Diagnostic accuracy of prenatal ultrasound in coarctation of aorta: systematic review and individual participant data meta-analysis

Reproducibility Challenges in Fetal Cardiac Function Analysis with 2D Speckle-Tracking Echocardiography: Insights from FetalHQ

Background/Objectives: Functional assessment of the fetal heart remains a significant challenge in contemporary perinatology due to the absence of a universally accepted gold standard for such evaluations. The aim of this study was to evaluate the reproducibility of parameters derived from two-dimensional speckle-tracking echocardiography (2D STE) using the FetalHQ software. Methods: We enrolled 87 pregnant women between 19 and 23 weeks of gestation who were undergoing mid-trimester screening at the Provincial Hospital Complex in Kielce. Two independent operators acquired 5 s cine-loops of four-chamber views (4CVs) according to a standardized protocol. Reproducibility was assessed by examining intra- and interobserver variability using the intraclass correlation coefficient (ICC) for several cardiac parameters, including the global sphericity index (GSI), global longitudinal strain (GLS), stroke volume (SV), and fractional area change (FAC). Results: Reproducibility varied substantially across the assessed parameters. The highest intraobserver reproducibility was observed for the 4CV GSI (ICC > 0.9). Moderate intraobserver reproducibility (ICCs ranging from 0.5 to 0.75) was noted for left ventricular (LV) parameters, such as end-diastolic area, end-systolic area, end-diastolic volume, and end-systolic volume. Interobserver variability demonstrated higher ICC values, with excellent reproducibility (ICC > 0.9) for the 4CV GSI and LV volume measurements. Good reproducibility (ICCs between 0.75 and 0.9) was observed for specific left ventricular segmental strain indices, whereas other parameters showed moderate to poor reproducibility (ICC < 0.5). Conclusions: Two-dimensional speckle-tracking echocardiography (2D STE) using FetalHQ exhibits variable reproducibility, which is influenced by the choice of parameters, operator experience, and technical factors. This method holds potential for fetal cardiac assessment; however, additional research is required to improve its predictive accuracy and streamline the evaluation process for routine clinical application.

Urgent and emergent pediatric cardiovascular imaging

The need for urgent or emergent cardiovascular imaging in children is rare when compared to adults. Patients may present from the neonatal period up to adolescence, and may require imaging for both traumatic and non-traumatic causes. In children, coronary pathology is rarely the cause of an emergency unlike in adults where it is the main cause. Radiology, including chest radiography and computed tomography in conjunction with echocardiography, often plays the most important role in the acute management of these patients. Magnetic resonance imaging can occasionally be useful and may be suitable in more subacute cases. Radiologists' knowledge of how to manage and interpret these acute conditions including knowing which imaging technique to use is fundamental to appropriate care. In this review, we will concentrate on the most common cardiovascular emergencies in the thoracic region, including thoracic traumatic and non-traumatic emergencies and pulmonary vascular emergencies, as well as acute clinical disorders as a consequence of primary and postoperative congenital heart disease. This review will cover situations where cardiovascular imaging may be acutely needed, and not strictly emergencies only. Imaging recommendations will be discussed according to the different clinical presentations and underlying pathology.

Routine 36-week scan: diagnosis of fetal abnormalities

OBJECTIVES

To investigate further the incidence and types of fetal abnormality identified at a routine 36-week ultrasound examination, which had not been diagnosed in previous scans at 20 weeks and 12 weeks' gestation, and to report the fetal abnormalities that are diagnosed only postnatally.

METHODS

This was a prospective study of 104 151 women with a singleton pregnancy attending for a routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation. In each case, a detailed examination was carried out for the diagnosis of fetal abnormality. All women had undergone a previous ultrasound examination at 19 + 0 to 23 + 6 weeks and 95 801 (92.0%) women also had a scan at 11 + 0 to 14 + 1 weeks. We excluded pregnancies with known aneuploidy. Fetal abnormalities were classified according to the affected major organ system, and the type and incidence of new abnormalities were determined.

RESULTS

There were four main findings of this study. First, in the study population, abnormality was identified in 2552 (2.5%) fetuses/neonates. Second, at the 36-week scan, abnormality was detected in 2144 (2.1%) fetuses and the most common abnormalities first detected at the 36-week scan were ventricular septal defect, unilateral or bilateral hydronephrosis, unilateral empty renal fossa (with or without pelvic kidney), unilateral or bilateral duplex kidney and mild ventriculomegaly. Third, 1341 (62.5%) of the fetuses with abnormality detected at the 36-week scan had been diagnosed previously during the first or second trimester and therefore, the incidence of abnormality detected for the first time in the third trimester was 0.77% (803/104 151). The most common abnormalities that were diagnosed exclusively for the first time during the third-trimester scan were ovarian cyst, achondroplasia, microcephaly, vein of Galen malformation and hematocolpos. Fourth, the incidence of abnormality detected for the first time postnatally was 0.39% (408/104 151). The most common abnormalities detected for the first time postnatally were polydactyly, oligodactyly or syndactyly, hypospadias/epispadias, mild talipes treated with physiotherapy, ventricular septal defect and isolated cleft palate. The most common abnormalities diagnosed exclusively for the first time postnatally were isolated cleft palate, anal atresia, atrial septal defect and esophageal atresia with fistula.

CONCLUSION

A high proportion of fetal abnormalities are detected for the first time during a routine 36-week scan. Such diagnosis and subsequent management, including the selection of timing and place for delivery and postnatal investigation, could potentially improve postnatal outcome. © 2025 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Second trimester echocardiography

Fetal echocardiography involves a comprehensive cardiac assessment aiming to make a complete structural examination of the heart as well as to detect signs of cardiovascular adaptation to different insults. For the former, this assessment entails expert's evaluation of the anatomy of the heart including additional views beyond the five axial views used in cardiac screening examinations and always complemented with colour and pulsed Doppler. Echocardiography may accurately diagnose most congenital heart defects in fetal life, which enables adjusting the perinatal management. For the latter, echocardiography encompasses cardiac morphometric assessment to identify signs of cardiac remodeling indicative of cardiac adaptation in structure, shape, and size in response to underlying diseases, and cardiac functional assessment to detect signs of systolic and/or diastolic dysfunction. The most used parameters to study the systolic function (stroke volume, cardiac output, ejection fraction, fractional shortening, and mitral and tricuspid annular plane systolic excursion), diastolic function (characteristics of flow in the precordial veins and through the atrioventricular valves) and global myocardial function (myocardial performance index) will be discussed in this review.

A New Method Using the Four-Chamber View to Identify Fetuses With Subsequently Confirmed Postnatal Aortic Coarctation

OBJECTIVE

To determine the sensitivity, specificity, and false-positive rate among fetuses suspected prenatally to have coarctation of the aorta (CoA) using size and shape measurements of the fetal heart from the four-chamber view (4CV).

METHODS

This was a retrospective study of 108 fetuses identified by pediatric cardiologists to be at risk for CoA. 4CV s from the last antenatal ultrasound performed by the cardiologists were analyzed. The end-diastolic area was computed using the point-to-point trace method around the epicardial border of the 4CV, and the largest end-diastolic length and width were measured from the epicardium to the epicardium to compute the global sphericity index (GSI) (length/width). Using speckle tracking analysis, the ventricular end-diastolic area, length, basal and mid-chamber widths were measured. The sphericity index of the base and mid-chamber of the ventricles was computed (length/width). In addition, the end-diastolic area ratios were computed as follows: right ventricular area/4CV area and the left ventricular area/4CV area. The z-scores for the above measurements were computed. Using logistic regression analysis, coefficients for predicting the probability of CoA from a test group of 27 fetuses with CoA and 27 without CoA was done. The logistic regression equation derived from the test group was applied to a validation group of 27 fetuses with CoA and 27 fetuses without CoA.

RESULTS

The regression equation from the test group identified the following end-diastolic measurements: 4CV GSI, RV area/heart area, LV base SI, and the RV Base SI. The test group consisted of 14 of 27 fetuses with an isolated CoA (52%) and 13 of 27 (48%) with additional heart abnormalities. For the validation group, 10 of 27 (37%) had an isolated CoA, and 17 (63%) had additional cardiac abnormalities. Using the logistic regression equation derived from the test group (54 fetuses: 27 with CoA and 27 without CoA), the validation group (54 fetuses: 27 with CoA and 27 without CoA) demonstrated the following: sensitivity for detecting CoA of 98.15%, specificity 98.15%, and a false-positive rate of 1.85%. When the logistic regression was applied to the test group of fetuses with isolated CoA, 100% (14/14) were identified with logistic regression analysis. For the validation group, 9 of 10 (90%) of fetuses with isolated CoA were identified using the logistic regression equation.

CONCLUSIONS

Using length, width, and area measurements of the 4CV and ventricles from which ratios are computed detects 98.15% of high-risk fetuses who will demonstrate CoA following birth, with a specificity of 98.15%, or a false-positive rate of 1.85%.

A novel diagnostic model for fetal coarctation of the aorta with ventricular septal defect

BACKGROUND

Our study aimed to develop a novel diagnostic model for fetal coarctation of the aorta with ventricular septal defect(CoA/VSD).

METHODS AND RESULTS

We respectively included 70 fetuses with suspected CoA/VSD(January 2017-June 2023). After birth, 26 fetuses (26/47, 55.3 %) were confirmed to be true-positive CoA/VSD (TP-CoA/VSD), 21 cases had only VSDs without CoA, namely false-positive CoA/VSD (FP-CoA/VSD), and the remaining 23 fetuses were excluded due to additional major malformations, multiple pregnancies or other reasons. Large VSDs and doubly committed subarterial VSDs were more prevalent in true coarctation fetuses(all p < 0.05). Among morphological parameters of echocardiography, the aortic isthmus (AoI)/VSD ratio had the highest area under the curve (AUC) of 0.81 (95 % CI: 0.68-0.94, p < 0.001) and cutoff value of ≤0.67. Three new diagnostic models were constructed by adding different functional variables, namely left ventricular longitudinal strain(LVLS), LV ejection fraction, and LV fractional area of change to the morphological variable AoI/VSD ratio. The diagnostic model of AoI/VSD ratio and LVLS had the highest AUC of 0.96 (95 % CI: 0.86-1.00; p < 0.001). In addition, risk stratification revealed a high risk of prenatal CoA/VSD when the risk probability was greater than 0.80, which required early medical counseling and intervention.

CONCLUSIONS

In fetuses suspected with having CoA/VSD, myocardial strains of both ventricles were lower in true CoA group. Additionally, a diagnostic model of new morphological parameter AoI/VSD ratio and functional variable LVLS, was highly valuable in diagnosing fetal CoA/VSD.

The Role of Collaboration in Prenatal Congenital Heart Disease Diagnosis: A Comparison of Maternal-Fetal Medicine Specialist and Pediatric Cardiologist Performance

OBJECTIVE

This study compared the accuracy of prenatal congenital heart disease (CHD) diagnosed by maternal-fetal medicine specialists (MFMs) and pediatric cardiologists (PCs), using postnatal cardiac findings as the reference standard.

METHODS

This retrospective analysis at Siriraj Hospital, Bangkok, Thailand, involved 125 pregnancies with fetal CHD diagnosed by MFMs and evaluated by PCs later. Prenatal CHD diagnoses by either MFM or PC were compared with postnatal diagnoses obtained through echocardiography, cardiac surgery/catheterization, or autopsy. Diagnostic accuracy was classified as (A) correct diagnosis, (B) minor differences not impacting clinical management or outcomes, or (C) major differences affecting prognosis or treatment.

RESULTS

Cardiac sonography by MFM achieved diagnostic accuracies of 73.6% (A), 16% (B), and 10.4% (C), while fetal echocardiography by PC resulted in accuracies of 72% (A), 20% (B), and 8% (C). No statistically significant differences were found between MFM and PC in each category (P = .375-.832). The MFMs' accuracy was highest for tetralogy of Fallot (94.4%; 95% CI, 72.7-99.9%) and lowest for right atrial isomerism (71.4%; 95% CI, 29-96.3%) and pulmonary atresia with ventricular septal defect (57.1%; 95% CI, 18.4-90.1%).

CONCLUSIONS

MFMs and PCs demonstrated high and comparable accuracy in prenatal CHD diagnosis. Although PCs tended to outperform MFMs in cases where misdiagnosis could significantly impact neonatal care and outcomes, MFMs can effectively perform primary screening for fetal CHD in all pregnancies. Collaboration with PCs remains essential when fetal CHD is suspected, particularly in complex cases.

Aortic isthmus flow reversal in fetal coarctation of the aorta and the associated factors

INTRODUCTION

The aim of this study was to investigate the presence of aortic isthmus flow reversal and its associated factors in fetuses with positive and false-positive coarctation of the aorta (CoA) compared with normal controls.

MATERIAL AND METHODS

Pregnant women with fetuses suspected of CoA and normal control were enrolled, and these women experienced prenatal ultrasound scan and followed up for 6 months after birth to confirm the presence of CoA. All the ultrasound parameters were analyzed.

RESULTS

A total of 134 pregnant women were enrolled, with 43 CoA-positive fetuses and 91 CoA false-positive fetuses, and 334 matched pregnant women were enrolled in the control group. Aortic isthmus flow reversal occurred in 28 (65.1%) fetuses in the CoA-positive group, significantly (p < 0.05) more than in the false-positive (37 or 40.7%) or control group (64 or 19.2%). Aortic isthmus flow reversal was mostly in the full systole (n = 17 or 60.7%) or late systole and early-middle diastole (n = 10 or 35.7%) in the CoA-positive fetuses (n = 27 or 96.4%), significantly (p < 0.001) different from that in the false-positive or control group. The aortic isthmus flow reversal peak systolic velocity (PSV), flow volume, and ratio of reversed flow/forward flow were significantly (p < 0.05) increased in the CoA-positive and false-positive groups than in the control group. The aortic isthmus flow reversal incidence was significantly (p < 0.05) correlated with the middle cerebral artery (MCA) PSV in the total three groups or in the false-positive group but was significantly (p < 0001) negatively correlated with the MCA resistance index (RI) in the CoA-positive group. The incidence of the aortic isthmus flow reversal was significantly (p < 0.05) positively correlated with the umbilical artery (UA) RI in the false-positive group and with the UA RI in the total three groups. Independently associated factors for aortic isthmus flow reversal were isthmic flow volume/CCO (combined cardiac output) in the CoA-positive group.

CONCLUSIONS

Reversal of flow in the aortic isthmus is much more common in true-positive cases of CoA as compared to controls, and isthmic flow reversal in the full systolic phase only suggests presence of CoA. The aortic isthmic reversed flow volume accounts for over half of the isthmic forward flow volume in the CoA-positive fetuses than in the normal controls.

The Holy Grail of obstetric ultrasound: can artificial intelligence detect hard-to-identify fetal cardiac anomalies?

Linked article: This Editorial comments on articles by Day et al. and Taksøe‐Vester et al.

Prenatal Diagnosis of Congenital Heart Disease: The Crucial Role of Perinatal and Delivery Planning

Although most congenital heart defects (CHDs) are asymptomatic at birth, certain CHD lesions are at significant risk of severe hemodynamic instability and death if emergent cardiac interventions are not performed in a timely fashion. Therefore, accurate identification of at-risk fetuses and appropriate delivery resource planning according to the degree of anticipated hemodynamic instability is crucial. Fetal echocardiography has increased prenatal CHD detection in recent years due to advancements in ultrasound techniques and improved obstetrical cardiac screening protocols, enabling the prediction of newborns' hemodynamic status. This assessment can guide multidisciplinary resource planning for postnatal care, including selection of delivery site, delivery room management, and transport to a cardiac center based on CHD risk severity. This review will discuss fetal cardiovascular physiology and the circulatory changes that occur at the time of and immediately following birth, outline fetal echocardiographic findings used to risk-stratify newborns with CHDs, and outline principles for neonatal resuscitation and initial transitional care in neonates with these complex CHD lesions.