Contribution of the Fetal Cardiac Axis and V-Sign Angle in First-Trimester Screening for Major Cardiac Defects

Prenatal Diagnosis and Clinical Phenotypic Heterogeneity of 22q11.2 Microdeletion Syndrome Based on a Single Center Retrospective Study

OBJECTIVE

To retrospectively investigate the incidence of prenatal diagnosis of 22q11.2 microdeletion syndrome (22q11.2DS) in a single center and summarize its clinical manifestations to expand the phenotypic database.

METHODS

Pregnant women who underwent prenatal diagnosis at The Women and Children's Hospital, School of Medicine, Xiamen University, from January 2018 to February 2024 were retrospectively analyzed. Prenatal diagnosis was performed using routine G-banding karyotype analysis and chromosomal microarray analysis (CMA) or copy number variation sequencing (CNV-seq). Fetuses diagnosed with 22q11.2DS were further analyzed using detailed ultrasound diagnostic records to summarize the clinical manifestations of 22q11.2DS.

RESULTS

A total of 24,319 pregnant women underwent prenatal diagnosis, and 24 cases were diagnosed with 22q11.2DS, with an incidence of 0.99‰ (24/24319), including 16 cases of congenital heart disease, 4 cases of renal pelvis separation, 3 cases of cleft lip and palate, 2 cases of double strephenopodia, 2 cases of nasal bone dysplasia, and 1 case each of unclear thymus, spina bifida with meningomyelocele, abnormal fetal growth retardation, and NT thickening.

CONCLUSION

Congenital heart disease was the most common phenotype in 22q11.2DS, and other malformations also occurred in a certain proportion. In addition, some rare clinical phenotypes, such as spina bifida with myelomeningocele and nasal bone hypoplasia, were also found in this cohort, which should be taken seriously to improve the detection rate of fetal 22q11.2DS.

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.

Detection of non-cardiac fetal abnormalities on ultrasound at 11-14 weeks: systematic review and meta-analysis

OBJECTIVES

To assess the diagnostic accuracy of two-dimensional ultrasound at 11-14 weeks' gestation as a screening test for individual fetal anomalies and to identify factors impacting on screening performance.

METHODS

This was a systematic review and meta-analysis that was developed and registered with PROSPERO (CRD42018111781). MEDLINE, EMBASE, Web of Science Core Collection and the Cochrane Library were searched for studies evaluating the diagnostic accuracy of screening for 16 predefined, non-cardiac, congenital anomalies considered to be of interest to the early anomaly scan. We included prospective and retrospective studies from any healthcare setting conducted in low-risk, mixed-risk and unselected populations. The reference standard was the detection of an anomaly on postnatal or postmortem examination. Data were extracted to populate 2 × 2 tables and a random-effects model was used to determine the diagnostic accuracy of screening for the predefined anomalies (individually and as a composite). Secondary analyses were performed to determine the impact on detection rates of imaging protocol, type of ultrasound modality, publication year and index of sonographer suspicion at the time of scanning. Post-hoc secondary analysis was conducted to assess performance among studies published during or after 2010. Risk of bias assessment and quality assessment were undertaken for included studies using the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

From 5684 citations, 202 papers underwent full-text review, resulting in the inclusion of 52 studies comprising 527 837 fetuses, of which 2399 were affected by one or more of the 16 predefined anomalies. Individual anomalies were not equally amenable to detection on first-trimester ultrasound: a high (> 80%) detection rate was reported for severe conditions, including acrania (98%), gastroschisis (96%), exomphalos (95%) and holoprosencephaly (88%); the detection rate was lower for open spina bifida (69%), lower urinary tract obstruction (66%), lethal skeletal dysplasias (57%) and limb-reduction defects (50%); and the detection rate was below 50% for facial clefts (43%), polydactyly (40%) and congenital diaphragmatic hernia (38%). Conditions with a low (< 30%) detection rate included bilateral renal agenesis (25%), closed spina bifida (21%), isolated cleft lip (14%) and talipes (11%). Specificity was > 99% for all anomalies. Secondary analysis showed that detection improved with advancing publication year, and that the use of imaging protocols had a statistically significant impact on screening performance (P < 0.0001).

CONCLUSIONS

The accurate detection of congenital anomalies using first-trimester ultrasound is feasible, although detection rates and false-positive rates depend on the type of anomaly. The use of a standardized protocol allows for diagnostic performance to be maximized, particularly for the detection of spina bifida, facial clefts and limb-reduction defects. Highlighting the types of anomalies amenable to diagnosis and determining factors enhancing screening performance can support the development of first-trimester anomaly screening programs. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

First-Trimester Ultrasound Screening in Routine Obstetric Practice

Technologic advances and ultrasonographer-physician experience in fetal imaging have led to significant improvements in our ability to distinguish between normal and abnormal fetal structural development in the latter part of the first trimester. As a critical component of pregnancy care, assessment of fetal anatomy at the end of the first trimester with a standardized imaging protocol should be offered to all pregnant patients regardless of aneuploidy screening results because it has been demonstrated to identify approximately half of fetal structural malformations. Early identification of abnormalities allows focused genetic counseling, timely diagnostic testing, and subspecialist consultation. In addition, a normal ultrasound examination result offers some degree of reassurance to most patients. Use of cell-free DNA alone for aneuploidy screening while foregoing an accompanying early anatomic evaluation of the fetus will result in many anomalies that are typically detected in the first trimester not being identified until later in pregnancy, thus potentially diminishing the quality of obstetric care for pregnant individuals and possibly limiting their reproductive options, including pregnancy termination.

Cardiac Axis in Early Gestation and Congenital Heart Disease

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

Reappraising the Value of Fetal First-Trimester Ultrasonography

In the last few years, the introduction of cell-free DNA has rapidly altered prenatal screening regimens and is increasingly offered as the second- or, at times, even the first-tier screening test. Should an early anomaly scan also be part of an up-to-date screening policy? This paper reappraises the value of fetal first-trimester ultrasonography. The primary aims of the first-trimester scan are to establish gestational age based on the measurement of fetal crown-rump length, to detect multiple pregnancy and chorionicity, and to measure fetal nuchal translucency thickness as part of a combined screening test for chromosomal abnormalities. With recent advancements in ultrasound technology, there is compelling evidence that a majority of fetuses with major structural abnormalities and almost half of them without chromosomal abnormalities can be detected in the first trimester. We focused on the first-trimester screening of fetal major defects, especially including fetal congenital heart disease and cleft lip and palate by ultrasound markers and views. Moreover, it is critical to highlight that after a detailed anomaly scan in the first trimester without major structural anomalies and positive genetic tests, the residual chance of favorable outcome in fetuses with isolated increased nuchal translucency is relatively high. The discussion on the role of cell-free DNA in prenatal screening is still ongoing. Even in the event of it becoming a first-line screening test for aneuploidies, the importance of a first-trimester fetal scan, including assessment of markers for other anomalies, remains undisputed.

Should Prenatal Chromosomal Microarray Analysis Be Offered for Pulmonary Atresia? A Single-Center Retrospective Study in China

(1) Objective: To evaluate the application of chromosomal microarray analysis (CMA) in fetuses with pulmonary atresia (PA) and to explore the risk factors for predicting chromosomal imbalances and adverse perinatal outcomes. (2) Methods: This study investigated 428 cases of PA singleton pregnancies that were tested using CMA and quantitative fluorescent polymerase chain reaction (QF-PCR) as first-line genetic testing. The PA cases were divided into two groups: an isolated group and a non-isolated group. (3) Results: CMA revealed clinically relevant copy number variations (CNVs) in 9/139 (6.47%) PA fetuses, i.e., pathogenic copy number variations (pCNVs) in 8/139 (5.76%) fetuses and likely pathogenic CNVs in 1/139 (0.72%) fetuses. Stratified analysis showed that the incidence of clinically significant variants was higher in non-isolated PA fetuses than in isolated PA fetuses (12.50%, 6/48 vs. 3.30%, 3/91, p = 0.036). Regression analysis showed that a combination of other structural abnormalities at diagnosis of PA represented the principal risk factor for chromosomal imbalances (OR = 2.672). A combination of other structural abnormalities and a high maternal age increased the risk of adverse pregnancy outcomes in PA cases, including intrauterine fetal death (IUFD), termination of pregnancy (TOP), and preterm delivery. (4) Conclusions: The value of CMA for locating imbalanced genetic variations in fetuses with PA was highlighted by this study, particularly when combined with additional structural abnormalities.

Utility of fetal cardiac magnetic resonance imaging in assessing the cardiac axis in fetuses with congenital heart disease

BACKGROUND

Fetal dedicated echocardiography is the standard to measure the fetal cardiac axis. However, fetal screening ultrasound (US) or fetal dedicated echocardiography may be technically limited.

OBJECTIVE

The purpose of this study was to explore the accuracy of fetal cardiac magnetic resonance imaging (MRI) to measure the cardiac axis in fetuses with congenital heart disease as an adjunct to fetal dedicated echocardiography and to assess the predictive value of fetal cardiac MRI measurements in distinguishing healthy fetuses from fetuses with congenital heart disease.

MATERIALS AND METHODS

This is a retrospective study of fetuses referred to our hospital for a fetal cardiac MRI from November 2019 to December 2021. Cardiac axes were measured in the 4-chamber view of the fetal heart using fetal cardiac MRI and dedicated echocardiography, or only using fetal cardiac MRI when screening US was technically limited. The fetuses were divided into a congenital heart disease group and a healthy control group. We used Bland-Altman analysis and the intraclass correlation coefficient (ICC) to assess the agreement of cardiac axis measurements in fetuses with congenital heart disease obtained by cardiac MRI and by fetal dedicated echocardiography. Receiver operating characteristic (ROC) curve analysis of the fetal cardiac axes in the congenital heart disease and healthy fetus groups assessed the predictive value of the cardiac axis measurements.

RESULTS

This retrospective study included 431 women (162 carrying fetuses with congenital heart disease, 269 carrying healthy fetuses). Cardiac axes were measured in the 162 fetuses with congenital heart disease using fetal cardiac MRI and dedicated echocardiography. Cardiac axes were measured in the 269 healthy control fetuses using fetal cardiac MRI when fetal screening US was technically limited. The interobserver analysis and intraobserver analysis showed that the cardiac axis measured by fetal cardiac MRI and fetal dedicated echocardiography was repeatable (ICC>0.90). In 162 fetuses with congenital heart disease, Bland-Altman analysis showed a strong agreement between cardiac MRI and fetal dedicated echocardiography measurements for the cardiac axis. The ICC for the cardiac axis values between cardiac MRI and fetal dedicated echocardiography measurements was 0.99. In fetuses with congenital heart disease, 64.2% (104/162) had an abnormal cardiac axis. For the fetal cardiac axis in both the 162 fetuses with congenital heart disease and the 269 healthy fetuses, the area under the ROC curve reached 0.85 (95% confidence interval: 0.80-0.89; P<0.0001).

CONCLUSION

The cardiac axis can be accurately measured using fetal cardiac MRI when fetal dedicated echocardiography/fetal screening US is technically limited. The cardiac axis measurements by fetal cardiac MRI are consistent with known cardiac axis measurements by fetal dedicated echocardiography. The frequency of abnormal cardiac axis depends on the type of congenital heart disease.

The Additional Role of the 3-Vessels and Trachea View in Screening for Congenital Heart Disease

Background and Objectives: Although frequent and associated with high mortality and morbidity rate, congenital heart disease (CHD) has a suboptimal prenatal detection rate, with significant variation according to the scanning protocol. The aim of this study was to evaluate the role of the 3-vessels and trachea view (3VT) in detecting CHD, with or without the use of Color Doppler, with an emphasis on major CHD. Materials and Methods: We performed a retrospective study on 1596 unselected pregnant patients presenting at 11–37 weeks of gestation for a routine anomaly scan. We selected all CHD cases, and we analyzed the performance of the 4-chamber (4C) and 3VT view in detecting CHD. Results: A total of 46 fetuses with CHD were identified, yielding a 2.86% overall incidence, and 0.87% for major CHD. Grayscale 4C detected 47.8% of all CHD, going up to 71.7% by adding grayscale 3VT, with no major CHD remaining undetected by combining grayscale 4C and 3VT. Conclusions: Grayscale 4C and 3VT views are effective in detecting major CHD, thus proving their utility even in a low resource setting.

Postmortem 9.4-T MRI for Fetuses With Congenital Heart Defects Diagnosed in the First Trimester

Objective

To evaluate the feasibility of 9. 4-T postmortem MRI (pm-MRI) for assessment of major congenital heart defects (CHD) cases terminated in the early stage of gestation.

Methods

Fetuses with CHD detected by the detailed first-trimester ultrasound scan and terminated before 18 gestational weeks were recruited between January 2018 and June 2020. All fetuses were offered 9.4-T pm-MRI examinations and those terminated over 13+6 weeks were offered conventional autopsies simultaneously. Findings of pm-MRI were compared with those of conventional autopsy and prenatal ultrasound.

Results

A total of 19 fetuses with major CHD were analyzed, including 6 cases of the atrioventricular septal defect, 5 cases of Tetralogy of Fallot, 3 cases of hypoplastic left heart syndrome, 1 case of tricuspid atresia, 1 case of transposition of the great arteries, 1 case of severe tricuspid regurgitation, and 2 cases of complex CHD. Pm-MRI had concordant findings in 73.7% (14/19) cases, discordant findings in 15.8% (3/19) cases, and additional findings in 10.5% (2/19) cases when compared with prenatal ultrasound. Pm-MRI findings were concordant with autopsy in all 8 CHD cases terminated over 13+6 weeks.

Conclusion

It is feasible to exhibit the structure of fetal heart terminated in the first trimester clearly on 9.4-T pm-MRI with an optimized scanning protocol. High-field pm-MRI could provide medical imaging information of CHD for those terminated in the early stage of gestation, especially for those limited by conventional autopsy.

First-trimester ultrasound detection of fetal heart anomalies: systematic review and meta-analysis

OBJECTIVES

To determine the diagnostic accuracy of ultrasound at 11-14 weeks' gestation in the detection of fetal cardiac abnormalities and to evaluate factors that impact the detection rate.

METHODS

This was a systematic review of studies evaluating the diagnostic accuracy of ultrasound in the detection of fetal cardiac anomalies at 11-14 weeks' gestation, performed by two independent reviewers. An electronic search of four databases (MEDLINE, EMBASE, Web of Science Core Collection and The Cochrane Library) was conducted for studies published between January 1998 and July 2020. Prospective and retrospective studies evaluating pregnancies at any prior level of risk and in any healthcare setting were eligible for inclusion. The reference standard used was the detection of a cardiac abnormality on postnatal or postmortem examination. Data were extracted from the included studies to populate 2 × 2 tables. Meta-analysis was performed using a random-effects model in order to determine the performance of first-trimester ultrasound in the detection of major cardiac abnormalities overall and of individual types of cardiac abnormality. Data were analyzed separately for high-risk and non-high-risk populations. Preplanned secondary analyses were conducted in order to assess factors that may impact screening performance, including the imaging protocol used for cardiac assessment (including the use of color-flow Doppler), ultrasound modality, year of publication and the index of sonographer suspicion at the time of the scan. Risk of bias and quality assessment were undertaken for all included studies using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool.

RESULTS

The electronic search yielded 4108 citations. Following review of titles and abstracts, 223 publications underwent full-text review, of which 63 studies, reporting on 328 262 fetuses, were selected for inclusion in the meta-analysis. In the non-high-risk population (45 studies, 306 872 fetuses), 1445 major cardiac anomalies were identified (prevalence, 0.41% (95% CI, 0.39-0.43%)). Of these, 767 were detected on first-trimester ultrasound examination of the heart and 678 were not detected. First-trimester ultrasound had a pooled sensitivity of 55.80% (95% CI, 45.87-65.50%), specificity of 99.98% (95% CI, 99.97-99.99%) and positive predictive value of 94.85% (95% CI, 91.63-97.32%) in the non-high-risk population. The cases diagnosed in the first trimester represented 63.67% (95% CI, 54.35-72.49%) of all antenatally diagnosed major cardiac abnormalities in the non-high-risk population. In the high-risk population (18 studies, 21 390 fetuses), 480 major cardiac anomalies were identified (prevalence, 1.36% (95% CI, 1.20-1.52%)). Of these, 338 were detected on first-trimester ultrasound examination and 142 were not detected. First-trimester ultrasound had a pooled sensitivity of 67.74% (95% CI, 55.25-79.06%), specificity of 99.75% (95% CI, 99.47-99.92%) and positive predictive value of 94.22% (95% CI, 90.22-97.22%) in the high-risk population. The cases diagnosed in the first trimester represented 79.86% (95% CI, 69.89-88.25%) of all antenatally diagnosed major cardiac abnormalities in the high-risk population. The imaging protocol used for examination was found to have an important impact on screening performance in both populations (P < 0.0001), with a significantly higher detection rate observed in studies using at least one outflow-tract view or color-flow Doppler imaging (both P < 0.0001). Different types of cardiac anomaly were not equally amenable to detection on first-trimester ultrasound.

CONCLUSIONS

First-trimester ultrasound examination of the fetal heart allows identification of over half of fetuses affected by major cardiac pathology. Future first-trimester screening programs should follow structured anatomical assessment protocols and consider the introduction of outflow-tract views and color-flow Doppler imaging, as this would improve detection rates of fetal cardiac pathology. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.