Cardiac screening examination of the fetus: guidelines for performing the 'basic' and 'extended basic' cardiac scan

The reference ranges for fetal ductus venosus flow velocities and calculated waveform indices and their predictive values for right heart diseases

OBJECTIVES

This study endeavors to establish comprehensive normal reference ranges and Z score formulas for ductus venosus (DV) flow velocity parameters and calculated waveform indices across different gestational ages in low-risk fetuses. Furthermore, we aim to validate the predictive capabilities of these Z score calculation formulas in fetuses with diverse right heart diseases.

METHODS

A total of 8,953 singleton low-risk fetuses and 70 fetuses diagnosed with different types of right heart diseases were retrospectively enrolled. The DV blood flow velocities during the cardiac cycle (ventricular systolic wave velocity [S], ventricular diastolic wave velocity [D], atrial contraction wave velocity [A], and time-averaged maximum velocity [Tamx]) and calculated waveform indices (preload index [PLI], peak velocity index [PVI], pulsatility index [PI], S/A, and S/D) were obtained. Ninety low-risk fetuses were randomly selected as the control group to verify the predictive value of the Z score model for fetuses with different types of right heart diseases.

RESULTS

As gestational age increased (16-39 weeks), the mean values of S, D, A, and Tamx progressively increased; conversely, the mean values of PLI, PVI, PI, and S/A decreased, respectively, and the median value of S/D remained stable. The Z score-transformed A, PLI, PVI, PI, and S/A could serve as predictors of overall right heart diseases. Different DV Doppler parameter Z scores exhibited varying predictive values for different subtypes of right heart diseases.

CONCLUSIONS

Normal reference ranges and corresponding Z score calculation formulas for DV hemodynamic parameters were established, which have demonstrated significant diagnostic values in identifying right heart diseases.

Normal fetal echocardiography ratios - a multicenter cross-sectional retrospective study

OBJECTIVES

Normal fetal echocardiography ratios reflect blood flow balance and developmental patterns, providing a basis for more accurate diagnosis and prediction of congenital heart disease in fetuses. Despite its significance, standardized studies with ample samples are lacking. We aim to establish reference ranges for fetal cardiac structural parameters and hemodynamics using extensive multicenter data, including 11 ratios, and to clarify how these ratios change with gestational age.

METHODS

This is a multicenter cross-sectional retrospective study. 23,313 normal fetal echocardiographic examinations were enrolled from three medical centers. Analysis included 11 fetal cardiac-related ratios, such as right/left heart diameter ratio, mitral and tricuspid valve E/A-wave velocity ratio. To determine the reference ranges for various ratios across different gestational ages, a nonparametric quantile regression model, which does not presuppose normality, was utilized. The study investigated how the ratios change with gestational age by examining nonparametric regression plots and their first and second derivatives.

RESULTS

We established normal percentile reference ranges for 11 ratios at each gestational day. Analysis of ratio changes across gestation reveals several key patterns: The right heart system consistently dominates, with the right heart/left heart internal diameter ratio accelerating from 21.7 weeks of gestation; throughout fetal development, the E/A ratio of the mitral and tricuspid valves initially remains below one but increases progressively with gestational age, both reaching their maximum growth rates at week 25.7.

CONCLUSIONS

This study provides new references for routine obstetric screening, may enhance the understanding of the growth and developmental patterns of normal fetal hearts.

Artificial intelligence based automatic classification, annotation, and measurement of the fetal heart using HeartAssist

This study evaluated the feasibility of HeartAssist, a novel automated tool designed for classification of fetal cardiac views, annotation of cardiac structures, and measurement of cardiac parameters. Unlike previous AI tools that primarily focused on classification, HeartAssist integrates classification, annotation and measurement capabilities, enabling a more comprehensive fetal cardiac assessment.Cardiac images from fetuses (gestational ages 20-40 weeks) were collected at Asan Medical Center between January 2016 and October 2018. HeartAssist was developed using convolutional neural networks to classify 10 cardiac views, annotate 26 structures, and measure 43 parameters. One expert performed manual classifications, annotations, and measurements, which were then compared to HeartAssist outputs to assess feasibility. A total of 65,324 images from 2,985 fetuses were analyzed. HeartAssist achieved 99.4% classification accuracy, with recall, precision, and F1-score of 0.93, 0.95, and 0.94, respectively. Annotation accuracy was 98.4%, while the automatic measurement success rate was 97.6%, with an error rate of 7.62% and caliper similarity of 0.613. HeartAssist is a reliable tool for fetal cardiac screening, demonstrating high accuracy in classifying cardiac views and annotating structures, with comparable outcomes in measuring cardiac parameters. This tool could enhance prenatal detection of congenital heart disease and improve perinatal outcomes.

Incidence and Antenatal Detection of Congenital Heart Malformations-Data from a Tertiary Obstetric Romanian Center

OBJECTIVES

Congenital heart defects (CHDs) are among the most frequent congenital defects, and they significantly burden the healthcare system due to their high mortality rate and high cost of care for survivors. We aimed to highlight the incidence of CHDs in a tertiary center in Western Romania.

METHODS

A retrospective study was carried out between 2018 and 2022 at the "Pius Brinzeu" Emergency County Hospital Timisoara. Relevant information about the mothers and the newborns were collected and statistically analyzed.

RESULTS

The incidence of CHDs from 2018 to 2022 in our center was 5.3%. Eleven types of malformations were diagnosed postnatally in 541 newborns, with 28.8% of cases having more than one type of CHD. The antenatal detection rate was 28%, with the highest rates for tetralogy of Fallot, hypoplastic left heart syndrome, or significant ventricular septal defects and the lowest for pulmonary stenosis. The lower antenatal detection rate was influenced mainly by incomplete or absent prenatal care.

CONCLUSIONS

The incidence of CHDs is clearly dependent of a multifactorial approach, and the results highlight this. With an incidence almost 50% lower than reported within the literature and a low rate of prenatal detections, CHDs could be a more of a burden to endure regarding medical treatment. Improvements in patients' education, prenatal care, and screening programs could improve diagnosis, decrease mortality, and optimize postnatal care.

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).

Prenatal Diagnosis and Postnatal Outcomes of Persistent Left Superior Vena Cava Associated With Mild Narrow Aorta: A Cohort Study

PURPOSE

To explore prenatal ultrasonic features and prognosis of the persistent left superior vena cava (PLSVC) complicated with mild narrow aorta.

MATERIALS AND METHODS

A retrospective study was conducted involving 1348 fetuses diagnosed with PLSVC prenatally between January 2016 and December 2019. Forty-five fetuses with PLSVC associated with mild narrow aorta were selected from the cohort as the study group and 79 fetuses with isolated PLSCV were recruited randomly as the control group. All clinical and ultrasound results, including images and parameters of cardiac structures, were reviewed retrospectively. General conditions, ultrasound (US) measurements, and fetal prognosis were compared between the groups.

RESULTS

Aorta valve diameter (AOD), Z-score of aorta valve (AODz-score), aortic isthmus diameter (AOIsD), and pulmonary diameter (PAD)/AOD were significantly different in study group than control group no matter in the second or third trimester. Thirty-eight fetuses in study group were born with favorable outcomes after long-term follow-up. A total of 13.16% (5/38) remain mild narrow aorta and 3 of them showed smaller left ventricle after 3 years follow up. Prenatal AODz-score in infants remains mild narrow aorta after 2 years aged was higher than ones' aorta return to normal (P = .01), especially when AODz-score >1.725. Moreover, when prenatal ratio of AOIsD/left subclavian artery was <1.12, it was more likely that the aorta would remain mildly narrow at age 2.

CONCLUSION

Fetuses diagnosed with PLSVC with mild narrow aorta had favorable prognosis. AODz-score and AOIsD/left subclavian artery may be two predictors that reveal the risk of a mildly narrowed aorta remaining after birth.

Fetal Cardiac MRI Using Doppler US Gating: Emerging Technology and Clinical Implications

Fetal cardiac MRI using Doppler US gating is an emerging technique to support prenatal diagnosis of congenital heart disease and other cardiovascular abnormalities. Analogous to postnatal electrocardiographically gated cardiac MRI, this technique enables directly gated MRI of the fetal heart throughout the cardiac cycle, allowing for immediate data reconstruction and review of image quality. This review outlines the technical principles and challenges of cardiac MRI with Doppler US gating, such as loss of gating signal due to fetal movement. A practical workflow of patient preparation for the use of Doppler US-gated fetal cardiac MRI in clinical routine is provided. Currently applied MRI sequences (ie, cine or four-dimensional flow imaging), with special consideration of technical adaptations to the fetal heart, are summarized. The authors provide a literature review on the clinical benefits of Doppler US-gated fetal cardiac MRI for gaining additional diagnostic information on cardiovascular malformations and fetal hemodynamics. Finally, future perspectives of Doppler US-gated fetal cardiac MRI and further technical developments to reduce acquisition times and eliminate sources of artifacts are discussed. Keywords: MR Fetal, Ultrasound Doppler, Cardiac, Heart, Congenital, Obstetrics, Fetus Supplemental material is available for this article. © RSNA, 2024.

In-Depth Genomic Analysis: The New Challenge in Congenital Heart Disease

The use of next-generation sequencing has provided new insights into the causes and mechanisms of congenital heart disease (CHD). Examinations of the whole exome sequence have detected detrimental gene variations modifying single or contiguous nucleotides, which are characterised as pathogenic based on statistical assessments of families and correlations with congenital heart disease, elevated expression during heart development, and reductions in harmful protein-coding mutations in the general population. Patients with CHD and extracardiac abnormalities are enriched for gene classes meeting these criteria, supporting a common set of pathways in the organogenesis of CHDs. Single-cell transcriptomics data have revealed the expression of genes associated with CHD in specific cell types, and emerging evidence suggests that genetic mutations disrupt multicellular genes essential for cardiogenesis. Metrics and units are being tracked in whole-genome sequencing studies.

Evaluation of Fetal Cardiac Output and Modified Myocardial Performance Index in Pregnant Women with Idiopathic Polyhydramnios: A Case Control Study from a Tertiary Hospital

PURPOSE

This study aimed to investigate fetal cardiac output and myocardial performance index in pregnant women with idiopathic polyhydramnios and compare them to healthy pregnant women.

METHODS

Thirty patients admitted to Ankara City Hospital at 24-39 weeks of gestation with idiopathic polyhydramnios were included as the study group. Clinical characteristics, fetal cardiac output, and fetal modified myocardial performance index (Mod-MPI) were compared between the groups.

RESULTS

The combined cardiac output (CCO), left cardiac output (LCO), right cardiac output (RCO), pulmonary artery velocity time integral (PA-VTI), and aortic VTI were statistically significantly higher in the study group (p=0.003, p=0.028, p=0.002, p=0.000, and p=0.017, respectively).The idiopathic polyhydramnios group had a significantly higher Mod-MPI and isovolumetric contraction time (ICT) and a significantly lower ejection time (ET) compared to the controls (p=000, p=0.003, and p=0.023, respectively). In the idiopathic polyhydramnios group, the aortic max (p=0.009) and aortic VTI (p=0.047) values were significantly lower and the left ventricular outflow tract isovolumetric relaxation time (LVOT-IRT) (p=0.021) was significantly higher in cases where the NICU was required. According to the ROC analysis performed in the idiopathic polyhydramnios group, the optimal cut-off values of aortic max, aortic VTI, and LVOT-IRT in the prediction of the NICU requirement were (57.5, 0.089 and 41.5, respective cut-off value) (p=0.010, p=0.048, p=0.021, respectively).

CONCLUSIONS

Both fetal cardiac output and Mod-MPI values were altered in fetuses with idiopathic polyhydramnios.

Risk factor analysis for adverse prognosis of the fetal ventricular septal defect (VSD)

BACKGROUND

Ventricular septal defect (VSD) is the most common subtype of congenital heart disease. In the present study, we aimed to determine whether chromosome aberration was associated with the occurrence of VSD and evaluate the association of VSD size, location and chromosome aberration with adverse outcomes in the Chinese fetuses.

METHODS

Fetuses with VSD and comprehensive follow-up data were included and evaluated retrospectively. Medical records were used to collect epidemiological data and foetal outcomes. For VSD fetuses, conventional karyotype and microarray analysis were conducted. After adjusting confounding factors by using multivariable logistic regression analyses, the association between chromosome variations and VSD occurrence was explored. The association between defect size, location and chromosome aberrations and adverse foetal outcomes was also investigated.

RESULTS

Chromosome aberration was the risk factor for VSD occurrence, raising 6.5-fold chance of developing VSD. Chromosome aberration, peri-membranous site and large defect size of VSD were significant risk factors of adverse fetal outcome. Chromosome aberrations, including pathogenic copy number variations (CNVs) and variations of uncertain significance (VUS), were both risk factors, increasing the risk of the adverse fetal outcome by 55.9 times and 6.7 times, respectively. The peri-membranous site would increase 5.3-fold risk and defects larger than 5 mm would increase the 7.1-fold risk for poor fetal outcome.

CONCLUSIONS

The current investigation revealed that chromosomal abnormalities, large defects, and the peri-membranous site were all risk factors for poor fetal outcomes. Our study also indicated that chromosome aberration was one of risk factors for the VSD occurrence.

Current status and challenges in prenatal and neonatal screening, diagnosis, and management of congenital heart disease in China

Congenital heart disease (CHD), a wide spectrum of diseases with varied outcomes, is the most common congenital malformation worldwide. In this Series of three papers, we describe the burden of CHD in China; the development of screening, diagnosis, treatment, and follow-up strategies; and challenges associated with the disease. We also propose solutions and recommendations for policies and actions to improve the outcomes of CHD. In the first paper in this Series, we focus on prenatal and neonatal screening, diagnosis, and management of CHD. Based on advanced international knowledge, the Chinese Government has developed a network system comprising prenatal screening, diagnosis of CHD subtypes, specialist consultation appointments, and treatment centres for CHD. A new professional discipline, fetal cardiology, has been formed and rapidly developed. Consequently, the overall coverage of prenatal and neonatal screening and the accuracy of CHD diagnoses have gradually improved, and the neonatal CHD mortality rate has decreased substantially. However, China still faces several challenges in the prevention and treatment of CHD, such as insufficient diagnostic capabilities and unqualified consultation services in some regions and rural areas. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Comparison of the left and right ventricular size and systolic function of low-risk fetuses in the third trimester: Which is more dominant?

Objective

To quantify fetal cardiovascular parameters utilizing fetal-specific 2D speckle tracking technique and to explore the differences in size and systolic function of the left and right ventricles in low-risk pregnancy.

Methods

A prospective cohort study was performed in 453 low-risk single fetuses (28+0–39+6 weeks) to evaluate ventricular size [i.e., end-diastolic length (EDL), end-systolic length (ESL), end-diastolic diameter (ED), end-systolic diameter (ES), end-diastolic area, end-systolic area, end-diastolic volume (EDV), and end-systolic volume (ESV)] and systolic function [i.e., ejection fraction (EF), stroke volume (SV), cardiac output (CO), cardiac output per kilogram (CO/KG), and stroke volume per kilogram (SV/KG)].

Results

This study showed that (1) the reproducibility of the interobserver and intraobserver measurements was good to excellent (ICC 0.626–0.936); (2) with advancing gestation, fetal ventricular size and systolic function increased, whereas right ventricular (RV) EF decreased and left ventricular (LV) EF was not significantly changed; (3) LV length was longer than RV length in diastole (2.24 vs. 1.96 cm, P &lt; 0.001) and systole (1.72 vs. 1.52 cm, P &lt; 0.001); (4) LV ED-S1 and ES-S1 were shorter than the RV ED-S1 and ES-S1 (12.87 vs. 13.43 mm, P &lt; 0.001; 5.09 vs. 5.61 mm, P &lt; 0.001); (5) there were no differences between the LV and RV in EDA or EDV; (6) the mean EDV ratio of right-to-left ventricle was 1.076 (95% CI, 1.038–1.114), and the mean ESV ratio was 1.628 (95% CI, 1.555–1.701); (7) the EF, CO and SV of the LV were greater than the RV (EF: 62.69% vs. 46.09%, P &lt; 0.001; CO: 167.85 vs. 128.69 ml, P &lt; 0.001; SV: 1.18 vs. 0.88 ml, P &lt; 0.001); (8) SV and CO increased with ED-S1 and EDL, but EF was not significantly changed.

Conclusion

Low-risk fetal cardiovascular physiology is characterized by a larger RV volume (especially after 32 weeks) and greater LV outputs (EF, CO, SV, SV/KG and CO/KG).

Fetal Cardiac Cine MRI with Doppler US Gating in Complex Congenital Heart Disease

Purpose

To apply Doppler US (DUS)-gated fetal cardiac cine MRI in clinical routine and investigate diagnostic performance in complex congenital heart disease (CHD) compared with that of fetal echocardiography.

Materials and Methods

In this prospective study (May 2021 to March 2022), women with fetuses with CHD underwent fetal echocardiography and DUS-gated fetal cardiac MRI on the same day. For MRI, balanced steady-state free precession cine images were acquired in the axial and optional sagittal and/or coronal orientations. Overall image quality was assessed on a four-point Likert scale (from 1 = nondiagnostic to 4 = good image quality). The presence of abnormalities in 20 fetal cardiovascular features was independently assessed by using both modalities. The reference standard was postnatal examination results. Differences in sensitivities and specificities were determined by using a random-effects model.

Results

The study included 23 participants (mean age, 32 years ± 5 [SD]; mean gestational age, 36 weeks ± 1). Fetal cardiac MRI was completed in all participants. The median overall image quality of DUS-gated cine images was 3 (IQR, 2.5-4). In 21 of 23 participants (91%), underlying CHD was correctly assessed by using fetal cardiac MRI. In one case, the correct diagnosis was made by using MRI only (situs inversus and congenitally corrected transposition of the great arteries). Sensitivities (91.8% [95% CI: 85.7, 95.1] vs 93.6% [95% CI: 88.8, 96.2]; P = .53) and specificities (99.9% [95% CI: 99.2, 100] vs 99.9% [95% CI: 99.5, 100]; P > .99) for the detection of abnormal cardiovascular features were comparable between MRI and echocardiography, respectively.

Conclusion

Using DUS-gated fetal cine cardiac MRI resulted in performance comparable with that of using fetal echocardiography for diagnosing complex fetal CHD.Keywords: Pediatrics, MR-Fetal (Fetal MRI), Cardiac, Heart, Congenital, Fetal Imaging, Cardiac MRI, Prenatal, Congenital Heart DiseaseClinical trial registration no. NCT05066399 Supplemental material is available for this article. © RSNA, 2023See also the commentary by Biko and Fogel in this issue.

Learning deep architectures for the interpretation of first-trimester fetal echocardiography (LIFE) - a study protocol for developing an automated intelligent decision support system for early fetal echocardiography

BACKGROUND

Congenital Heart Disease represents the most frequent fetal malformation. The lack of prenatal identification of congenital heart defects can have adverse consequences for the neonate, while a correct prenatal diagnosis of specific cardiac anomalies improves neonatal care neurologic and surgery outcomes. Sonographers perform prenatal diagnosis manually during the first or second-trimester scan, but the reported detection rates are low. This project's primary objective is to develop an Intelligent Decision Support System that uses two-dimensional video files of cardiac sweeps obtained during the standard first-trimester fetal echocardiography (FE) to signal the presence/absence of previously learned key features.

METHODS

The cross-sectional study will be divided into a training part of the machine learning approaches and the testing phase on previously unseen frames and eventually on actual video scans. Pregnant women in their 12-13 + 6 weeks of gestation admitted for routine first-trimester anomaly scan will be consecutively included in a two-year study, depending on the availability of the experienced sonographers in early fetal cardiac imaging involved in this research. The Data Science / IT department (DSIT) will process the key planes identified by the sonographers in the two- dimensional heart cine loop sweeps: four-chamber view, left and right ventricular outflow tracts, three vessels, and trachea view. The frames will be grouped into the classes representing the plane views, and then different state-of-the- art deep-learning (DL) pre-trained algorithms will be tested on the data set. The sonographers will validate all the intermediary findings at the frame level and the meaningfulness of the video labeling.

DISCUSSION

FE is feasible and efficient during the first trimester. Still, the continuous training process is impaired by the lack of specialists or their limited availability. Therefore, in our study design, the sonographer benefits from a second opinion provided by the developed software, which may be very helpful, especially if a more experienced colleague is unavailable. In addition, the software may be implemented on the ultrasound device so that the process could take place during the live examination.

TRIAL REGISTRATION

The study is registered under the name "Learning deep architectures for the Interpretation of Fetal Echocardiography (LIFE)", project number 408PED/2020, project code PN-III-P2-2.1-PED-2019.

TRIAL REGISTRATION

ClinicalTrials.gov , unique identifying number NCT05090306, date of registration 30.10.2020.

Evaluation of the trachea in fetuses with double aortic arch using prenatal ultrasound: a retrospective cohort study

BACKGROUND

Double aortic arch is the most common form of complete vascular ring. The trachea and/or esophagus could be compressed by the complete vascular ring, which may lead to early respiratory and/or esophageal symptoms in children with double aortic arch. Accurate prenatal assessment of tracheal compression could provide relevant information for perinatal clinical management of double aortic arch and emergency treatment of infants with double aortic arch. The fetal trachea is filled with amniotic fluid and can be clearly visualized with prenatal ultrasound. Previous studies reported the use of prenatal ultrasound to measure the tracheal internal diameters in normal fetuses and showed a linear correlation between the fetal tracheal internal diameters and gestational age. However, to the best of our knowledge, few studies have quantitatively evaluated tracheal compression in fetuses with double aortic arch using ultrasound.

OBJECTIVE

This study aimed to evaluate the tracheal compression caused by the vascular ring in fetuses with double aortic arch using prenatal ultrasound and to analyze the relationship between tracheal compression and postnatal clinical symptoms.

STUDY DESIGN

The data of fetuses with double aortic arch diagnosed with prenatal ultrasound at 2 institutions from January 2011 to April 2021 were retrospectively analyzed. Singleton pregnancies with normal fetuses as the control group were prospectively recruited. The tracheal compression-evaluated by comparing the tracheal internal diameter z scores against the gestational age-was assessed in fetuses with double aortic arch and in normal fetuses. The live-born infants with double aortic arch were divided into symptomatic and asymptomatic groups for the comparison of z scores. The receiver operating characteristic curve for the tracheal internal diameter z score cutoffs and prediction of symptomatic infants with double aortic arch was plotted. Intraobserver and interobserver agreements were investigated.

RESULTS

A total of 26 fetuses with double aortic arch were diagnosed, and 14 fetuses (53.8%) with double aortic arch were delivered alive. Among the 14 live-born infants, 7 (50.0%) were symptomatic, whereas 7 (50.0%) were asymptomatic. The tracheal internal diameter z scores were significantly lower in the double aortic arch group than in the normal groups (-0.62±1.36 vs 0.00±0.78; P<.001). The tracheal internal diameter z scores were significantly lower in the symptomatic group than in the asymptomatic group (-1.42±0.92 vs -0.49±0.96; P=.018). The area under the curve was 0.878 (95% confidence interval, 0.689-1.000). Using a tracheal internal diameter z scores cutoff of -1.21, the sensitivity was 71%, and the specificity was close to 100%. The intraclass correlation coefficients of interobserver and intraobserver agreements were 0.987 (95% confidence interval, 0.980-0.992) and 0.975 (95% confidence interval, 0.955-0.987), respectively.

CONCLUSION

The clinical symptoms in infants with double aortic arch were associated with prenatal tracheal compression, which can be prenatally evaluated using ultrasound. If fetuses are diagnosed with double aortic arch, prenatal surveillance of the tracheal internal diameters and comparison with z score reference ranges could provide pertinent information that would aid perinatal clinical management.

Cord blood cardiovascular biomarkers in tetralogy of fallot and D-transposition of great arteries

Previous reports suggest that cord blood biomarkers could serve as a prognostic tool for conotruncal congenital heart defects (CHD). We aimed to describe the cord blood profile of different cardiovascular biomarkers in a prospective series of fetuses with tetralogy of Fallot (ToF) and D-transposition of great arteries (D-TGA) and to explore their correlation with fetal echocardiography and perinatal outcome.

Methods

A prospective cohort study (2014-2019), including fetuses with isolated ToF and D-TGA and healthy controls, was conducted at two tertiary referral centers for CHD in Barcelona. Obstetric ultrasound and fetal echocardiography were performed in the third trimester and cord blood was obtained at delivery. Cord blood concentrations of N-terminal precursor of B-type natriuretic peptide, Troponin I, transforming growth factorβ (TGFβ), placental growth factor, and soluble fms-like tyrosine kinase-1 were determined.

Results

Thirty-four fetuses with conotruncal-CHD (22 ToF and 12 D-TGA) and 36 controls were included. ToF-fetuses showed markedly increased cord blood TGFβ (24.9 ng/ml (15.6-45.3) vs. normal heart 15.7 ng/ml (7.2-24.3) vs. D-TGA 12.6 ng/ml (8.7-37.9); P = 0.012). These results remained statistically significant even after adjusting for maternal body mass index, birth weight and mode of delivery. TGFß levels showed a negative correlation with the pulmonary valve diameter z-score at fetal echocardiography (r = -0.576, P = 0.039). No other differences were found in the rest of cord blood biomarkers among the study populations. Likewise, no other significant correlations were identified between cardiovascular biomarkers, fetal echocardiography and perinatal outcome.

Conclusions

This study newly describes increased cord blood TGFβ concentrations in ToF compared to D-TGA and normal fetuses. We also demonstrate that TGFβ levels correlate with the severity of right ventricle outflow obstruction. These novel findings open a window of research opportunities on new prognostic and potential preventive strategies.

Fetal intelligent navigation echocardiography (FINE) has superior performance compared to manual navigation of the fetal heart by non-expert sonologists

OBJECTIVES

Manual and intelligent navigation (i.e. fetal intelligent navigation echocardiography or FINE) by the operator are two methods to obtain standard fetal cardiac views from spatiotemporal image correlation (STIC) volumes. The objective was to compare the performance between manual and intelligent navigation (FINE) of the fetal heart by non-expert sonologists.

METHODS

In this prospective observational study, ten sonologists underwent formal training on both navigational methods. Subsequently, they were tested on their ability to obtain nine cardiac views from five STIC volumes of normal fetal hearts (19-28 gestational weeks) using such methods. The following parameters were determined for both methods: (1) success rate of obtaining nine cardiac views; (2) mean time to obtain nine cardiac views per sonologist; and (3) maximum number of cardiac views successfully obtained for each STIC volume.

RESULTS

All fetal cardiac images obtained from 100 STIC volumes (50 for each navigational method) were reviewed by an expert in fetal echocardiography. Compared to manual navigation, FINE was associated with a significantly: (1) higher success rate of obtaining eight (excluding the abdomen view) appropriate cardiac views (92-100% vs. 56-88%; all p<0.05); (2) shorter mean time (minute:seconds) to obtain nine cardiac views (2:11 ± 0:37 vs. 15:49 ± 7:44; p<0.0001); and (3) higher success rate of obtaining all nine cardiac views for a given STIC volume (86 vs. 14%; p<0.001).

CONCLUSIONS

When performed by non-expert sonologists, intelligent navigation (FINE) had a superior performance compared to manual navigation of the normal fetal heart. Specifically, FINE obtained appropriate fetal cardiac views in 92-100% of cases.

Preliminary study on the evaluation of mitral annulus displacement in normal fetuses by automated cardiac motion quantitation

OBJECTIVES

The aim of this study was to assess the characteristics of mitral annular plane systolic excursion (MAPSE) in different longitudinal directions in normal fetuses using a new method, automatic cardiac motion quantification (aCMQ).

METHODS

A cross-sectional study was conducted in 164 fetuses with structurally normal hearts. The time-displacement curves of the septal mitral annulus (SMA) in three directions, including point A, B and C (MAPSE-SMA-A, MAPSE-SMA-B, MAPSE-SMA-C), were recorded by aCMQ. The time to peak (TTP) in three directions, including point A, B and C (TTP-SMA-A, TTP-SMA-B, TTP-SMA-C) were recorded. In the same way, various parameters of the lateral mitral annulus (LMA) were obtained including MAPSE-LMA-A, MAPSE-LMA-B, MAPSE-LMA-C, TTP-LMA-A, TTP-LMA-B and TTP-LMA-C. Free angle M-mode echocardiography (FAM) was used to obtain MAPSE of LMA (FAM-MAPSE). Finally, all the data were analyzed statistically.

RESULTS

MAPSE was positively correlated with gestational age, and the difference between the second- and third-trimester groups was statistically significant. MAPSE-LMA in point B and C were greater than those of SMA. MAPSE-LMA-C and MAPSE-SMA-A were the largest in three directions.The difference between point B and C were statistically significant (p < .05), with no significant difference at point A (p > .05). There was no significant difference found in all TTP (all p > .05). The MAPSE-LMA-C was less than the FAM-MAPSE, and the differences were found significantly (p < .05), but there was better correlation (p < .05).

CONCLUSIONS

The longitudinal movement of the fetal mitral annulus is comprehensive, with multiple directions and different displacements. Perpendicular to the mitral annulus is the maximum displacement. It is positively related to the gestational age. From the second trimester, the longitudinal contraction of the left ventricle wall has good synchronization. It possesses clinical value in selecting different methods and parameters during evaluating left ventricular function.

The assessment of fetal cardiac output in maternal hypothyroidism under levothyroxine treatment

OBJECTIVE

In this study, we investigated whether maternal hypothyroidism has a role in the cardiac output (CO) of the fetus or not.

METHODS

Pregnant women between 33 and 37 gestational weeks known to have hypothyroidism and using levothyroxine were accepted as the case group. Gestational age-matched healthy euthyroid pregnant women constituted the control group. Fetal echocardiography was performed. Diameters and the velocity waveform of the pulmonary artery (PA) and aortic valves were measured. Velocity time integral (VTI) was also measured from the ventricular outflow tract. CO was calculated using VTI × π (Aortic Valve or Pulmonary Valve diameter/2) 2 × heart rate formula.

RESULTS

The aortic and PA annulus were measured larger in the control group. (p = .003, p = .005, respectively). Furthermore, the right and left CO of the case group were lower than the control group. Whereas the mean combined CO (ml/min) of the case group was 674.8 ± 146.2, it was 827.8 ± 167.9 in the control group (p < .001). Additionally, a negative correlation was observed between thyroid-stimulating hormone and aortic VTI (r:-.480; p:.006).

CONCLUSION

The findings of our study suggest that the CO of the fetus may be affected by maternal hypothyroidism.

Practice variations for fetal and neonatal congenital heart disease within the Children's Hospitals Neonatal Consortium

BACKGROUND

Many aspects of care for fetuses and neonates with congenital heart disease (CHD) fall outside standard practice guidelines, leading to the potential for significant variation in clinical care for this vulnerable population.

METHODS

We conducted a cross-sectional survey of site sponsors of the Children's Hospitals Neonatal Consortium, a multicenter collaborative of 41 Level IV neonatal intensive care units to assess key areas of clinical practice variability for patients with fetal and neonatal CHD.

RESULTS

We received responses from 31 centers. Fetal consult services are shared by neonatology and pediatric cardiology at 70% of centers. Three centers (10%) routinely perform fetal magnetic resonance imaging (MRI) for women with pregnancies complicated by fetal CHD. Genetic testing for CHD patients is routine at 76% of centers. Preoperative brain MRI is standard practice at 5 centers (17%), while cerebral NIRS monitoring is regularly used at 14 centers (48%). Use of electroencephalogram (EEG) after major cardiac surgery is routine in 5 centers (17%). Neurodevelopmental follow-up programs are offered at 30 centers (97%).

CONCLUSIONS

Many aspects of fetal and neonatal CHD care are highly variable with evolving shared multidisciplinary models.

IMPACT

Many aspects of fetal and neonatal CHD care are highly variable. Genetic testing, placental examination, preoperative neuroimaging, and postoperative EEG monitoring carry a high yield of finding abnormalities in patients with CHD and these tests may contribute to more precise prognostication and improve care. Evidence-based standards for prenatal and postnatal CHD care may decrease inter-center variability.

The Application of Knowledge Distillation toward Fine-Grained Segmentation for Three-Vessel View of Fetal Heart Ultrasound Images

Objectives. Measuring anatomical parameters in fetal heart ultrasound images is crucial for the diagnosis of congenital heart disease (CHD), which is highly dependent on the clinical experience of the sonographer. To address this challenge, we propose an automated segmentation method using the channel-wise knowledge distillation technique. Methods. We design a teacher-student architecture to conduct channel-wise knowledge distillation. ROI-based cropped images and full-size images are used for the teacher and student models, respectively. It allows the student model to have both the fine-grained segmentation capability inherited from the teacher model and the ability to handle full-size test images. A total of 1,300 fetal heart ultrasound images of three-vessel view were collected and annotated by experienced doctors for training, validation, and testing. Results. We use three evaluation protocols to quantitatively evaluate the segmentation accuracy: Intersection over Union (IoU), Pixel Accuracy (PA), and Dice coefficient (Dice). We achieved better results than related methods on all evaluation metrics. In comparison with DeepLabv3+, the proposed method gets more accurate segmentation boundaries and has performance gains of 1.8% on mean IoU (66.8% to 68.6%), 2.2% on mean PA (79.2% to 81.4%), and 1.2% on mean Dice (80.1% to 81.3%). Conclusions. Our segmentation method could identify the anatomical structure in three-vessel view of fetal heart ultrasound images. Both quantitative and visual analyses show that the proposed method significantly outperforms the related methods in terms of segmentation results.

Decreased fetal cardiac output in pregnant women with severe SARS-Cov-2 infection

AIM

We aimed to examine fetal cardiac output (CO) in patients who recovered from severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection.

MATERIALS

This prospective study included 48 pregnant women recovered from SARS-CoV-2 infection and 50 control cases. SARS-CoV-2 infection was diagnosed by polymerase chain reaction (PCR) test in patients. Fetal echocardiographic evaluations were performed at 24-37 weeks of gestation in pregnant women who recovered from the infection and control group.

RESULTS

The median value of ultrasound evaluation was 34 (2.6) weeks of gestation in the recovery from the SARS-CoV-2 infection (RSI) group, and 32 (7.6) weeks in the control group (p = .565). Left cardiac output (LCO) z score was significantly lower in the RSI group than the control group (p = .041). LCO and combine cardiac output (CCO) z score were significantly lower in the severe disease group than mild, moderate disease groups, and controls (p = .019 and p = .013). CCO (ml/min/kg) was decreased in the severe disease group when compared with control and mild disease groups (p = .044).

CONCLUSION

In the present study, fetal cardiac output in pregnant women who recovered from SARS-CoV-2 infection was found to be significantly reduced in those with severe disease, while there was no significant difference in mild and moderate cases. Placental dysfunction and inflammatory cytokines might cause fetal cardiac changes. Further studies could be clarified on the impact of SARS-CoV-2 infection on fetal cardiac function.

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.

Echocardiographic evaluation in Dorper ovine fetuses: Applications and limitations

In this study we aim to show the application of ultrasound evaluation of the fetal heart in the ovine species, as well as its limitations in the field. Ten Dorper sheep, without any sedation, were evaluated starting from the second month of pregnancy through transabdominal ultrasound with an ultrasound device equipped with a convex transducer. Images of the fetal heart were obtained through maternal abdominal ultrasound by identifying the position of the fetus and conducting the following measurements: length and diameter of the heart, dimensions of the right and left ventricles and dimensions of the right and left atria. The measurements could only be conducted with acceptable precision starting from the third month of pregnancy. There was a significant difference only for left ventricle diameter, which was larger in the fifth month of pregnancy. The echocardiographic evaluation of the fetus enables monitoring the heart development identifying early fetal viability, assessing inadequate events that could put the pregnancy at risk, especially for production animals. For the experimental design of research employing production animals, it is important to consider, among other factors, the limitations of the evaluation on the field, such as restraining the animals, the stress caused by handling and environmental conditions, temperature, luminosity, facilities available and the qualifications of the team.

Prenatal diagnosis of transposition of the great arteries: an updated review

Simple transposition of the great arteries (TGA) is a cyanotic heart disease that accounts for 5% to 7% of all congenital heart diseases. It is commonly underdiagnosed in utero, with prenatal detection rates of less than 50%. Simple TGA is characterized by ventriculoarterial discordance, atrioventricular concordance, and a parallel relationship of TGA. The prenatal diagnosis of TGA influences postnatal outcomes and therefore requires planned delivery and perinatal management. For these reasons, it is important to identify the key ultrasound markers of TGA to improve the prenatal diagnosis and consequently provide perinatal assistance. The presence of two vessels instead of three in the three-vessel tracheal view, a parallel course of TGA, and identification of the origin of each of TGA are the key markers for diagnosing TGA. In addition to the classical ultrasound signs, other two-dimensional ultrasound markers such as an abnormal right convexity of the aorta, an I-shaped aorta, and the "boomerang sign" may also be used to diagnose TGA in the prenatal period. When accessible, an automatic approach using four-dimensional technologies such as spatio-temporal image correlation and sonographically-based volume computer-aided analysis may improve the prenatal diagnosis of TGA. This study aimed to review the ultrasound markers that can be used in the antenatal diagnosis of TGA, with a focus on the tools used by ultrasonographers, the obstetric and fetal medicine team, and perinatal cardiologists to improve the diagnosis of this condition.

The construction and application of an ultrasound and anatomical cross-sectional database of structural malformations of the fetal heart

OBJECTIVES

Establish a fetal heart anatomical cross-sectional database that correlates with screening transverse ultrasound images suggested by international professional organizations to detect congenital heart defects.

METHODS

Fetuses with suspected congenital heart defects identified using the following cardiac image sequences obtained from transverse slices beginning from the upper abdomen and ending in the upper thorax were the subjects of this study: (1) four-chamber view, (2) left ventricular outflow tract view, (3) three-vessel right ventricular outflow tract view, and (4) the three-vessel tracheal view. A database of digital two-dimensional images of the transverse sweep was created for fetuses with confirmed congenital heart defects. In addition, using four-dimensional ultrasound spatial-temporal image correlation, selected transverse ultrasound images were acquired as part of the database. Ultrasound-detected congenital heart defects were confirmed postnatally from pathological specimens of the heart and lungs using a cross-sectional technique that mirrored the ultrasound images described above. When anatomical specimens were not available, prenatal ultrasound-detected congenital heart defects were confirmed using postnatal echocardiography and/or following surgery.

RESULTS

The four screening views described in the Methods section identified 160 fetuses that comprised the database. Forty-five datasets consisted of both ultrasound and anatomical cross-sectional images. Thirteen percent (6/45) only had abnormalities of the four-chamber view (eg, endocardial cushion defects). Twenty-four percent (11/45) had abnormalities of the four-chamber view as well as right and left outflow tracts (eg, complex malformations). Of these, 10 of 11 had an abnormal tracheal view. Sixteen percent (7/45) had an abnormal four-chamber view and abnormal right outflow tract (eg, pulmonary stenosis). Thirty-three percent (15/45) had a normal four-chamber view but had abnormal right and left outflow tracts as well as an abnormal tracheal view (eg, tetralogy of Fallot, D-transposition of the great arteries).

CONCLUSIONS

Combining both ultrasound and anatomical imaging may be of assistance in training imagers to recognize cardiovascular pathology when performing the screening examination of the fetal heart.

Risk of Stillbirth for Fetuses With Specific Birth Defects

OBJECTIVE

To estimate the risk of stillbirth (fetal death at 20 weeks of gestation or more) associated with specific birth defects.

METHODS

We identified a population-based retrospective cohort of neonates and fetuses with selected major birth defects and without known or strongly suspected chromosomal or single-gene disorders from active birth defects surveillance programs in nine states. Abstracted medical records were reviewed by clinical geneticists to confirm and classify all birth defects and birth defect patterns. We estimated risks of stillbirth specific to birth defects among pregnancies overall and among those with isolated birth defects; potential bias owing to elective termination was quantified.

RESULTS

Of 19,170 eligible neonates and fetuses with birth defects, 17,224 were liveborn, 852 stillborn, and 672 electively terminated. Overall, stillbirth risks ranged from 11 per 1,000 fetuses with bladder exstrophy (95% CI 0-57) to 490 per 1,000 fetuses with limb-body-wall complex (95% CI 368-623). Among those with isolated birth defects not affecting major vital organs, elevated risks (per 1,000 fetuses) were observed for cleft lip with cleft palate (10; 95% CI 7-15), transverse limb deficiencies (26; 95% CI 16-39), longitudinal limb deficiencies (11; 95% CI 3-28), and limb defects due to amniotic bands (110; 95% CI 68-171). Quantified bias analysis suggests that failure to account for terminations may lead to up to fourfold underestimation of the observed risks of stillbirth for sacral agenesis (13/1,000; 95% CI 2-47), isolated spina bifida (24/1,000; 95% CI 17-34), and holoprosencephaly (30/1,000; 95% CI 10-68).

CONCLUSION

Birth defect-specific stillbirth risk was high compared with the U.S. stillbirth risk (6/1,000 fetuses), even for isolated cases of oral clefts and limb defects; elective termination may appreciably bias some estimates. These data can inform clinical care and counseling after prenatal diagnosis.

Novel foetal echocardiographic image processing software (5D Heart) improves the display of key diagnostic elements in foetal echocardiography

Background

To evaluate the clinical value of foetal intelligent navigation echocardiography (5D Heart) for the display of key diagnostic elements in basic sections.

Methods

3D volume datasets of 182 normal singleton foetuses were acquired with a four chamber view by using a volume probe. After processing the datasets by using 5D Heart, eight cardiac diagnostic planes were demonstrated, and the image qualities of the key diagnostic elements were graded by 3 doctors with different experiences in performing foetal echocardiography.

Results

A total of 231 volume datasets acquired from the 182 normal foetuses were used for 5D Heart analysis and display. The success rate of 8 standard diagnostic views was 88.2%, and the success rate of each diagnostic view was 55.8–99.2% and 70.7–99.0% for the random four chamber view as the initial section and for the apical four chamber view as the initial section, respectively. The success rate of each diagnostic element in the 8 diagnostic sections obtained by 5D Heart was 58.9%~ 100%. Excellent agreement was found between experienced sonographers and less-experienced sonographers (kappa> 0.769). Inter- and intra-observer agreement were substantial to near-perfect, kappa values ranging from 0.612 to 1.000 (Cohen’s kappa).

Conclusions

5D Heart can significantly improve the image quality of key diagnostic elements in foetal echocardiography with low operator dependency and good reproducibility.

Detailed Echocardiographic Measurements of Individual Chamber in a Chinese Cohort of Hypoplastic Left Heart Syndrome and Comparison with Normal Fetuses via Z-score Modeling

Hypoplastic left heart syndrome (HLHS) is a rare, but exceptionally serious, congenital heart defect. We aimed to explore the best-fitted Z-score models for individual chamber dimension and to draw a comparison between fetuses with HLHS and the normal Chinese cohort. We made measurements of 1674 healthy fetuses and 79 fetuses with HLHS, undertaking echocardiography. Normal fetal cardiovascular Z-score formulae were established by curve-fitting with 5 algorithmic functions and weighted regression of absolute residuals. Classic linear models were fitted for left ventricular diameter against gestational age, and log-transformed linear-power models-were statistically better for left ventricular length, diameter of left atrium and ascending aorta. Fetuses with HLHS manifested significantly lower Z-score means (≤3.5) for these 4 parameters and the vast majority (∼90%) lay beyond -2. Overall, cardiovascular Z-score equations were reliably constructed in a larger Chinese cohort, and their application should benefit evaluation and diagnosis of HLHS.

Behavior of fetal longitudinal myocardial fibers assessed by speckle tracking to obtain strain and strain rate values for low-risk pregnancies

Objective To analyze the behavior of fetal longitudinal myocardial fibers assessed by speckle tracking (STE) after fetal viability. Methods A cross-sectional study was performed in 156 women with normal singleton pregnancies from 22 to 31 weeks of gestation. Strain (S) and strain rate (SR) values were measured in both ventricles during the fetal cardiac cycle. The population was divided into five gestational age groups based on 2-week intervals. The correlations of maternal variables with the S and SR variables and intra-observer analysis were performed. Results There was a significant difference in the S and SR values of the left ventricle (LV) among the gestational age groups (P = 0.007). Significantly higher S and SR values were observed in early age groups demonstrating reductions in LV S and SR values at 26 weeks, followed by stabilization. For the right ventricle (RV), there was no significant difference between gestational age groups. Significant intra-observer agreement was observed for S values of the RV (P = 0.008) and LV (P = 0.0004) and SR values of the RV (P = 0.0001) and LV (P = 0.015). Conclusion Decreases in the S and SR values of the LV occurred after 26 weeks, followed by stabilization. No significant difference was observed in the S or SR value of the RV among the gestational age groups, and no significant association of any maternal variable evaluated with S and SR values was observed. Significant intra-observer agreement was obtained among the results.

Screening for congenital heart disease in a Singapore neonatal unit

INTRODUCTION

Congenital heart disease (CHD) is a leading cause of infant mortality. The aim of this study was to evaluate the efficacy of a neonatal screening programme for CHD before the introduction of pulse oximetry.

METHODS

This was a retrospective review of live births in the period 2003-2012. Cases of CHD were detected through prenatal ultrasonography and/or postnatal examination, and confirmed using two-dimensional echocardiography. Data was rigorously checked against multiple sources. The antenatal detection rate, sensitivity, specificity, predictive values and likelihood ratios of the screening programme were analysed for all cases of CHD and critical CHD.

RESULTS

The incidence of CHD was 9.7 per 1,000 live births. The commonest CHD was ventricular septal defect (54.8%). The antenatal detection rate was three times higher in the critical CHD group (64.0%) compared to the group as a whole (21.1%). The sensitivity and specificity of screening was 64.5% and 99.7% for all CHD, and 92.9% and 99.1% for the critical CHD group, respectively. The positive likelihood ratio was 215 and 103, while the negative likelihood ratio was 0.36 and 0.07 for all CHD and critical CHD, respectively.

CONCLUSION

The CHD screening programme had excellent specificity but limited sensitivity. The high positive likelihood ratios indicate that where sufficient risk factors for CHD are present, a positive result effectively confirms the presence of CHD. The low negative likelihood ratio for critical CHD indicates that, where prior suspicion for critical CHD is low, a negative result is reassuring.

Nomograms of Fetal Right Ventricular Fractional Area Change by 2D Echocardiography

OBJECTIVES

Fetal right ventricular (RV) function assessment is challenging due to the RV geometry and limitations of in utero assessment. Postnatally, 2D echocardiographic RV fractional area change (FAC) is used to assess RV global systolic function by calculating the percentage of change in RV area from systole to diastole. Reports on FAC are scarce in prenatal life, and nomograms throughout pregnancy are not available. Our aims were (1) to study prenatal RV FAC feasibility and reproducibility and (2) to construct nomograms for RV FAC and end-diastolic (ED) and end-systolic (ES) RV areas from 18 to 41 weeks of gestation.

METHODS

Prospective cohort study including 602 low-risk singleton pregnancies undergoing a fetal echocardiography from 18 to 41 weeks of gestation. RV ED and ES areas were measured following standard recommendations for ventricular dimensions and establishing strict landmarks to identify the different phases of the cardiac cycle. RV FAC was calculated as: ([ED area - ES area]/ED area) × 100. RV FAC intra- and inter-observer reproducibility was evaluated in 45 fetuses by calculating the intraclass correlation coefficient (ICC). Parametric regressions were tested to model each parameter against gestational age (GA) and estimated fetal weight (EFW).

RESULTS

RV areas and FAC were successfully obtained in ∼99% of fetuses with acceptable reproducibility throughout gestation (RV ED area inter-observer ICC [95% CI] 0.96 [0.93-0.98], RV ES area 0.97 [0.94-0.98], and FAC 0.69 [0.44-0.83]). Nomograms were constructed for RV ED and ES areas and FAC. RV areas showed a quadratic and logarithmic increase with GA and EFW, respectively. In contrast, RV FAC showed a slight quadratic decrease throughout gestation (mean RV FAC ranged from 36% at 18 weeks of gestation [10-90th centiles: 25-47%, respectively] to 29% at 41 weeks [10-90th centiles: 18-40%, respectively]). The best models for RV areas and FAC were a second-degree polynomial.

CONCLUSIONS

RV FAC is a feasible and reproducible parameter to assess RV global systolic function in fetal life. We provide reference ranges adjusted by GA and EFW that can be used as normal references for the assessment of RV function in prenatal conditions.

Screening performance of congenital heart defects in first trimester using simple cardiac scan, nuchal translucency, abnormal ductus venosus blood flow and tricuspid regurgitation

OBJECTIVE

The objective of this study was to analyze if the addition of simple cardiac scan in cases with increased nuchal translucency (NT) and/or abnormal ductus venosus (DV) blood flow, and/or tricuspid regurgitation (TCR) can improve detection of congenital heart defects (CHD) in chromosomally normal fetuses without non-cardiac defects at 11-13 + 6 gestational weeks in a population of singleton pregnancies.

METHODS

During the 10 years period, all singleton pregnancies at 11-13 + 6 weeks were routinely scanned for NT, DV blood flow and TCR assessment and, if a single of these parameters was abnormal, simple cardiac scan with 2D gray scale and color and/or directional power Doppler in 4-chamber (4-CV) and 3 vessel and trachea views (3VTV) was performed.

RESULTS

The sensitivity and specificity of NT ≥ 95th + DV R/A a-wave + TCR in detecting CHD were 77% and 97%, respectively, and of simple cardiac scan, 67% and 98%, respectively. Area under the curve of receiver operating characteristic curve of NT ≥ 95th + DV R/A a-wave + TCR was 0.838, and of NT ≥ 95th + DV R/A a-wave + TCR + simple cardiac scan was 0.915.

CONCLUSIONS

In chromosomally normal fetuses without non-cardiac anomalies, addition of simple cardiac scan to the combined first trimester screening parameters improves detection of major CHD during first trimester.

Smart-planes fetal heart (S-planes FH) software to quantitative evaluate the fetal great arteries

OBJECTIVES

To explore the feasibility of applying smart-planes fetal heart (S-Planes FH) to 3D volumes to generate and display the outflow tract views (OFTVs) and evaluate its agreement and reliability in determining fetal vessel dimensions.

METHODS

A total of 147 normal fetuses in the second or third trimester were enrolled. Once conventional 2D sonographic examination was finished, one or more 3D static volumes were then acquired in the 4-chamber view (4CV). The OFTVs automatically generated and displayed via a simple offline operation using S-Planes FH software. Per fetus, a single qualified S-Planes FH image was selected by an expert. The inner diameters of the aorta (AO) and pulmonary artery (PA) were measured in 2D and S-Planes FH images, respectively. The agreement and reliability of the two methods were verified by the Bland-Altman method and the intraclass correlation coefficient (ICC), respectively.

RESULTS

A total of 515 3D static volumes were successfully acquired in 147 fetuses. The OFTVs were generated and displayed using S-Planes FH in 138 (93.9%) cases. S-Planes FH had good agreement in measuring the diameters of great arteries (95% CI of limits, -0.9419 to 1.1464 for AO diameter, -0.8871 to 1.7007 for PA diameter). The intraobserver and interobserver ICCs in this study were greater than 0.81, indicating almost perfect reliability of the two methods with regard to observers.

CONCLUSIONS

S-Planes FH software is a feasible method for generating OFTVs as well as determining vessel dimensions in the second and third trimesters and had good agreement with 2D examination. Therefore, it possesses clinical value in screening for CHD and can be operated by different sonographers.

Echocardiographic and pathomorphological features in fetuses with ductal-dependent congenital heart diseases

OBJECTIVE

To individually analyze echocardiographic features in fetuses with ductal-dependent congenital heart diseases (DDCHD) and to verify the anatomical characteristics corresponding to the echocardiogram scan views.

BACKGROUND

Ductal-dependent congenital heart diseases depends on the ductus arteriosus (DA) remaining open to maintain suitable pulmonary or systemic circulation after birth. An accurate diagnosis using prenatal echocardiography has important clinical significance in evaluating disease prognosis and ensuring timely treatment.

METHODS

Fetuses were followed in the prenatal and postpartum periods via echocardiography. The results of postpartum echocardiography or autopsy specimens were compared with the prenatal echocardiography findings.

RESULTS

One hundred and eight fetuses displayed various types of DDCHD including 66 fetuses with ductal-dependent pulmonary circulation, and 42 fetuses with ductal-dependent systemic circulation. Prenatal echocardiography revealed the typical characteristics of no forward flow signal from right ventricular outflow tract to the pulmonary trunk proximally and a reverse flow in the DA in most fetuses for ductal-dependent pulmonary circulation, a reverse flow in the transverse aortic arch for aorta atresia, and a loss of continuity between aortic arch and descending aorta for interruption of the aortic arch (IAA). All 108 fetuses displayed various types of complex CHD, including right ventricular dysplasia with pulmonary atresia (PA), severe Ebstein anomaly, double outlet right ventricle with PA, tetralogy of fallot with PA, single ventricle with PA or aorta atresia, hypoplastic left heart syndrome, and IAA.

CONCLUSIONS

The identification of reverse flow in the aortic arch or DA aids in the subsequent accurate diagnosis of DDCHD associated with complex malformation of the heart.

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.

Genetic anomalies in fetuses with tetralogy of Fallot by using high-definition chromosomal microarray analysis

Background

The etiology of TOF is complex and the genesis of TOF has been associated with environmental factors and genetic disorders, including chromosomal anomalies, aneuploidies, 22q11.2 deletion and single-gene disease. Previous literatures have shown that a chromosome alteration in about 30% patients with TOF and recently published articles reported that 22q11.2 deletion syndrome accounts for 16% cases with TOF diagnosed postnatally. CMA now is considered as gold standard for detecting genetic anomalies in fetuses with congenital malformations. CMA could detect a 6.6–25% incremental yield of CNVs in CHDs. The aim of this study was to assess the genetic anomalies in fetal tetralogy of Fallot (TOF) by using high-definition CMA.

Methods

This retrospective study reviewed all the fetuses diagnosed with TOF between 2013 and 2018. Prenatal ultrasongraphic findings, including cardiac angle, and the findings of CMA using Affymetrix CytoScan HD array were collected.

Results

Ninety-six fetuses with TOF and known genetic results were enrolled. Right aortic arch was the most common associated anomalies (22.9%). One fetus with trisomy 18, one with 46, XX, t (7;10)(q36;q22), one with 47, XYY and five with trisomy 21 were identified. Clinically significant CNVs occurred in 6.8% and uncertain significant CNVs in 3.4% fetal TOF with normal karyotype. A total of four cases with 22q11.2 microdeletion and two fetuses with Yq11.223q11.23 microduplication have been identified. Genetic anomalies, including chromosomal aberrations and pathogenic CNVs, were significantly higher in the TOF with extracardiac anomaly group than in the TOF without extracardiac anomaly group (P = 0.005). Abnormal cardiac angle was noticed in 24.0% fetal TOF. Genetic anomalies were more common in the TOF with abnormal cardiac angle than with normal cardiac angle (P = 0.001). On the other hand, abnormal cardiac angle was noticed in 64.3% fetal TOF with genetic anomalies while abnormal cardiac angle occurred in 17.1% fetal TOF with normal genetic results (P = 0.001).

Conclusions

Genetic testing should be offered, specially using microarray analysis, for the fetal TOF with abnormal cardiac angle or extracardiac defects.

Dynamic fetal cardiac magnetic resonance imaging in four-chamber view using Doppler ultrasound gating in normal fetal heart and in congenital heart disease: comparison with fetal echocardiography

OBJECTIVES

To investigate the diagnostic performance of dynamic fetal cardiac magnetic resonance imaging (MRI), using a MR-compatible Doppler ultrasound (DUS) device for fetal cardiac gating, in differentiating fetuses with congenital heart disease from those with a normal heart, and to compare the technique with fetal echocardiography.

METHODS

This was a prospective study of eight fetuses with a normal heart and four with congenital heart disease (CHD), at a median of 34 (range, 28-36) weeks' gestation. Dynamic fetal cardiac MRI was performed using a DUS device for direct cardiac gating. The four-chamber view was evaluated according to qualitative findings. Measurements of the length of the left and right ventricles, diameter of the tricuspid and mitral valves, myocardial wall thickness, transverse cardiac diameter and left ventricular planimetry were performed. Fetal echocardiography and postnatal diagnoses were considered the reference standards.

RESULTS

Direct cardiac gating allowed continuous triggering of the fetal heart, showing high temporal and spatial resolution. Both fetal cardiac MRI and echocardiography in the four-chamber view detected pathological findings in three of the 12 fetuses. Qualitative evaluation revealed overall consistency between echocardiography and MRI. On both echocardiography and MRI, quantitative measurements revealed significant differences between fetuses with a normal heart and those with CHD with respect to the length of the right (P < 0.01 for both) and left (P < 0.01 for both) ventricles and transverse cardiac diameter (P < 0.05 and P < 0.01, respectively). Tricuspid valve diameter on cardiac MRI was found to be significantly different in healthy fetuses from in those with CHD (P < 0.05).

CONCLUSIONS

For the first time, this study has shown that dynamic fetal cardiac MRI in the four-chamber view, using external cardiac gating, allows evaluation of cardiac anatomy and diagnosis of congenital heart disease in agreement with fetal echocardiography. Dynamic fetal cardiac MRI may be useful as a second-line investigation if conditions for fetal echocardiography are unfavorable. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Is echocardiography necessary for all single umbilical artery fetuses? A retrospective study in a selected Chinese population

AIM

Previous evidence on the relationship between single umbilical artery (SUA) and congenital heart disease (CHD) is controversial. We thus conducted a retrospective study to explore the potential risk factors associated with CHD in SUA fetuses, and verify if all these SUA fetuses should be referred for detail fetal echocardiography.

METHODS

We reviewed medical records of SUA fetuses referred to Xinhua Hospital for fetal echocardiography between September 2009 and February 2014. All the pregnancies were divided into two groups of CHD and non-CHD according to the results of fetal echocardiography. The maternal and fetal characteristics were compared via χ² test and Fishers' test. Furthermore, Poisson regression was used to analyze the risk factors associated with CHD in SUA pregnancies.

RESULTS

Nineteen CHD cases (12.5%) were detected among 152 SUA fetuses, all with abnormal cardiac views during obstetric screening ultrasound (P < 0.001). χ² test showed that abnormal cardiac screening findings, extracardiac abnormality and infection or threatened abortion during first trimester were significantly associated with prenatal detection of CHD (P < 0.001). Multivariable Poisson regression after adjustment found that SUA fetuses with extracardiac abnormality had 4.74 (95% confidence interval: 1.89, 11.90) times higher risk of CHD.

CONCLUSION

Incidence of CHD was higher in SUA cases, and CHD fetuses could be screened efficiently by abnormal cardiac screening during obstetric screening ultrasound. SUA fetuses with extracardiac abnormality and maternal risk factors have higher risk of CHD, and should be strongly recommended for fetal echocardiography. In contrast, SUA fetuses without above situations might only need routine obstetric follow-up.

Z-score reference ranges for pulsed-wave Doppler indices of the cardiac outflow tracts in normal fetuses

To determine Z-score equations and reference ranges for Doppler flow velocity indices of cardiac outflow tracts in normal fetuses. A prospective cross-sectional echocardiographic study was performed in 506 normal singleton fetuses from 18 to 40 weeks. Twelve pulsed-wave Doppler (PWD) measurements were derived from fetal echocardiography. The regression analysis of the mean and the standard deviation (SD) for each parameter were performed against estimated fetal weight (EFW) and gestational age (GA), in order to construct Z-score models. The correlation between these variables and fetal heart rate were also investigated. Strong positive correlations were found between the twelve PWD indices and the independent variables. A linear-quadratic regression model was the best description of the mean and SD of most parameters, with the exception of the velocity time interval (VTI) of ascending aorta against EFW, which was best fitted by a fractional polynomial. Z-score equations and reference values for PWD indices of fetal cardiac outflow tracts were proposed against GA and EFW, which may be useful for quantitative assessment of potential hemodynamic alternations, particularly in cases of intrauterine growth retardation and structural cardiac defects.

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.

2D versus 3D real time ultrasound with live xPlane imaging to visualize aortic and ductal arches: comparison between methods

Background

The diagnosis of congenital heart defects is challenging, especially for what concerns conotruncal anomalies. Indeed, although the screening techniques of fetal cardiac anomalies have greatly improved, the detection rate of conotruncal anomalies still remains low due to the fact that they are associated with a normal four-chamber view. Therefore, the study aimed to compare real-time three-dimensional echocardiography with live xPlane imaging with two-dimensional (2D) traditional imaging in visualizing ductal and aortic arches during routine echocardiography of the second trimester of gestation.

Methods

This was an observational prospective study including 114 women with uncomplicated, singleton pregnancies. All sonographic studies were performed by two different operators, of them 60 by a first level operator, while 54 by a second level operator. A subanalysis was run in order to evaluate the feasibility and the time needed for the two procedures according to fetal spine position and operator’s experience.

Results

The measurements with 2D ultrasound were performed in all 114 echocardiographies, while live xPlane imaging was feasible in the 78% of the cases, and this was mainly due to fetal position. The time lapse needed to visualize aortic and ductal arches was significantly lower when using 2D ultrasound compared to live xPlane imaging (29.56 ± 28.5 s vs. 42.5 ± 38.1 s, P = 0.006 for aortic arch; 22.14 ± 17.8 s vs. 37.1 ± 33.8 s, P = 0.001 for ductal arch), also when performing a subanalysis according to operators’ experience (P < 0.05 for all comparisons). Feasibility of live xPlane proved to be correlated with the position of the fetal spine and the operator’s experience.

Discussion

To find a reproducible and standardized method to detect fetal heart defects may bring a great benefit for both patients and operators. In this scenario live xPlane imaging is a novel method to visualize ductal and aortic arches. We found that the position of the fetal spine may affect the feasibility of the method since, when the fetal back is anterior or transverse, the visualization of the correct view of three-vessels and trachea in order to set the reference line properly becomes more challenging. In addition, the fetal spine position influences the duration of the ultrasound examination. Regarding operator’s skills and experience, in our study a first level operator was able to perform the complete 2D and xPlane examination in a lower number of cases compared to second level operators. In addition, the time required for the complete examination was higher for first level operators. This means that this technique is based on an adequate operators’ expertise.

Impact of prenatal diagnosis on the management and early outcome of critical duct-dependent cardiac lesions

OBJECTIVE

The objective of this study was to compare the preoperative management and outcome of neonates with duct-dependent critical CHD with fetal versus postnatal diagnosis.

METHODS

Patients referred with CHD to our centre from January 1, 2009 to December 31, 2010 were enrolled prospectively. Live births with a critical form of CHD, a gestational age ⩾36 weeks and a weight ⩾2 kg at birth, and the intention-to-treat were included in this sub-study. Excluded were neonates with lethal non-cardiac and/or genetic anomalies.

RESULTS

In total, 129, 63 fetal and 66 postnatal, cases met the study inclusion criteria. All had received appropriate antenatal care, including a routine fetal anatomy scan. Both cohorts were comparable in weight, gestational age, and APGAR scores at birth. Unlike the postnatal cases, there were no deaths (0/63 versus 5/66; p=0.06) and no cardiac arrests (0/63 versus 9/63; p=0.003) before surgery or catheter intervention in those cases with a prenatal diagnosis of critical CHD. Moreover, newborns with fetal diagnoses were admitted earlier (median 0 (range 0-3) versus 2 (0-25) days; p<0.001) and were less likely to require preoperative ventilation (19/63 versus 31/61, p=0.03) and vasoactive medication (4/63 versus 15/61, p=0.006) than the postnatal cases.

CONCLUSIONS

Prenatal diagnosis of critical CHD in this study was associated with significantly shorter time intervals from birth to neonatal admission and the absence of life-threatening or fatal preoperative cardiac events. Increased efforts should be made to improve rates of prenatal diagnosis.

Biventricular impact of mild to moderate fetal pulmonary valve stenosis

OBJECTIVES

To define the pattern of fetal echocardiographic changes associated with isolated pulmonary valve stenosis (PS) and to correlate the echocardiographic findings with neonatal outcome and the need for postnatal pulmonary valvuloplasty within the first 12 months postpartum.

METHODS

This was a prospective cohort study between January 2009 and October 2015 of 16 fetuses with isolated PS and 48 controls matched by gestational age at ultrasound examination (± 2 weeks) evaluated at the Fetal Cardiology Unit at BCNatal (Barcelona). Standard fetal ultrasound and comprehensive echocardiography, which included cardiovascular morphometric parameters, and systolic and diastolic functional and timing measurements, were performed in all cases. Baseline characteristics and perinatal outcome were retrieved from clinical records. Cases were followed up until 12 months of age, and admission to intensive care unit, days of hospitalization, need for prostaglandins and requirement for postnatal surgery were reviewed. Fetal PS cases were analyzed according to the need for postnatal pulmonary valvuloplasty.

RESULTS

The study groups were similar in terms of baseline, fetal ultrasound and perinatal characteristics. Median gestational age at diagnosis of PS was 33.4 (range, 20.0-36.5) weeks. Most cases corresponded to mild or moderate PS; only three fetuses had reversed flow in the ductus arteriosus before delivery. Six (37.5%) newborns, including all three with reversed flow in the ductus arteriosus prenatally, required postnatal pulmonary valvuloplasty. Fetuses with PS presented with larger and more globular hearts, with increased myocardial wall thickness in the third trimester. Despite preserved right ventricular (RV) ejection fraction and systolic longitudinal motion, PS cases showed increased right cardiac output and signs of diastolic dysfunction, with higher ductus venosus pulsatility index (0.72 ± 0.32 vs 0.53 ± 0.16, P = 0.004) and tricuspid E/E' ratio (7.52 ± 3.07 vs 5.76 ± 1.79, P = 0.022). In addition, fetuses with PS displayed a compensatory increase in left ventricular (LV) radial and longitudinal motion, as shown by a higher ejection fraction (79.3 ± 8.23% vs 67.6 ± 11.3%, P = 0.003) and mitral annular-plane systolic excursion (5.94 ± 1.38 vs 5.0 ± 1.22 mm, P = 0.035). Finally, fetuses requiring postnatal pulmonary valvuloplasty showed a different pattern of echocardiographic findings from those not requiring valvuloplasty, with a significantly smaller RV and pulmonary valve diameter, reduced tricuspid annular-plane systolic excursion (5.08 ± 1.59 vs 8.07 ± 1.93 mm, P = 0.028), increased LV cardiac output (340 ± 16 vs 176 ± 44 mL/min/kg, P = 0.003) and more pronounced signs of LV diastolic dysfunction (mitral E' velocity, 5.78 ± 0.90 vs 8.16 ± 1.58 cm/s, P = 0.008).

CONCLUSIONS

Fetuses with PS present with more hypertrophic, larger and more globular hearts in the third trimester of pregnancy, associated with a higher right cardiac output and impaired biventricular relaxation. In addition, signs of increased LV contraction were observed. Our data suggest that RV and LV functional parameters could be useful for predicting the need for postnatal pulmonary valvuloplasty. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Electronic spatiotemporal image correlation improves four-dimensional fetal echocardiography

OBJECTIVES

To compare the efficiency of electronic spatiotemporal image correlation (eSTIC) with that of conventional STIC to acquire four-dimensional (4D) fetal cardiac volumes of diagnostic quality.

METHODS

This was a randomized controlled trial of 100 patients in mid-gestation with normal sonograms. In half of the cases, STIC volumes of the fetal heart were obtained with a conventional mechanical 4D probe and in the remaining cases eSTIC volumes were obtained with an electronic 4D probe. Examinations were kept within the timeframe allotted for a standard examination of fetal anatomy, and a maximum of two attempts were made at obtaining a 4D cardiac volume. Datasets were stored on a computer and subsequently analyzed and categorized as being of optimal, satisfactory or inadequate quality, depending on whether or not it was possible to perform an extended basic cardiac examination, including obtaining a three vessels and trachea view, as well as a clear reconstruction of both the aortic and ductal arches in the sagittal plane.

RESULTS

The eSTIC volume datasets were more frequently of optimal or satisfactory diagnostic quality compared with conventional STIC (94% vs 76%, P < 0.0001). Failure to obtain an eSTIC volume of adequate quality was in all cases the consequence of an unfavorable position of the fetus.

CONCLUSIONS

Compared with a standard mechanical probe, the electronic 4D probe facilitates acquisition of sonographic cardiac volumes in mid-trimester fetuses. In our hands, eSTIC volumes of optimal or satisfactory diagnostic quality, allowing a detailed offline evaluation of the fetal heart, were obtained in more than 90% of cases within the time frame of a standard examination of fetal anatomy. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Isolated Single Umbilical Artery and Fetal Echocardiography: A 25-Year Experience at a Tertiary Care City Hospital

OBJECTIVES

To review our 25-year experience with a single umbilical artery and fetal echocardiography to estimate the need for this test in cases of an isolated single umbilical artery.

METHODS

We conducted a retrospective review of 436 patients with a diagnosis of a single umbilical artery at our institution between 1990 and 2015. Two hundred eighty-eight women had both an anatomic survey and a fetal echocardiogram. Pregnancies with concurrent extracardiac anomalies or aneuploidy were excluded. The study population was divided into 3 groups based on cardiac views on the anatomic survey: normal, incomplete, and suspicious. Echocardiographic results were compared among the 3 groups. The primary outcome measure was the incidence of cardiac anomalies in the normal group at fetal echocardiography. The data were analyzed by the χ² test or Fisher exact test.

RESULTS

The mean maternal age ± SD of the group was 29.2 ± 6.2 years; 44.1% were primiparas. The mean gestational age at diagnosis was 22.6 ± 5.2 weeks, and the mean gestational age at fetal echocardiography was 25.1 ± 3.6 weeks. In the normal group, 99.1% (230 of 232) of women had a normal fetal echocardiogram; the 2 abnormal cases were ventricular septal defects. Normal echocardiograms were obtained in 81.8% (36 of 44) and 25.0% (3 of 12) of the "incomplete" and "suspicious" groups, respectively.

CONCLUSIONS

Fetuses with a single umbilical artery, in the absence of structural abnormalities, and with normal cardiac views at the time of the anatomic survey do not warrant an echocardiogram.