Factors affecting the feasibility of routine first-trimester fetal echocardiography

Feasibility of fetal cardiac biometry measurement at 11-14 weeks scan - a cross-sectional study

OBJECTIVE

To study the feasibility of fetal cardiac biometry measurement between 11 and 14 weeks in low-risk singleton pregnancies.

METHODS

A cross-sectional study was conducted at a single tertiary care center between June 2022 and March 2024 in 129 singleton low-risk mothers in the South Indian population. All subjects included in the study underwent early fetal echocardiography at 11-14 weeks of gestation. The parameters interrogated were the heart length, heart width, heart circumference and area, chest circumference, ventricular chamber length and width, the transverse diameter of aortic and pulmonary annulus, and the transverse diameter of aortic isthmus.

RESULTS

In our study, the success rate of measuring the fetal heart biometry was 33% at 11 weeks, 72% at 12 weeks, and 77% at 13 weeks, respectively. Measurements of outflow tracts and aortic isthmus were difficult. The exclusion of aortic isthmus diameter from the biometric parameters increased the success rate to 50% at 11; weeks, and 80% at 12 and 13 weeks, respectively. Maternal body mass index, any abdominal scar from previous surgeries, and position of placenta had no statistically significant correlation with feasibility of cardiac biometry.

CONCLUSIONS

Our study showed early fetal cardiac biometry is feasible. These measurements can be a helpful tool in the generation of nomograms for the population which can aid early identification of congenital cardiac defects, their follow-up and prognostication.

Simplified First-Trimester Fetal Cardiac Screening Protocol for Low-Risk Pregnancies: Enhancing Efficiency and Accuracy

Introduction

Congenital heart defects (CHDs) are among the most prevalent congenital anomalies and are frequently detected in pregnancies classified as low-risk, rather than in high-risk groups. Advancements in ultrasound technology have heightened the emphasis on first-trimester fetal cardiac screening. However, due to the small size of the fetal heart at this stage, significant challenges persist, underscoring the need for simplified and reproducible protocols that can be effectively applied on a population-wide scale.

Methods

This paper describes a screening approach centred on the four-chamber view (4CV) and three-vessel tracheal view (3VTV) with colour Doppler imaging. This includes optimisation of ultrasound machine settings and the use of transabdominal and transvaginal approaches to enhance visualisation.

Results

Evidence demonstrates a CHD detection rate of 76% in low-risk populations, with a 95% success rate in obtaining the necessary views.

Discussion and Conclusion

Operator expertise and familiarity with cardiac anomalies are critical for accurate detection. The early identification of CHDs enables informed decision-making regarding pregnancy management. A simplified protocol for first-trimester cardiac screening offers a promising tool for the early identification of CHDs, enabling timely referral and intervention. To optimise detection rates and clinical outcomes, continuous professional education and systematic auditing processes are indispensable for practitioners performing early fetal cardiac screening.

Ultrasound Screening in the First and Second Trimester of Pregnancy for the Detection of Fetal Cardiac Anomalies in a Low-Risk Population

Background/Objectives: Congenital heart disease (CHD) is the most common birth defect, an important cause of morbidity and mortality, with a reported prevalence of 5-12 per 1000 live births. The aim of our study was to identify the role of fetal morphological ultrasound examination in the first and second trimester of pregnancy in the detection of fetal congenital cardiac anomalies in a low-risk population. Methods: We performed a retrospective study in a tertiary fetal medicine center in Emergency Hospital Craiova, Romania. The longitudinal analysis combined first- and second-trimester screening using improved ultrasound protocols. Our study evaluated 8944 pregnant women with singleton pregnancies in a 6-year period between January 2018 and December 2023. All ultrasound examinations were performed using a standard extended protocol according to the main guidelines' recommendations for the detection of fetal anomalies. Results: In the first trimester of pregnancy, 37 cases with cardiac anomalies were diagnosed. Thirteen of these cases were associated with genetic anomalies (Down syndrome-eight cases, Edwards syndrome-four cases, Turner syndrome-one case). Some of these pregnancies were associated with at least one of the minor ultrasound markers (inverted ductus venosus, abnormal flow in the tricuspid valve, presence of choroid plexus cysts, absent/hypoplastic nasal bone). In the second trimester of pregnancy, 17 cases of cardiac anomalies were diagnosed. From these cases, one was associated with genetic anomalies (DiGeorge Syndrome), and one case developed hydrops and delivered prematurely in the early third trimester. Conclusions: Ultrasound screening for the detection of congenital heart disease is feasible early in pregnancy, but some anomalies would be obvious later in pregnancy. An early diagnosis using an extended ultrasound protocol, genetic testing, and a multidisciplinary evaluation would improve the prognosis and the overall survival rate by delivering in a tertiary center that allows for rapid cardiac surgery in dedicated cases.

Clinical implementation of first trimester screening for congenital heart defects

OBJECTIVE

To examine the feasibility and performance of implementing a standardized fetal cardiac scan at the time of a routine first-trimester ultrasound scan.

METHOD

A retrospective, single-center study in an unselected population between March 2021 and July 2022. A standardized cardiac scan protocol consisting of a four-chamber and 3-vessel trachea view with color Doppler was implemented as part of the routine first-trimester scan. Sonographers were asked to categorize the fetal heart anatomy. Data were stratified into two groups based on the possibility of evaluating the fetal heart. The influence of maternal and fetal characteristics and the detection of major congenital heart disease were investigated.

RESULTS

A total of 5083 fetuses were included. The fetal heart evaluation was completed in 84.9%. The proportion of successful scans increased throughout the study period from 76% in the first month to 92% in the last month. High maternal body mass index and early gestational age at scan significantly decreased the feasibility. The first-trimester detection of major congenital heart defects was 7/16, of which four cases were identified by the cardiac scan protocol with no false-positive cases.

CONCLUSION

First-trimester evaluation of the fetal heart by a standardized scan protocol is feasible to implement in daily practice. It can contribute to the earlier detection of congenital heart defects at a very low false positive rate.

Evaluation fetal heart in the first and second trimester: Results and limitations

Background

Cardiac heart defects affect nearly 6-12 per 1000 live births in the general population and are more frequent than common trisomies.

Aim

To assess the efficacy and technical limitations of first-trimester fetal heart evaluation in the 11-14^th-weeks' scan and comparison with the second-trimester anatomical exam by ultrasound.

Material and Method

Between April 2015 and July 2020, medical records and ultrasound data of 3295 pregnancies who underwent first-trimester fetal anatomy exams by ultrasound were reviewed retrospectively. All ultrasound exams were performed by the same two operators (TUKD, OP) with transabdominal transducers. Fetal situs, four-chamber view, outflow tracts, and three-vessel trachea view are the cornerstones of first-trimester fetal heart examination. Conventional grayscale mode and high-definition power Doppler mode were utilized. The same operators re-examined all cases between the 18 and 23 weeks of gestation by ISUOG guidelines.

Results

We performed a combined transvaginal and transabdominal approach for only 101 cases (3.06%). The mean maternal age was 31.28 ± 4.43, the median gestational age at the first-trimester ultrasound exam was 12.4 weeks, and the median CRL was 61.87 mm (range was 45.1-84 mm). Even combined approach situs, cardiac axis, and four-chamber view could not be visualized optimally in 28 cases (0.7%). Outflow tracts were visualized separately in 80% (2636 in 3295) cases. Three vessel-trachea views were obtained in 85.4% (2814 in 3295) cases by high-definition Doppler mode. There were 47 fetuses with cardiac defects in 3295 pregnancies with the known pregnancy outcome. Ten cases had abnormal karyotype results. Thirty-two fetuses with cardiac anomalies (9.7 in 1000 pregnancies) were detected in the first-trimester examination, and the remaining 15 (4.55 in 1000 pregnancies) cases were diagnosed in the second-trimester examination. The prevalence of congenital cardiac anomalies was 14.25 in 1000 pregnancies. Fifteen cases were missed in the first-trimester exam. Also, ten fetuses which had abnormal cardiac findings in the first-trimester exam were not confirmed in the second-trimester exam. Sensitivity, specificity, positive, and negative predictive values were calculated as 65.3%, 99.7%, 66.8%, and 99.67%, respectively.

Conclusion

Late first-trimester examination of the fetus is feasible and allows earlier detection of many structural abnormalities of the fetus, including congenital heart defects. Suspicious and isolated cardiac abnormal findings should be re-examined and confirmed in the second-trimester exam. Previous abdominal surgery, high BMI, and subtle cardiac defects can cause missed cardiac abnormalities.

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.

HDlive Flow Silhouette with spatiotemporal image correlation for assessment of fetal cardiac structures at 12 to 14 + 6 weeks of gestation

OBJECTIVES

To assess fetal cardiac structures using HDlive Flow Silhouette with spatiotemporal image correlation (STIC) at 12 to 14 + 6 weeks of gestation, and verify the feasibility of obtaining five cardiac views in the late first and early second trimesters of pregnancy. The fetal cardiac shape and the aspect of the descending aorta were also evaluated.

METHODS

Eighty normal fetuses at 12 to 14 + 6 weeks of gestation were studied using trans-abdominal HDlive Flow Silhouette with STIC to assess the feasibility of five fetal cardiac views (frontal, spatial three-vessel, panoramic, posterior, and right lateral views). Target structures in each cardiac view were evaluated. 'Good' was assigned when all structures were noted, 'Fair' when only one structure was missed, and 'Poor' when two and more structures could not be detected. Frequencies of an elongated heart and those of a tortuous descending aorta were counted.

RESULTS

Forty-nine fetuses were effectively included in the analysis. Success rates of 'Good' and 'Fair' were significantly higher with spatial three-vessel (p<0.01) and panoramic views (p<0.05). Frequencies of "Elongated heart", "Elongated left ventricle", and "Spherical heart" were 12.2, 6.2, and 81.6%, respectively. Frequencies of "Tortuous descending aorta" and "Straight descending aorta" were 12.2 and 87.8%, respectively.

CONCLUSIONS

The feasibility of obtaining fetal five cardiac views using HDlive Flow Silhouette with STIC is good, and this technique provides useful information for evaluating fetal cardiac structures in the late first and early second trimesters of pregnancy.

First trimester fetal echocardiography limitations and its expected clinical values

BACKGROUND

Fetal cardiac activity could be observed between 6th and 7th gestational weeks, early performance of fetal echocardiography could be implemented to screen for fetal heart disease. The effectiveness of early first trimester fetal echocardiography has not been adequately investigated, especially with modern sonographic technological advances. The purpose of the study is to evaluate the capability to visualize fetal cardiac structures within the first trimester as early as 10th gestational weeks and to elucidate the value of using color Doppler in visualization of cardiac structures within early gestation. A prospective clinical trial conducted on 150 study subjects, 44 of them were twin gestations. Cases were fully assessed by fetal echocardiographic examination from 10th gestational week to 13 gestational weeks in a sequential manner weekly. The research study was conducted at cardiology department fetal unit in one of the tertiary hospitals.

RESULTS

Four chamber view was mostly visualized from 12 gestational weeks, whereas cardiac axis was fully visualized in all cases from 12 gestational weeks; on the other hand, IVC assessment by 2D was satisfactorily visualized in 78.26% of cases and by color Doppler in 82.61% of cases at 13 gestational weeks, pulmonary veins were visualized in 21.74% of cases by 2D and 43.5% of cases by color Doppler at 13 gestational weeks, and interestingly, ventricular inflows were satisfactorily visualized in almost all cases from 10th gestational weeks.

CONCLUSIONS

First trimester fetal echo is an outstanding enhancement in management pathways of cases susceptible to have fetal cardiac abnormalities permitting early detection of structural cardiac anomalies triggering a cascade of scanning for extra cardiac anomalies to aid in evaluation and assessment of the best management course for those affected cases.

Sonographic Evaluation of Fetal Cardiac Anatomy in the Late First Trimester

Objective:

Congenital heart defects (CHDs) are the most common cause of infant death in the United States. Severe, complex cardiac anomalies make up approximately half of the cases and carry significant morbidity and mortality. The purpose of this literature review was to define a CHD screening protocol to be used in the first trimester.

Methods:

Literature was pulled that discussed the impact of color Doppler and spatiotemportal image correlation on image quality, explored the benefits and limitations of early screening, and analyzed the risk of bioeffects to the developing fetus.

Results:

A simplified cardiac screening protocol has been shown to be a feasible addition to the first trimester nuchal translucency scan.

Conclusion:

Color Doppler and three-dimensional sonography can be utilized during the first trimester to evaluate the fetal heart for major anomalies between 11 weeks and 13 weeks 6 days. Recommendations for future research and guidance from accrediting bodies are provided.

Early fetal echocardiography

OBJECTIVES

To explore the technical aspects and clinical utility of early fetal echocardiography and screening of the fetal heart in early pregnancy. Also, to document differences in cardiac structure and function which can be demonstrated in the late first/early second trimesters.

METHODS

In addition to summarizing our own experiences of late first/early second trimester fetal echocardiography, we reviewed the literature to explore clinical indications for, technical aspects, safety, accuracy, strengths and weaknesses of early fetal echocardiography.

RESULTS

In the current era, an increasing number of fetuses are identified as being at risk of congenital heart disease from as early as the late first trimester. In experienced hands, early fetal echocardiography can pick up a high proportion of congenital heart disease with good reliability for the majority of lesions. Early fetal echocardiography is relatively poor at assessing pulmonary veins, the atrioventricular valves and lesions that typically occur later or progress during the course of pregnancy. There is increasing interest in widespread implementation of an early obstetric anomaly screen which includes an assessment of the fetal heart for all pregnancies. There are a variety of hemodynamic differences in the late first/early second trimester compared with later in pregnancy.

CONCLUSION

Early fetal echocardiography is has become an established tool for detection of congenital heart disease. It affords opportunities to learn about the true spectrum and progression of congenital heart disease in-utero. Operators should be mindful of safety issues, technical aspects and hemodynamic findings which differ when performing echocardiograms at this stage of pregnancy.

The first trimester combined test for aneuploidies - a single center experience

PURPOSE

We present the results of the systematic application of the first trimester combined test for aneuploidies, in a Romanian center.

METHODS

Since October 2009, in Filantropia Hospital in Bucharest, we have systematically been using the FMF (Fetal Medicine Foundation) combined first trimester test to screen for common aneuploidies at 11 to 13 + 6 weeks of gestation. We assessed the crown to rump length (CRL), nuchal translucency, fetal heart rate as well as PAPP-A, and free β-hCG in maternal serum. We evaluated additional first trimester ultrasound markers in most of the cases. The individual risk for aneuploidies was calculated using the FMF algorithm.

RESULTS

Pregnancy outcome is known for 6030 euploid fetuses and 42 aneuploid fetuses from our screening population. The detection rate for trisomy 21 of the combined test was 87.5% for a screen positive rate of 1.96%. All of the trisomy 18 and trisomy 13 cases were detected prenatally. Some of the trisomy 18 cases proved not to be symptomatic in the first trimester.

CONCLUSIONS

Our results are similar to those of the main studies on the FMF method of first trimester screening for aneuploidies. Our numbers are small because of limited availability of the very specialized resources involved.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

How to Acquire Cardiac Volumes for Sonographic Examination of the Fetal Heart: Part 1

Four-dimensional sonography with spatiotemporal image correlation (STIC) technology allows acquisition of a fetal cardiac volume data set and displays a cine loop of a complete single cardiac cycle in motion. Part 1 of this 2-part article reviews STIC technology and its features, the importance of operator training/experience, and acquisition of high-quality STIC volumes, as well as factors that affect STIC volume acquisition rates. We also propose a detailed and practical stepwise approach to performing 4-dimensional sonography with STIC and begin herein by providing general recommendations. Part 2 will discuss specifics of the approach, along with how to determine whether such volumes are appropriate for analysis.