OR 2.8, 95% CI 1.9-4.2 and 1.9, 95% CI 1.1-3.0, respectively). Overall accuracy of image interpretation was 65% (±14%). For the overall cohort and nontertiary subgroup, higher intention to perform outflows was associated with increased accuracy in overall image interpretation. For the tertiary subgroup, self-efficacy and feedback were strongly associated with accuracy.

CONCLUSIONS

We identified several modifiable (some heretofore unrecognized) targets to improve prenatal cardiac screening. Priorities identified by sonographers that are associated with screening success should guide future interventions.

Detailed Fetal Anatomic Ultrasound Examination: Effect of the 2014 Consensus Report on a Tertiary Referral Center

This study evaluates the impact of extended cardiac views on examination time, repeat imaging, and anomaly detection before and after implementation of 76811 guidelines (American Institute of Ultrasound in Medicine Consensus 2014). It is a retrospective study of singleton pregnancies undergoing detailed ultrasound imaging at 18 weeks' gestation or greater before and after the protocol change in an academic, tertiary care fetal center. Views required prior to 2014: 4-chamber, left outflow tract, right outflow tract. Additional views required after 2014: bicaval, aortic arch, 3-vessel, and 3-vessel trachea. Fetuses with known anomalies were excluded. Rates of detection of congenital heart disease (CHD), examination completion, repeat examination recommendation, fetal echocardiogram recommendation, completion by body mass index, and cardiac examination time were determined. Six hundred twenty-four subjects were included, 217 before and 407 after protocol change. Views obtained were as stated in the American Institute of Ultrasound in Medicine/Society for Maternal-Fetal Medicine consensus. Detection of CHD was not improved. Examination times increased by 20% (6.4 vs 7.7 minutes, P < 0.05). Number of incomplete studies increased by 130% (11% to 26%, P < 0.05). Twice as many patients were referred for repeat examination (6% vs 13%, P < 0.05). Completion rates were negatively correlated with body mass index. Recommendations for fetal echocardiogram were unchanged (5% vs 6%, P = 0.6). Additional imaging did not increase detection rate of CHD (3% vs 2%, P = 0.3). Extended cardiac views resulted in increased examination time, more incomplete examinations, and more repeat examinations without changing detection rates of CHD.

Prenatal diagnosis and prevalence of critical congenital heart defects: an international retrospective cohort study

OBJECTIVES

To assess international trends and patterns of prenatal diagnosis of critical congenital heart defects (CCHDs) and their relation to total and live birth CCHD prevalence and mortality.

SETTING

Fifteen birth defect surveillance programmes that participate in the International Clearinghouse for Birth Defects Surveillance and Research from 12 countries in Europe, North and South America and Asia.

PARTICIPANTS

Live births, stillbirths and elective terminations of pregnancy for fetal anomaly diagnosed with 1 of 12 selected CCHD, ascertained by the 15 programmes for delivery years 2000 to 2014.

RESULTS

18 243 CCHD cases were reported among 8 847 081 births. The median total prevalence was 19.1 per 10 000 births but varied threefold between programmes from 10.1 to 31.0 per 10 000. CCHD were prenatally detected for at least 50% of the cases in one-third of the programmes. However, prenatal detection varied from 13% in Slovak Republic to 87% in some areas in France. Prenatal detection was consistently high for hypoplastic left heart syndrome (64% overall) and was lowest for total anomalous pulmonary venous return (28% overall). Surveillance programmes in countries that do not legally permit terminations of pregnancy tended to have higher live birth prevalence of CCHD. Most programmes showed an increasing trend in prenatally diagnosed CCHD cases.

DISCUSSION AND CONCLUSIONS

Prenatal detection already accounts for 50% or more of CCHD detected in many programmes and is increasing. Local policies and access likely account for the wide variability of reported occurrence and prenatal diagnosis. Detection rates are high especially for CCHD that are more easily diagnosed on a standard obstetric four-chamber ultrasound or for fetuses that have extracardiac anomalies. These ongoing trends in prenatal diagnosis, potentially in combination with newborn pulse oximetry, are likely to modify the epidemiology and clinical outcomes of CCHD in the near future.

Emerging trends in the prenatal diagnosis of complex CHD and its influence on infant mortality in this cohort

BACKGROUND

Fetal echocardiography is the main modality of prenatal diagnosis of CHD. This study was done to describe the trends and benefits associated with prenatal diagnosis of complex CHD at a tertiary care centre.

METHODS

Retrospective chart review of patients with complex CHD over an 18-year period was performed. Rates of prenatal detection along with early and late infant mortality outcomes were studied.

RESULTS

Of 381 complex CHD patients born during the study period, 68.8% were diagnosed prenatally. Prenatal detection rate increased during the study period from low-50s in the first quarter to mid-80s in the last quarter (p=0.001). Rate of detection of conotruncal anomalies increased over the study period. No infant mortality benefit was noted with prenatal detection.

CONCLUSIONS

Improved obstetrical screening indications and techniques have contributed to higher proportions of prenatal diagnosis of complex CHD. However, prenatal diagnosis did not confer survival benefits in infancy in our study.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prenatal detection of critical cardiac outflow tract anomalies remains suboptimal despite revised obstetrical imaging guidelines

BACKGROUND

Fetal echocardiography can accurately diagnose critical congenital heart disease prenatally, but relies on referrals from abnormalities identified on routine obstetrical ultrasounds. Critical congenital heart disease that is frequently missed due to inadequate outflow tract imaging includes anomalies such as truncus arteriosus, double outlet right ventricle, transposition of the great arteries, tetralogy of Fallot, pulmonary stenosis, and aortic stenosis.

OBJECTIVE

This study evaluated the prenatal detection rate of critical outflow tract anomalies in a single urban pediatric hospital before and after "AIUM Practice Guideline for the Performance of Obstetric Ultrasound Examinations," which incorporated outflow tract imaging.

DESIGN

Infants with outflow tract anomalies who required cardiac catheterization and/or surgical procedure(s) in the first 3 months of life were retrospectively identified. This study evaluated two time periods; pre-guidelines from June 2010 to May 2013 and post-guidelines from January 2015 to June 2016. June 2013-December 2014 was excluded as a theoretical period necessary for obstetrical practices to implement the revised guidelines.

RESULTS

Overall, prenatal diagnosis occurred in 55% of infants with critical outflow tract anomalies; of the three most common defects, prenatal diagnosis occurred in 53% of D-transposition of the great arteries, 63% of tetralogy of Fallot, and 80% of double outlet right ventricle patients. Pre-guidelines, prenatal diagnosis occurred in 52% (52 of 102) infants with critical outflow tract anomalies requiring early cardiac intervention. Post-guidelines, prenatal diagnosis occurred in 61% (33 of 54) infants, not significantly different than the prenatal detection rate pre-guidelines (P = .31).

CONCLUSIONS

Despite revised obstetrical guidelines highlighting the importance of outflow tract imaging, referrals and prenatal diagnosis of these types of critical congenital heart disease remain low. Education of obstetrical sonographers and practitioners who perform fetal anatomic screening is vital to increase referrals and prenatal detection of critical outflow tract anomalies.

Advancing Prenatal Detection of Congenital Heart Disease: A Novel Screening Protocol Improves Early Diagnosis of Complex Congenital Heart Disease

OBJECTIVES

Prenatal diagnosis of complex congenital heart disease (CHD) during routine obstetric ultrasound (US) examinations improves postnatal outcomes, but sensitivity is low (<40%). Our objective was to improve our prenatal detection of complex CHD with implementation of a specific screening protocol.

METHODS

From January 2003 to December 2013, 506 consecutive confirmed cases of complex CHD in the province of Manitoba, Canada, were analyzed to compare the sensitivity and positive predictive value of prenatal US detection of complex CHD before and after the introduction of a novel prenatal screening protocol. The intervention was done in October 2004, emphasizing screening and not diagnosis of complex CHD. It involved education, practical scanning tips, a checklist, and feedback on cases. We also assessed the effect of the intervention in different screening settings: community hospitals, tertiary hospitals, and fetal assessment units.

RESULTS

The sensitivity for detecting complex CHD increased from 29.8% to 88.3% (P < .0001), while the positive predictive value remained high. The largest improvement in detection was found for US units in community hospitals (52.4% higher; P < .0001), followed by tertiary hospitals (39.9%; P = .0004), and fetal assessment units (7.2%; P = .16). Additionally, there was a significant decrease in the presentation of neonates in critical condition from before to after the implementation (24.3% to 13.1%, respectively; P = .0165).

CONCLUSIONS

Implementing a focused routine prenatal screening protocol can vastly improve detection rates of critical cardiac abnormalities. The improvement in community hospitals was particularly important because early detection ensured that the birth was planned to take place in an appropriate facility. Our novel protocol can be performed by all sonographers, regardless of experience, equipment used, and hospital setting.

Perinatal and early postnatal outcomes for fetuses with prenatally diagnosed d-transposition of the great arteries: a prospective cohort study assessing the effect of standardised prenatal consultation

BACKGROUND

The aim of this study was to explore perinatal and early postnatal outcomes in fetuses with prenatally diagnosed d-transposition of the great arteries and impacts of standardised prenatal consultation.

METHODS

All fetuses with prenatally diagnosed d-transposition of the great arteries prospectively enrolled at South China cardiac centre from 2011 to 2015. Standardised prenatal consultation was introduced in 2013 and comprehensive measures were implemented, such as establishing fetal CHD Outpatient Consultation Service, performing standard prenatal consultation according to specifications, and establishing a multidisciplinary team with senior specialists performing in-person consultations. Continuous follow-up investigation was conducted. Perinatal and postnatal outcomes were compared before and after consultation including live birth, elective termination of pregnancy, spontaneous fetal death, stillbirths, referral for surgery, and survival.

RESULTS

In all, 146 fetuses were enrolled with 41 (28%) lost to follow-up. Among 105 remaining fetuses, 29 (28%) were live births and 76 (72%) were terminated. After consultation, live birth rate was higher (50 versus 33%) and termination rate was lower (50 versus 76%), although there was no statistical significance. Excluding three live births without postnatal d-transposition of the great arteries, 65% (17/26) underwent arterial switch operation within 30 days. A total of three in-hospital deaths occurred and during the 10-month follow-up period, one death was observed. In one case, the switch procedure was performed at 13 months and the infant survived. Out of eight infants without arterial switch operation, two died.

CONCLUSIONS

Live birth rate increased after consultation; however, termination remained high. Combining termination, patients without arterial switch operation, and operative mortality, outcomes of d-transposition of the great arteries infants can be improved. Standard consultation, multidisciplinary collaboration, and improved perinatal care are important to improve outcomes.

Sonographer-Identified Barriers and Facilitators to Prenatal Screening for Congenital Heart Disease

Background: Fetal ultrasound screening for congenital heart disease has high detection rates in efficacy studies but not in practice. We investigated sonographers’ perspectives on barriers to screening and their association with intermediate measures of cardiac imaging. Methods: Barriers to fetal heart screening were identified in focus groups with obstetric sonographers. A web-based survey measured reported barriers and sonographers’ ability to interpret fetal heart screening images. Generalized linear random effect models assessed associations between barriers and image interpretation. Results: Four themes were identified: intrinsic barriers (self-efficacy), external barriers (time), informational needs, and provider and patient expectations. Among 224 sonographers surveyed, an average of 77.6% of fetal heart images were interpreted correctly. Perceptions about self-efficacy ( P = .03) and ease of performing imaging ( P = .01) were associated with accuracy of image interpretation. Conclusions: Several sonographer-identified barriers associated with image interpretation may be novel targets for improving prenatal detection of congenital heart disease.

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.

Identification of fetal cardiac anatomy and hemodynamics: a novel enhanced screening protocol

Background

Prenatal cardiac screening is of great importance as it contributes to appropriate neonatal management and helps parents to make a decision regarding their pregnancy. The aim of our study was to evaluate the efficiency of a newly proposed screening protocol in the detection of fetal congenital heart disease (CHD).

Methods

This was a prospective study. A total of 52 cases of confirmed CHD fetuses and 248 cases of randomly selected normal fetuses were included in the study. Two sonographers with similar experience performed the cardiac screenings under two different protocols independently. The conventional protocol (Protocol A) paid greater attention to the four-chamber view and the outflow tract views. A 6-month training program was provided to sonographers performing scans under the new protocol (Protocol B), which emphasized systematically evaluating fetal cardiac anatomy and hemodynamics. Color Doppler was mandatory and some ultrasonic signs for special cardiac anomalies were also introduced into this protocol.

Results

Protocol B detected more cardiac anomalies than did Protocol A (96.2 % vs. 61.5 %, P < 0.01). Specifically, Protocol B was superior to Protocol A in detecting cardiac malpositions, abnormal systemic and pulmonary venous connection, right aortic arch, transposition of the great arteries, and congenital corrected transposition of the great arteries. By visualizing flow disturbance and retrograde flow with color Doppler, Protocol B was better than Protocol A in screening valvular associated malformations, such as pulmonary atresia, pulmonary stenosis, tricuspid dysplasia, etc. For the normal fetuses, Protocol B was better than Protocol A in reducing the false-positive detection of septal defects.

Conclusions

The current study introduces an enhanced protocol for fetal cardiac screening, under which the obstetric screening sonographers systematically identify fetal cardiac anatomy and hemodynamics. A short-term training program makes it possible for the screening sonographers to become familiar with the new protocol, and its value has been confirmed due to improvements made in screening efficiency.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-0933-9) contains supplementary material, which is available to authorized users.

Prospective evaluation of the fetal heart using Fetal Intelligent Navigation Echocardiography (FINE)

OBJECTIVE

To evaluate prospectively the performance of Fetal Intelligent Navigation Echocardiography (FINE) applied to spatiotemporal image correlation (STIC) volume datasets of the normal fetal heart.

METHODS

In all women between 19 and 30 weeks' gestation with a normal fetal heart, an attempt was made to acquire STIC volume datasets of the apical four-chamber view if the following criteria were met: (1) fetal spine located between 5- and 7-o'clock positions; (2) minimal or absent shadowing (including a clearly visible transverse aortic arch); (3) absence of fetal breathing, hiccups, or movement; and (4) adequate image quality. Each STIC volume successfully acquired was evaluated by STICLoop™ to determine its appropriateness before applying the FINE method. Visualization rates of fetal echocardiography views using diagnostic planes and/or Virtual Intelligent Sonographer Assistance (VIS-Assistance®) were calculated.

RESULTS

One or more STIC volumes (365 in total) were obtained successfully in 72.5% (150/207) of women undergoing ultrasound examination. Of the 365 volumes evaluated by STICLoop, 351 (96.2%) were considered to be appropriate. From the 351 STIC volumes, only one STIC volume per patient (n = 150) was analyzed using the FINE method, and consequently nine fetal echocardiography views were generated in 76-100% of cases using diagnostic planes only, in 98-100% of cases using VIS-Assistance only, and in 98-100% of cases when using a combination of diagnostic planes and/or VIS-Assistance.

CONCLUSIONS

In women between 19 and 30 weeks' gestation with a normal fetal heart undergoing prospective sonographic examination, STIC volumes can be obtained successfully in 72.5% of cases. The FINE method can be applied to generate nine standard fetal echocardiography views in 98-100% of these cases using a combination of diagnostic planes and/or VIS-Assistance. This suggests that FINE could be implemented in fetal cardiac screening programs. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Optimal visualization of the fetal four-chamber and outflow tract views with transabdominal ultrasound in the morbidly obese: Are we there yet?

BACKGROUND

To compare optimal visualization of the four-chamber and outflow-tract views of the fetal heart on sonographic examination between morbidly obese (body mass index [BMI] ≥ 40 kg/m(2) ) and nonobese (BMI < 25 kg/m(2) ) pregnant women.

METHODS

In this retrospective cohort study, we included records and images from 509 pregnant women who had first undergone sonographic examination between 18 and 36 weeks' fetal gestational age.

RESULTS

Compared with the nonobese women, morbidly obese women had lower optimal visualization of the four-chamber and outflow-tract heart views: four-chamber view, morbidly obese, 83/186 (44.6%), versus nonobese, 283/323 (87.6%), and outflow-tract view, morbidly obese, 80/186 (43%) versus nonobese, 258/290 (89%); p < 0.0001 for each comparison. Similar outcomes were observed when the results from each subcategory of morbidly obese women (ie, BMI 40-49.9, 50-59.9, and ≥60 kg/m(2) ) were compared with that from nonobese women; p < 0.0001 for each comparison. These outcomes remained the same regardless of whether this comparison was made among those who had their examination before or at 19 weeks' or more gestational age. Among the morbidly obese women, there was no difference in optimal visualization of the four-chamber or outflow-tract views regardless of whether the examination was performed at <23 weeks' or at ≥23 weeks' gestational age: four-chamber view <23 weeks, 44.8% (78/174), versus four-chamber view ≥23 weeks, 41.7% (5/12); p = 0.8, and outflow-tract view <23 weeks, 43.1% (75/174), versus outflow-tract view ≥23 weeks, 41.7% (5/12); p = 0.9. After controlling for maternal age and race, the odds of visualizing the four-chamber and outflow-tract views in the morbidly obese were reduced compared with those in their nonobese counterparts: odds ratio (OR) for four-chamber, 0.13; 95% confidence interval (CI), 0.08-0.21, and OR for outflow-tract, 0.11; 95% CI, 0.07-0.17.

CONCLUSIONS

Optimal visualization of the fetal four-chamber and outflow-tract views was achieved in less than 50% of morbidly obese women, compared with almost 90% in nonobese women.

Variation in Prenatal Diagnosis of Congenital Heart Disease in Infants

BACKGROUND AND OBJECTIVE

Prenatal diagnosis allows improved perioperative outcomes for fetuses with certain forms of congenital heart disease (CHD). Variability in prenatal diagnosis has been demonstrated in other countries, leading to efforts to improve fetal imaging protocols and access to care, but has not been examined across the United States. The objective was to evaluate national variation in prenatal detection across geographic region and defect type in neonates and infants with CHD undergoing heart surgery.

METHODS

Cardiovascular operations performed in patients ≤6 months of age in the United States and included in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2006-2012) were eligible for inclusion. Centers with >15% missing prenatal diagnosis data were excluded from the study. Prenatal diagnosis rates were compared across geographic location of residence and defect type using the χ(2) test.

RESULTS

Overall, the study included 31,374 patients from 91 Society of Thoracic Surgeons Congenital Heart Surgery Database participating centers across the United States. Prenatal detection occurred in 34% and increased every year, from 26% (2006) to 42% (2012). There was significant geographic variation in rates of prenatal diagnosis across states (range 11.8%-53.4%, P < .0001). Significant variability by defect type was also observed, with higher rates for lesions identifiable on 4-chamber view than for those requiring outflow tract visualization (57% vs 32%, P < .0001).

CONCLUSIONS

Rates of prenatal CHD detection in the United States remain low for patients undergoing surgical intervention, with significant variability between states and across defect type. Additional studies are needed to identify reasons for this variation and the potential impact on patient outcomes.

Prenatal diagnosis of transposition of the great arteries over a 20-year period: improved but imperfect

OBJECTIVE

To evaluate temporal trends in the prenatal diagnosis of transposition of the great arteries with intact ventricular septum (TGA/IVS) and its impact on neonatal morbidity and mortality.

METHODS

We included in this study cohort newborns with TGA/IVS who were referred for surgical management to our center over a 20-year period (1992-2011). The study period was divided into five 4-year periods and the primary outcome was rate of prenatal diagnosis. Secondary outcomes included neonatal preoperative status and perioperative survival.

RESULTS

Of the 340 patients with TGA/IVS, 81 (23.8%) had a prenatal diagnosis. The rate of prenatal diagnosis increased over the study period, from 6% in 1992-1995 to 41% in 2008-2011 (P < 0.001). Compared to patients with a postnatal diagnosis, balloon atrial septostomy (BAS) was performed earlier in patients with a prenatal diagnosis (0 days after delivery vs 1 day after delivery, respectively; P < 0.001) and fewer prenatally diagnosed neonates required mechanical ventilation (55.6% vs 68.0%; P = 0.03). Between patients with a prenatal or postnatal diagnosis of TGA/IVS, there were no statistically significant differences in the incidence of preoperative acidosis (16.0% vs 25.5%; P = 0.1), need for preoperative extracorporeal membrane oxygenation (2.5% vs 2.7%; P = 1.0) or mortality (one preoperative and no postoperative deaths among prenatally diagnosed patients compared with four preoperative and six postoperative deaths among postnatally diagnosed patients).

CONCLUSIONS

The prenatal detection rate of TGA/IVS has improved but still remains below 50%, suggesting the need for strategies to increase detection rates. The mortality rate was not statistically significantly different between prenatally and postnatally diagnosed patients, however, there were significant preoperative differences with regard to earlier BAS and fewer neonates that required mechanical ventilation. Ongoing work is required to ascertain whether prenatal diagnosis confers long-term benefits.

Low rate of prenatal diagnosis among neonates with critical aortic stenosis: insight into the natural history in utero

OBJECTIVES

To better understand the natural history and spectrum of fetal aortic stenosis (AS), we aimed to (1) determine the prenatal diagnosis rate of neonates with critical AS and a biventricular (BV) outcome, and (2) describe the findings at fetal echocardiography in patients diagnosed prenatally.

METHODS

A multicenter, retrospective study was performed on neonates who presented with critical AS and who were discharged with a BV outcome from 2000 to 2013. The prenatal diagnosis rate was compared with that reported for hypoplastic left heart syndrome (HLHS). We reviewed fetal echocardiographic findings in patients who were diagnosed prenatally.

RESULTS

In only 10 (8.5%) of 117 neonates with critical AS and a BV outcome was the diagnosis made prenatally, a rate significantly lower than that for HLHS in the contemporary era (82%; P < 0.0001). Of the 10 patients diagnosed prenatally, all had developed left ventricular dysfunction by a median gestational age of 33 (range, 28-35) weeks. When present, Doppler abnormalities such as retrograde flow in the aortic arch (n = 2), monophasic mitral inflow (n = 3) and left-to-right flow across the foramen ovale (n = 8) developed late in gestation (median 33 weeks).

CONCLUSION

The prenatal diagnosis rate of critical AS and a BV outcome among neonates is very low, probably owing to a relatively normal four-chamber view in mid-gestation with development of significant obstruction in the third trimester. The natural history contrasts with that of severe mid-gestation AS with evolving HLHS and suggests that the gestational timing of development of significant AS has an important impact on subsequent left-heart growth in utero.

Moving towards universal prenatal detection of critical congenital heart disease in southern Nevada: a community-wide program

This study compares the current, prenatal detection rate for critical congenital heart disease in Southern Nevada with the previously reported rate, after developing and expanding a comprehensive, community-wide fetal cardiology program. For the current-period analysis, we inquired our database and electronic health records for patients born in Clark County, Nevada, with critical congenital heart disease between May 2012 and April 2014, and we compared the results with the previous period between May 2003 and April 2006. The major components of the community-wide program include fetal congenital heart disease screening via general obstetric ultrasound studies performed in obstetrician's offices, radiology imaging centers, or maternal-fetal medicine specialty practices; subsequent referral for comprehensive fetal echocardiography performed in maternal-fetal medicine offices under the on-site supervision by fetal cardiologists; and recurring community educational programs teaching the 5-axial plane, fetal echocardiographic screening protocol to general obstetric sonographers and instructing perinatal sonographers in advanced imaging topics. For the current period, the prenatal detection rate for critical congenital heart disease in Southern Nevada was 71 versus 36% for the previous period (p < 0.001). The temporal improvement in prenatal detection of critical congenital heart disease may be related to our expanded decentralized, community-wide fetal cardiology program, and our experiences may be applicable to other metropolitan areas.

Diagnosis of congenital heart disease in an era of universal prenatal ultrasound screening in southwest Ohio

OBJECTIVES

Diagnostic ultrasound is widespread in obstetric practice, yet many babies with major congenital heart disease remain undiagnosed. Factors affecting prenatal diagnosis of major congenital heart disease are not well understood. This study aims to document prenatal detection rates for major congenital heart disease in the Greater Cincinnati area, and identify factors associated with lack of prenatal diagnosis.

METHODS

All living infants diagnosed with major congenital heart disease by 4 months of age at our centre were prospectively identified. Prenatal care data were obtained by parent interview. Neonatal records were reviewed for postnatal data. Obstetricians were contacted for diagnostic ultrasound data.

RESULTS

A total of 100 infants met the inclusion criteria. In all, 95 infants were analysed, of whom 94 were offered diagnostic ultrasound. In all, 41 had a prenatal diagnosis of major congenital heart disease. The rate of prenatal detection varied by cardiac lesion, with aortic arch abnormalities, semilunar valve abnormalities, and venous anomalies going undetected in this sample. Among subjects without prenatal detection, the highest proportion consisted of those having Level 1 diagnostic ultrasound only (66%). Prenatal detection was not significantly influenced by maternal race, education level, income, or insurance type.

CONCLUSIONS

Despite nearly universal diagnostic ultrasound, detection rates of major congenital heart disease remain low in southwest Ohio. An educational outreach programme including outflow tract sweeps for community-level obstetrical personnel may improve detection rates.

Pediatric prenatal diagnosis of congenital heart disease

PURPOSE OF REVIEW

Fetal cardiology is a rapidly evolving field. Imaging technology continues to advance as do approaches to in-utero interventions and care of the critically ill neonate, with even greater demand for improvement in prenatal diagnosis of congenital heart disease (CHD) and arrhythmias.

RECENT FINDINGS

Reviewing the advances in prenatal diagnosis of CHD in such a rapidly developing field is a broad topic. Therefore, we have chosen to focus this review of recent literature on challenges in prenatal detection of CHD, challenges in prenatal counseling, advances in fetal arrhythmia diagnosis, and potential benefits to patients with CHD who are identified prenatally.

SUMMARY

As methods and tools to diagnose and manage CHD and arrhythmias in utero continue to improve, future generations will hopefully see a reduction in both prenatal and neonatal morbidity and mortality. Prenatal diagnosis can and should be used to optimize location and timing of delivery and postnatal interventions.

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.

Second trimester cardiac diagnosis: screening standards and outcomes

Second trimester screening for congenital heart defects occurs during the routine 18-20 weeks' anomaly scan in many countries. Most congenital heart defects can be prenatally detected by experts in foetal echocardiography working in tertiary centres with high-risk pregnancies. Many studies, however, have shown that detection rates obtained by experts are not reproducible in the low-risk peripheral practices where most of the foetal screening takes place. As the majority of foetuses with congenital heart defects are born to mothers with no identifiable risk factors, it is important that widespread screening of the low-risk population occurs. To facilitate this, standard protocols have been introduced in several countries, but they are not universal and have differing sensitivities depending on the screening views advocated and the area studied. Initially, only performing the four-chamber view (basic scan) was advocated. By adding the outflow tract views (extended scan), three-vessel, and laterality views, the sensitivity of the examination can be significantly increased. Unfortunately, the sensitivity of these extended protocols still does not meet that obtainable in experienced hands, reflecting the additional skill required to obtain these extended views. Thus, close links are required between the tertiary centres and the screening centres to teach and maintain the skills required to obtain and interpret the required views, and to support the sonographer's commitment. Furthermore, an audit system is required to trace false-positive and -negative cases so that targeted interventions can be planned. This is important, as a missed case of prenatal congenital heart defect is potentially a missed opportunity to reduce postnatal morbidity and mortality.

Cost-effectiveness of prenatal screening strategies for congenital heart disease

OBJECTIVE

The economic implications of strategies to improve prenatal screening for congenital heart disease (CHD) in low-risk mothers have not been explored. The aim was to perform a cost-effectiveness analysis of different screening methods.

METHODS

We constructed a decision analytic model of CHD prenatal screening strategies (four-chamber screen (4C), 4C + outflow, nuchal translucency (NT) or fetal echocardiography) populated with probabilities from the literature. The model included whether initial screens were interpreted by a maternal-fetal medicine (MFM) specialist and different referral strategies if they were read by a non-MFM specialist. The primary outcome was the incremental cost per defect detected. Costs were obtained from Medicare National Fee estimates. A probabilistic sensitivity analysis was undertaken on model variables commensurate with their degree of uncertainty.

RESULTS

In base-case analysis, 4C + outflow referred to an MFM specialist was the least costly strategy per defect detected. The 4C screen and the NT screen were dominated by other strategies (i.e. were more costly and less effective). Fetal echocardiography was the most effective, but most costly. On simulation of 10 000 low-risk pregnancies, 4C + outflow screen referred to an MFM specialist remained the least costly per defect detected. For an additional $580 per defect detected, referral to cardiology after a 4C + outflow was the most cost-effective for the majority of iterations, increasing CHD detection by 13 percentage points.

CONCLUSIONS

The addition of examination of the outflow tracts to second-trimester ultrasound increases detection of CHD in the most cost-effective manner. Strategies to improve outflow-tract imaging and to refer with the most efficiency may be the best way to improve detection at a population level.

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.