Prenatal findings and pregnancy outcome in fetuses with right and double aortic arch. A 10-year experience at a tertiary center

Prenatal diagnosis in fetal right aortic arch using chromosomal microarray analysis and whole exome sequencing: a Chinese single-center retrospective study

BACKGROUND

Right aortic arch (RAA) is a common congenital aortic arch abnormality. Fetuses with RAA frequently have good outcomes after birth. However, chromosomal abnormalities and genetic syndromes suggest poor prognosis for these patients. So far the underlying genetic etiology is still not identified in most RAA patients based on traditional genetic techniques and a problem is still debated whether fetuses with isolated RAA should be referred for CMA. Our study aims to investigate the genetic etiology of fetuses with right aortic arch (RAA) by chromosomal microarray analysis (CMA) and whole exome sequencing (WES) and evaluate the efficacy of CMA in fetal isolated RAA.

RESULTS

Among these 153 fetuses, 99 (64.7%) with isolated RAA and 54 (35.3%) with non-isolated RAA; 25.5% (39/153) with additional intracardiac anomalies (ICA), and 19.0% (29/153) with extracardiac anomalies (ECA). Tetralogy of Fallot (n = 10) and persistent left superior vena cava (n = 11) are the most common ICA and ECA, respectively. CMA detected 15 clinically significant copy number variations (CNVs) in 14 cases (9.2%); microdeletion of 22q11.21 was the most common pathogenic CNVs (7.8%). The chromosomal abnormalities rate was higher in non-isolated RAA and RAA with ICA groups than in isolated RAA group (16.7% vs. 5.1%; 20% vs. 5.1%, both p < 0.05). From five cases further undergoing WES, a diagnostic variant in MTOR gene (c.7255G > A, de novo) was first reported in prenatal, extending the prenatal manifestation of Smith-Kingsmore syndrome (OMIM: 616638); a clinically relevant variant c.3407A > T in STAG2 was identified, being inherited from the healthy mother. Moreover, the premature birth and termination rates were higher in non-isolated RAA group than in isolated RAA group (11.1% vs. 1.0%; 37.0% vs. 2.0%, both p < 0.01).

CONCLUSIONS

We demonstrate that CMA and WES are useful diagnostic tools for fetal RAA, particularly non-isolated RAA, and all fetuses with RAA should be referred for CMA. The data probably aids in prenatal diagnosis and prenatal counseling of fetal RAA.

Analysis of prognostic risk factors and development of a predictive model for fetuses with right aortic arch with mirror-image branching: a prognostic evaluation method based on ultrasound parameter features

Background

Prenatal ultrasound plays a crucial role in the diagnosis and classification of right aortic arch (AO) with mirror-image branching (RAA-MB). The recent research in this area has primarily focused on qualitative diagnosis, neglecting the quantitative analysis of ultrasound factors that impact RAA-MB outcomes. This study used echocardiography to measure prenatal ultrasound parameters for vascular ring and trachea in fetuses with RAA-MB, employing a nomogram model to evaluate factors influencing their prognosis, thereby providing a comprehensive characterization of potential outcomes.

Methods

A retrospective case-control study was conducted from March 2019 to March 2023. A systematic gathering of prenatal echocardiograms and clinical data was completed for a cohort comprising 92 cases of fetal RAA-MB at the Ultrasound Medicine Center of Gansu Provincial Maternity and Child Care Hospital. Participant recruitment was executed through random selection from among those receiving outpatient medical care. Within the cohort, 42 cases were categorized as fetuses with isolated RAA-MB, while the remaining 50 cases were characterized as fetuses with RAA-MB and associated anomalies. Measurements were taken of the angle between the right AO and the ductus arteriosus (DA) (AO-DA), the distance between the AO and DA, the diameter of AO and DA, and the distance growth rate (DGR) of the AO-DA distance. Additionally, measurements were taken of the tracheal anterior-posterior diameter, tracheal left-right diameter, and tracheal circumference in the three-vessel tracheal view. In the AO view, measurements were taken of the tracheal cross-sectional area (TA) and the vessel ring cross-sectional area (VRA). The relationship between these parameters and the prognosis of fetuses with RAA-MB was assessed using logistic regression analysis. A receiver operating characteristic (ROC) curve was constructed to evaluate the diagnostic performance of the predictive model based on these factors.

Results

The multivariate logistic regression analysis revealed that the independent predictive factors for the prognosis of fetuses with RAA-MB were the AO-DA distance [odds ratio (OR) =0.012], TA (OR =0.401), and VRA (OR =1.103) (all P values <0.001). The area under the ROC curve was 0.891 [95% confidence interval (CI): 0.789-0.914; P<0.001], indicating a high accuracy of the model's predictions.

Conclusions

The AO-DA distance, TA, and VRA are factors that influence the prognosis of fetuses with RAA-MB. The column chart model constructed based on these parameters can effectively provide a reference for predicting the risk of adverse outcomes in fetuses with RAA-MB.

Prenatal diagnosis of right aortic arch: associated anomalies and fetal prognosis according to different subtypes

OBJECTIVES

Right aortic arch (RAA) is a rare anomaly with an incidence of 0.1 % in the adult population and low-risk fetuses. Our aim in this study was to evaluate associated anomalies and conditions according to subtypes.

METHODS

This was a retrospective study examining consecutive pregnancies diagnosed with RAA in our hospital between 2018 and 2022. Fetuses with RAA were divided into three groups, RAA with right-sided ductus arteriosus (RAA-RDA), RAA with left-sided ductus arteriosus (RAA-LDA), and RAA with a double aortic arch (RAA-DAA).

RESULTS

A total of 81 fetuses were diagnosed as having RAA during the study period. The rate of cardiac anomalies (82.8 %) in the RAA-RDA group was higher than in the RAA-LDA (17.6 %) and RAA-DAA (22.2 %) groups (p<0.001). No statistically significant difference was found between the groups in terms of maternal age, diagnosis week, pregnancy outcome, extracardiac anomalies, and genetic anomalies. Three (8 %) of 36 fetuses with isolated RAA who resulted in live birth developed symptoms related to the vascular ring, and one (2.7 %) newborn with RAA-DAA underwent surgery.

CONCLUSIONS

The incidence of cardiac anomalies is high in fetuses with RAA-RDA. Ultrasound examinations should be performed for cardiac anomalies and additional structural anomalies. Vascular ring formation is a rare but important complication due to compression risk to the trachea and esophagus.