22q11 deletions in fetuses with malformations of the outflow tracts or interruption of the aortic arch: impact of additional ultrasound signs

Prenatal cardiac findings and 22q11.2 deletion syndrome: Fetal detection and evaluation

Clinical features of 22q11.2 microdeletion syndrome (22q11.2DS) are highly variable between affected individuals and frequently include a subset of conotruncal and aortic arch anomalies. Many are diagnosed with 22q11.2DS when they present as a fetus, newborn or infant with characteristic cardiac findings and subsequently undergo genetic testing. The presence of an aortic arch anomaly with characteristic intracardiac anomalies increases the likelihood that the patient has 22q11.2 DS, but those with an aortic arch anomaly and normal intracardiac anatomy are also at risk. It is particularly important to identify the fetus at risk for 22q11.2DS in order to prepare the expectant parents and plan postnatal care for optimal outcomes. Fetal anatomy scans now readily identify aortic arch anomalies (aberrant right subclavian artery, right sided aortic arch or double aortic arch) in the three-vessel tracheal view. Given the association of 22q11.2DS with aortic arch anomalies with and without intracardiac defects, this review highlights the importance of recognizing the fetus at risk for 22q11.2 deletion syndrome with an aortic arch anomaly and details current methods for genetic testing. To assist in the prenatal diagnosis of 22q11.2DS, this review summarizes the seminal features of 22q11.2DS, its prenatal presentation and current methods for genetic testing.

Associated congenital anomalies and genetic anomalies in fetuses with isolated and non-isolated aberrant right subclavian artery

OBJECTIVE

This study's aim was to determine the prevalence of chromosomal anomalies in fetuses with isolated and non-isolated aberrant right subclavian artery (ARSA) and to evaluate its association with other congenital anomalies.

METHODS

From September 2018 to October 2021, 668 ARSA cases were diagnosed by prenatal ultrasound in our hospital; cases with missed visits and a lack of chromosomal findings were excluded and 363 cases were eligible for enrollment. General information, ultrasound presentation, chromosomal findings and pregnancy outcomes were retrospectively analyzed.

RESULTS

Among the 363 cases, 296 were isolated, and 67 were associated with structural abnormalities or soft marker abnormalities. The proportion of fetuses with chromosomal abnormalities in the isolated ARSA group was significantly lower than that in the non-isolated ARSA group (p < .001). In the non-isolated ARSA group, 22 cases were combined with other soft marker abnormalities and 45 cases were combined with structural abnormalities. The most frequent structural abnormality coexisting with ARSA was cardiac malformations (38.81%).

CONCLUSION

The most common combined malformation in ARSA is intracardiac malformation. Isolated ARSA has a low risk of chromosomal abnormalities, so invasive chromosomal testing is not recommended. Non-isolated ARSA has a high incidence of chromosomal abnormalities, so early karyotyping should be recommended.

Perinatal Diagnosis and Management of a Case with Interrupted Aortic Arch, Pulmonary Valve Dysplasia and 22q11.2 Deletion: A Case Report

The 22q11.2 deletion syndrome (22q11.2DS) is the most common chromosomal microdeletion disorder caused by hemizygous microdeletion of the long arm of chromosome 22. It is now known to have a heterogenous presentation that includes multiple additional congenital anomalies and later-onset conditions, such as gastrointestinal and renal abnormalities, autoimmune disease, variable cognitive delays, behavioral phenotypes and psychiatric illness. The purpose of our paper is to present the case of a fetus diagnosed with a complex association of cardiac anomalies: interrupted aortic arch type B, large malalignment-type ventricular septal defect, pulmonary valve dysplasia, and aberrant right subclavian artery for whom the result of genetic testing revealed 22q11.2 deletion. The pregnancy was regularly followed until delivery which took place in Germany so that neonatal cardiac surgery could be performed in an experienced center for cardiac malformations. The distinctivness of our report resides in the fact that it offers a complete image of a case of 22q11.2 deletion syndrome starting from the prenatal diagnosis (and emphasizing on the most relevant sonographic features) and, with parents not opting for termination of pregnancy, ending with the newborn surviving major cardiac surgery, offering thus the possibility to bring into focus postnatal outcome and future expectations in similar cases.

Fetal thymic-thoracic ratio in pregnancies with familial Mediterranean fever

OBJECTIVE

To investigate the thymic-thoracic ratio (TTR) in fetuses of pregnant women with familial Mediterranean fever (FMF).

STUDY DESIGN

This prospective case-control study was conducted with 43 pregnant women diagnosed with FMF and 43 gestational age-matched healthy controls. Pregnant women between 28 and 40 weeks who applied for antenatal care were included in the study. Healthy pregnant women whose age and gestational week matched were defined as the control group.

RESULTS

TTR was significantly lower in the FMF group compared to the control group. The mean TTR value was 0.34 ± 0.03 in the FMF group and 0.36 ± 0.02 in the control group (p < 0.001). TTR was significantly lower in those with FMF duration of ten years or more than those with FMF of less than ten years (p < 0.001). In addition, pregnant women who had an attack during pregnancy had lower TTR (p < 0.001). TTR was significantly associated with white blood cell count, neutrophil count, monocyte count, platelet count, mean platelet volume, C-reactive protein, red cell distribution width, and platelet‑to‑lymphocyte ratio.

CONCLUSION

Besides the inflammation during the FMF attacks, the ongoing subclinical inflammation between the attacks might affect the fetal thymus size. Since TTR is an easily applicable method, it can be used to evaluate fetal inflammation.

Prenatal Screening and Diagnostic Considerations for 22q11.2 Microdeletions

Diagnosis of a chromosome 22q11.2 microdeletion and its associated deletion syndrome (22q11.2DS) is optimally made early. We reviewed the available literature to provide contemporary guidance and recommendations related to the prenatal period. Indications for prenatal diagnostic testing include a parent or child with the 22q11.2 microdeletion or suggestive prenatal screening results. Definitive diagnosis by genetic testing of chorionic villi or amniocytes using a chromosomal microarray will detect clinically relevant microdeletions. Screening options include noninvasive prenatal screening (NIPS) and imaging. The potential benefits and limitations of each screening method should be clearly conveyed. NIPS, a genetic option available from 10 weeks gestational age, has a 70-83% detection rate and a 40-50% PPV for most associated 22q11.2 microdeletions. Prenatal imaging, usually by ultrasound, can detect several physical features associated with 22q11.2DS. Findings vary, related to detection methods, gestational age, and relative specificity. Conotruncal cardiac anomalies are more strongly associated than skeletal, urinary tract, or other congenital anomalies such as thymic hypoplasia or cavum septi pellucidi dilatation. Among others, intrauterine growth restriction and polyhydramnios are additional associated, prenatally detectable signs. Preconception genetic counselling should be offered to males and females with 22q11.2DS, as there is a 50% risk of transmission in each pregnancy. A previous history of a de novo 22q11.2 microdeletion conveys a low risk of recurrence. Prenatal genetic counselling includes an offer of screening or diagnostic testing and discussion of results. The goal is to facilitate optimal perinatal care.

Prenatal diagnosis of aberrant right subclavian artery: a literature review

The primary aim of this review is to estimate the prevalence of ARSA both in euploid fetuses as well as in fetuses with Down Syndrome. Secondary objectives were to estimate the association of ARSA with cardiac anomalies and chromosomal defects, especially trisomy 21 and 22q11 deletion (DiGeorge Syndrome). The incidence of ARSA in normal population varies from 0.35% to 3.5%, based on different studies. Since the first reported association between ARSA and trisomy 21 in 2015 until today, several studies have emerged to confirm different degrees of this correlation. Indeed, ARSA appears to be a clinically useful prenatal ultrasound marker for trisomy 21. Particularly, most recent studies concluded that ARSA as a non-isolated finding can be used as screening for Down syndrome. However, when ARSA is an isolated finding, various studies proved that there is no significant correlation with Down syndrome. Apart from these, ARSA appears to be associated with other chromosomal abnormalities, such as 22q11 deletion, cardiac defects and other morphological anomalies. As a conclusion ARSA should be characterized as isolated or non-isolated, as the non - isolated ARSA appears to be a clinically useful marker of Down syndrome and thus, additional testing is required when diagnosed.

Fallot type of absent pulmonary valve syndrome - A case report

Absent pulmonary valve syndrome (APVS) is a rare congenital cardiac malformation characterized by absent, dysplastic, or rudimentary pulmonary valve leaflets in association with other cardiac anomalies. It has an incidence of 3-6% in cases of tetralogy of Fallot (TOF) and 0.2-0.4% of live-born infants with congenital heart disease (CHD). Absent pulmonary valve leads to dilated main pulmonary artery; presenting as a pulsatile, paracardiac cystic lesion on antenatal ultrasound (USG). We report a case of this rare anomaly in association with ventricular septal defect (VSD), TOF, and left axis deviation of heart detected at 23 weeks of gestation.

Initial validation of the diagnostic performance of Thymic-Thoracic Ratio as a marker of conotruncal abnormalities and for prediction of surgical prognosis in fetuses without 22q11.2 deletion

AIM

The present study aimed to perform an initial validation of the Thymic-Thoracic Ratio as a sonographic marker of conotruncal defects in non-syndromic fetuses and to assess the possible correlation between the grade of thymic hypoplasia and the severity of conotruncal defects.

METHODS

The study was conducted between January and June 2018 on singleton pregnant women who underwent fetal echocardiography at our institution. Fetuses with a diagnosis of conotruncal defects without 22q11.2 deletion composed the study group, while healthy appropriate for gestational age fetuses composed the control group. The Thymic-Thoracic Ratio was measured in all included fetuses and compared between the study and control group. A ROC curve analysis to evaluate the diagnostic performance of Thymic-Thoracic Ratio toward the diagnosis of conotruncal defects was performed, with determination of sensitivity, specificity, PPV, NPV, positive likelihood ratio, and negative likelihood ratio. The severity of conotruncal defects was defined with the Aristotle score in each newborn who underwent a surgical operation. The correlation between Thymic-Thoracic Ratio and Aristotle score was assessed.

RESULTS

During the study period, 23 fetuses with conotruncal defects without 22q11.2 deletion constituted the study group, and 67 healthy appropriate for gestational age fetuses were included in the control group. The T-T ratio of the study group was significantly lower than the control group (0.32 ± 0.08 vs. 0.41 ± 0.08, p < .001). The ROC curve analysis showed an AUC of 0.80 (95% CI, 0.71-0.89, p < .001) and a T-T ratio cutoff value of 0.35 for the identification of a CTD, with a sensibility of 73.9% (95% CI: 51.6-89.8%), a specificity of 79.1% (95% CI: 67.4-88.1%) a PPV of 54.8% (95% CI: 41.8-67.3%), a NPV of 89.8% (95% CI: 81.5-94.7), a positive likelihood ratio of 3.54 (95% CI 2.09-5.98), and a negative likelihood ratio of 0.33 (95% CI 0.16-0.66). A negative correlation between Aristotle score and T-T ratio was found, with a Kendall-Tau coefficient of -0.41, p = .04.

CONCLUSION

T-T ratio measurement could be useful to identify fetuses at higher risk of conotruncal heart diseases, even without chromosomic deletion, with a cutoff of 0.35. Since a lower T-T ratio seems to be related to a worse surgical neonatal prognosis, it could be possible to provide effective counseling and refer patients to high-specialized centers for fetal echocardiography and cardiac surgery.

Fetal cardiac abnormalities: Genetic etiologies to be considered

Congenital heart diseases are a common prenatal finding. The prenatal identification of an associated genetic syndrome or a major extracardiac anomaly helps to understand the etiopathogenic diagnosis. Besides, it also assesses the prognosis, management, and familial recurrence risk while strongly influences parental decision to choose termination of pregnancy or postnatal care. This review article describes the most common genetic diagnoses associated with a prenatal finding of a congenital heart disease and a suggested diagnostic process.

Expanding the fetal phenotype: Prenatal sonographic findings and perinatal outcomes in a cohort of patients with a confirmed 22q11.2 deletion syndrome

22q deletion syndrome (22q11.2DS) is most often correlated prenatally with congenital heart disease and or cleft palate. The extracardiac fetal phenotype associated with 22q11.2DS is not well described. We sought to review both the fetal cardiac and extracardiac findings associated with a cohort of cases ascertained prenatally, confirmed or suspected to have 22q11.2DS, born and cared for in one center. A retrospective chart review was performed on a total of 42 cases with confirmed 22q11.2DS to obtain prenatal findings, perinatal outcomes and diagnostic confirmation. The diagnosis was confirmed prenatally in 67% (28/42) and postnatally in 33% (14/42). The majority (81%) were associated with the standard LCR22A-LCR22D deletion. 95% (40/42) of fetuses were prenatally diagnosed with congenital heart disease. Extracardiac findings were noted in 90% (38/42) of cases. Additional findings involved the central nervous system (38%), gastrointestinal (14%), genitourinary (16.6%), pulmonary (7%), skeletal (19%), facial dysmorphism (21%), small/hypoplastic thymus (26%), and polyhydramnios (30%). One patient was diagnosed prenatally with a bilateral cleft lip and cleft palate. No fetus was diagnosed with intrauterine growth restriction. The average gestational age at delivery was 38 weeks and average birth weight was 3,105 grams. Sixty-two percentage were delivered vaginally and there were no fetal demises. A diagnosis of 22q11.2 deletion syndrome should be considered in all cases of prenatally diagnosed congenital heart disease, particularly when it is not isolated. Microarray is warranted in all cases of structural abnormalities diagnosed prenatally. Prenatal diagnosis of 22q11.2 syndrome can be used to counsel expectant parents regarding pregnancy outcome and guide neonatal management.

Congenital heart diseases and cardiovascular abnormalities in 22q11.2 deletion syndrome: From well-established knowledge to new frontiers

Congenital heart diseases (CHDs) and cardiovascular abnormalities are one of the pillars of clinical diagnosis of 22q11.2 deletion syndrome (22q11.2DS) and still represent the main cause of mortality in the affected children. In the past 30 years, much progress has been made in describing the anatomical patterns of CHD, in improving their diagnosis, medical treatment, and surgical procedures for these conditions, as well as in understanding the underlying genetic and developmental mechanisms. However, further studies are still needed to better determine the true prevalence of CHDs in 22q11.2DS, including data from prenatal studies and on the adult population, to further clarify the genetic mechanisms behind the high variability of phenotypic expression of 22q11.2DS, and to fully understand the mechanism responsible for the increased postoperative morbidity and for the premature death of these patients. Moreover, the increased life expectancy of persons with 22q11.2DS allowed the expansion of the adult population that poses new challenges for clinicians such as acquired cardiovascular problems and complexity related to multisystemic comorbidity. In this review, we provide a comprehensive review of the existing literature about 22q11.2DS in order to summarize the knowledge gained in the past years of clinical experience and research, as well as to identify the remaining gaps in comprehension of this syndrome and the possible future research directions.

Prenatal diagnosis of congenital heart disease: A review of current knowledge

This article reviews important features to improve the diagnosis of congenital heart disease (CHD) by applying ultrasound in prenatal cardiac screening. As low and high-risk pregnancies for CHD are subject to routine obstetric ultrasound, the diagnosis of structural heart defects represents a challenge that involves a team of specialists and subspecialists on fetal ultrasonography. In this review, the images highlight normal anatomy of the heart as well as pathologic cases consistent with cardiac malposition and isomerism, septal defects, pulmonary stenosis/atresia, aortic malformations, hypoplastic left ventricle, conotruncal anomalies, tricuspid dysplasia, and Ebstein’s anomaly, and univentricular heart, among other congenital cardiovascular defects. Anatomical details of most CHD in fetuses were provided by two-dimensional (2D) ultrasound with higher quality imaging, enhancing diagnostic accuracy in a variety of CHD. Moreover, the accuracy of the cardiac defects in obstetrics ultrasound improves the outcome of most CHD, providing planned delivery, aided genetic counseling, and perinatal management.

Chromosomal microarray analysis in fetuses with aberrant right subclavian artery

OBJECTIVE

To evaluate the association between aberrant right subclavian artery (ARSA), with or without additional risk factors for aneuploidy or ultrasound abnormality, and results of chromosomal microarray analysis (CMA).

METHODS

This was a multicenter study of fetuses diagnosed with ARSA that underwent genetic analysis by CMA, all samples being analyzed in the same laboratory. Clinical investigation included nuchal translucency measurement, first- and second-trimester maternal serum screening, early and late second-trimester fetal anatomy scans and fetal echocardiography. Comparative genomic hybridization microarray analysis or single-nucleotide polymorphism array technology was used for CMA of DNA samples obtained from amniotic fluid.

RESULTS

CMA results were available for 63 fetuses with ARSA. In 36 fetuses, ARSA was an isolated finding, and no pathogenic variant was found. Additional ultrasound findings and/or risk factors for aneuploidy were present in 27 fetuses, five of which had pathogenic CMA results. Of these five, trisomy 21 was detected in a fetus with echogenic intracardiac focus (EIF), 22q11 deletion was detected in a fetus with EIF and an increased risk of trisomy 21 of 1:230 from maternal serum screening, 22q11 duplication was detected in a fetus with hypoplastic right kidney and choroid plexus cyst and 22q11 deletion was detected in a fetus with right aortic arch and clubfoot. The fifth fetus had increased nuchal translucency thickness (4 mm) and a ventricular septal defect, and CMA identified both 22q11 deletion and 1q21 duplication.

CONCLUSIONS

In fetuses with isolated ARSA, an invasive procedure for CMA is not indicated. However, CMA is recommended when additional ultrasound abnormalities or risk factors for aneuploidy are observed. The chromosomal findings in four of the five cases with an abnormal CMA result in our study would not have been detected by standard fetal chromosomal testing. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Neuropsychiatric aspects of 22q11.2 deletion syndrome: considerations in the prenatal setting

Most major neuropsychiatric outcomes of concern to families are not detectable by prenatal ultrasound. The introduction of genome-wide chromosomal microarray analysis to prenatal clinical diagnostic testing has increased the detection of pathogenic 22q11.2 deletions, which cause the most common genomic disorder. The recent addition of this and other microdeletions to non-invasive prenatal screening methods using cell-free fetal DNA has further propelled interest in outcomes. Conditions associated with 22q11.2 deletions include intellect ranging from intellectual disability to average, schizophrenia and other treatable psychiatric conditions, epilepsy, and early-onset Parkinson's disease. However, there is currently no way to predict how severe the lifetime expression will be. Available evidence suggests no major role in these neuropsychiatric outcomes for the congenital cardiac or most other structural anomalies that may be detectable on ultrasound. This article provides an outline of the lifetime neuropsychiatric phenotype of 22q11.2 deletion syndrome that will be useful to clinicians involved in prenatal diagnosis and related genetic counselling. The focus is on information that will be most relevant to two common situations: detection of a 22q11.2 deletion in a fetus or newborn, and new diagnosis of 22q11.2 deletion syndrome in a parent without a previous molecular diagnosis. © 2016 John Wiley & Sons, Ltd.

Congenital diaphragmatic hernia in 22q11.2 deletion syndrome

We report the important association of congenital diaphragmatic hernia (CDH) and 22q11.2 deletion syndrome (22q11.2DS). The prevalence of CDH in our cohort of patients with 22q11.2DS is 0.8% (10/1246), which is greater than in the general population (0.025%). This observation suggests that 22q11.2DS should be considered when a child or fetus presents with CDH, in particular when other clinical findings associated with the 22q11.2DS are present, such as congenital cardiac defects. Furthermore, this finding may lead to the identification of an additional locus for diaphragmatic hernia in the general population. © 2016 Wiley Periodicals, Inc.

Pre- and Postnatal Diagnosis of 10p14 Deletion and 22q11.2 Deletion Syndrome and Significance of Non-Cardiac Markers

Congenital heart defect (CHD) is the most common form of birth defects. There is a high association between increased nuchal translucency and CHD in fetuses, and CHD in the antenatal period has a high incidence of 22q11.2 deletion syndrome (22q11.2DS). Apart from 22q11.2DS, the BRUNOL3 gene at 10p14 is also associated with DiGeorge-like features. We studied a total of 110 pre- and postnatal CHD cases with FISH probes. 22q11.2DS was detected in 5 cases and 10p14 deletion in 1 case. Antenatally diagnosed cases of CHD should be investigated by karyotyping and 22q11.2DS testing. Cases with increased nuchal translucency, intrauterine growth retardation, and other non-cardiac malformations because of 22q11.2DS should be screened carefully for thymus dysgenesis. It is also advisable to screen patients referred for 22q11.2DS for a 10p14 deletion, therefore enabling appropriate parental counseling.

The use of imaging technology in the assessment of the fetal inflammatory response syndrome-imaging of the fetal thymus

The fetal inflammatory response syndrome (FIRS) describes a state of extensive fetal multi organ involvement during chorioamnionitis, and is associated with grave implications on perinatal outcome. The syndrome has been linked to the preterm parturition syndrome and is associated with inflammation/infection processes in most of the fetal organs. The fetal thymus, a major organ in the developing immune system involutes during severe neonatal disease and has been shown to be smaller in fetuses with FIRS. Various methods for imaging of the fetal thymus and measurement are described. Currently the only method to diagnose FIRS prenatally is through amniocentesis. We suggest that women who are admitted with preterm labor with intact membranes and those with PPROM should have a detailed sonographic examination of the fetal thymus as a surrogate marker of fetal involvement in intrauterine infection/inflammation processes.

Sonographic Evaluation of the Fetal Thymus Using the Thy-Box Technique Between 13 and 16 Weeks' Gestation

OBJECTIVES

The purposes of this study were to assess the feasibility of fetal thymus measurement between 13 and 16 weeks' gestation, to evaluate the potential difference using color Doppler sonography with the thy-box technique, and to construct normal percentile ranges.

METHODS

This retrospective study included 287 healthy singleton pregnancies. The fetal thymus was shown in an axial plane of the upper mediastinum. Color Doppler imaging was applied to outline the thy-box: ie, the area between the brachiocephalic artery posteriorly and internal mammary arteries laterally. Measurements of the lateral and anteroposterior diameters of the thymus with and without color Doppler imaging were compared.

RESULTS

The thymus was shown in 95% of the cases (273 of 287) between 13 and 16 weeks' gestation. The mean lateral thymus diameter ± SD with color Doppler imaging (5.30 ± 0.7 mm) was significantly longer in comparison to the measurement without color Doppler imaging (5.06 ± 0.8 mm; P < .001), whereas the anteroposterior diameter was significantly shorter (3.19 ± 0.9 versus 3.26 ± 0.8 mm; P = .044). Normal percentiles of thymus measurements for gestational age were constructed.

CONCLUSIONS

The fetal thymus can be clearly and accurately shown as early as 13 weeks' gestation by using the thy-box. Measurements with color Doppler imaging were significantly different from those without and hence are preferable, as color Doppler imaging can delineate the thymus borders more accurately.

Prenatal Diagnosis of Fetal Interrupted Aortic Arch Type A by Two-Dimensional Echocardiography and Four-Dimensional Echocardiography with B-Flow Imaging and Spatiotemporal Image Correlation

BACKGROUND

Fetal interrupted aortic arch (IAA) is a rare cardiac anomaly and its prenatal diagnosis is challenging. The purpose of our report is to evaluate the use of two-dimensional echocardiography (2DE) and 4D echocardiography with B-flow imaging and spatiotemporal image correlation (4D BF-STIC) in detecting IAA type A (IAA-A).

MATERIALS & METHODS

Twenty-three cases of confirmed IAA-A identified by fetal echocardiography were involved in the study. The fetal echocardiography image data were reviewed to analyze the ratio of right ventricle to left ventricle (RV/LV) diameter, the ratio of main pulmonary artery to ascending aorta (MPA/AAO) diameter, and the correlation of RV/LV diameter ratio and size of ventricular septal defect (VSD). 4D BF-STIC was performed in 21 fetuses using the sagittal view (4D BF-STIC-sagittal) and the four-chamber view (4D BF-STIC-4CV) as initial planes of view. An additional 183 normal fetuses were also included in our study. RV/LV and MPA/AAO ratios were calculated and compared with that of IAA-A fetuses. Fetal 2DE, 4D BF-STIC-sagittal, and 4D BF-STIC-4CV were used to visualize the aortic arch and its associated neck vessels. Six subgroups were evaluated according to gestational age.

RESULTS

Fetal 2DE, 4D BF-STIC-sagittal, and 4D BF-STIC-4CV made the correct prenatal diagnosis of IAA-A in 19/23 (82.6%), 14/21 (66.7%), and 19/21 (90.5%) of patients, respectively. A significantly enlarged MPA combined with symmetric ventricles was found in the IAA-A fetuses, while the size of the VSD was negatively correlated with RV/LV ratio. 4D BF-STIC-sagittal and 4D BF-STIC-4CV were better than traditional 2D ultrasound in detecting the aortic arch and neck vessels between 17 and 28 gestational weeks and 29 to 40 gestational weeks in normal fetuses.

CONCLUSION

It is demonstrated that IAA-A could be diagnosed by traditional fetal echocardiography, while 4D technique could better display the anatomic structure and the spatial relationships of the great arteries. Use of volume reconstruction may promote its clinical usage and help prenatal diagnosis.

The role of ultrasound in the diagnosis of fetal genetic syndromes

The use of ultrasound in the prenatal diagnosis of fetal genetic syndromes is rapidly evolving. Advancing technology and new research findings are aiding in the increased accuracy of ultrasound-based diagnosis in combination with other methods of non-invasive and invasive fetal testing. Ultrasound as a screening tool for aneuploidy and other anomalies is increasingly being used throughout pregnancy, beginning in the first trimester. Given the number of recorded syndromes, it is important to identify patterns and establish a strategy for identifying abnormalities on ultrasound. These syndromes encompass a wide range of causes from viral, substance-linked, chromosomal, and other genetic syndromes. Despite the ability of those experienced in ultrasound, it is important to note that not all fetal genetic syndromes can be identified prenatally, and even common syndromes often have no associated ultrasound findings. Here, we review the role of ultrasound in the diagnosis of fetal genetic syndromes.

Variety of prenatally diagnosed congenital heart disease in 22q11.2 deletion syndrome

Objective

To analyze the spectrum of prenatally diagnosed congenital heart disease in a Korean population with 22q11.2 deletion syndrome, and to provide guidelines for screening 22q11.2 deletion prenatally.

Methods

This retrospective study evaluated 1,137 consecutive fetuses that had prenatal genetic testing for 22q11.2 deletion because of suspected congenital heart disease between September 2002 and December 2012, at Asan Medical Center, Seoul, Korea.

Results

Main cardiovascular diseases in the 53 fetuses with confirmed 22q11.2 deletions were tetralogy of Fallot (n = 24, 45%), interrupted aortic arch (n = 10, 19%), ventricular septal defect (n = 5, 9%), double outlet right ventricle (n = 4, 8%), and coarctation of the aorta (n = 4, 8%). Other cardiac defects were rarely associated with 22q11.2 deletion. One fetus had persistent truncus arteriosus, one had aortic stenosis, and one had hypoplastic right heart syndrome. Two fetuses had normal intracardiac anatomy with an isolated right aortic arch, and one had an isolated bilateral superior vena cava.

Conclusion

A variety of congenital heart diseases were seen during the prenatal period. Conotruncal cardiac defects except transposition of great arteries were strongly associated with 22q11.2 deletion. When such anomalies are diagnosed by fetal echocardiography, genetic testing for 22q11.2 deletion should be offered. Even if less frequent deletion-related cardiac defects are detected, other related anomalies, such as thymic hypoplasia or aplasia, should be evaluated to rule out a 22q11.2 deletion.

Microarray-based prenatal diagnosis for the identification of fetal chromosome abnormalities

The goal of prenatal cytogenetic testing is to provide reassurance to the couple seeking testing for their pregnancy, identify chromosome abnormalities in the fetus, if present, and provide treatments and medical management for affected babies. Cytogenetic analysis of banded chromosomes has been the standard for identifying chromosome abnormalities in the fetus for over 40 years. With chromosome analysis, whole chromosome aneuploidies and large structural rearrangements can be identified. The sequencing of the human genome has provided the resources to develop molecular tools that allow higher resolution observations of human chromosomes. The future holds the promise of sequencing that may identify chromosomal imbalances and deleterious single nucleotide variants. This review will focus on the use of genomic microarrays for the testing and identification of chromosome anomalies in prenatal diagnosis and will discuss the future directions of fetal testing.

22q11.2 deletions in patients with conotruncal defects: data from 1,610 consecutive cases

The 22q11.2 deletion syndrome is characterized by multiple congenital anomalies including conotruncal cardiac defects. Identifying the patient with a 22q11.2 deletion (22q11del) can be challenging because many extracardiac features become apparent later in life. We sought to better define the cardiac phenotype associated with a 22q11del to help direct genetic testing. 1,610 patients with conotruncal defects were sequentially tested for a 22q11del. The counts and frequencies of primary lesions and cardiac features were tabulated for those with and those without a 22q11del. Logistic regression models investigated cardiac features that predicted deletion status in tetralogy of Fallot (TOF). Deletion frequency varied by primary anatomic phenotype. Regardless of the cardiac diagnosis, a concurrent aortic arch anomaly (AAA) was strongly associated with deletion status [odds ratio (OR), 5.07; 95 % confidence interval (CI), 3.66-7.04]. In the TOF subset, the strongest predictor of deletion status was an AAA (OR, 3.14; 95 % CI 1.87-5.27; p < 0.001), followed by pulmonary valve atresia (OR, 2.03; 95 % CI 1.02-4.02; p = 0.04). Among those with double-outlet right ventricle and transposition of the great arteries, only those with an AAA had a 22q11del. However, 5 % of the patients with an isolated conoventricular ventricular septal defect and normal aortic arch anatomy had a 22q11del, whereas no one with an interrupted aortic arch type A had a 22q11del. A subset of patients with conotruncal defects are at risk for a 22q11del. A concurrent AAA increases the risk regardless of the intracardiac anatomy. These findings help to direct genetic screening for the 22q11.2 deletion syndrome in the cardiac patient.

Thymic-thoracic ratio in fetuses with trisomy 21, 18 or 13

OBJECTIVES

To assess thymic size expressed as the thymic-thoracic ratio (TT-ratio) in fetuses with trisomy 21, 18 or 13.

METHODS

The TT-ratio, the quotient of the anteroposterior thymic and the intrathoracic mediastinal diameter, was measured in 65 trisomic fetuses between 15 and 36 weeks' gestation, including 30 cases with trisomy 21, 19 with trisomy 18 and 16 with trisomy 13. In addition these 65 fetuses were divided into two groups, according to whether they showed growth that was appropriate-for-gestational age (AGA) (n = 39) or intrauterine growth restriction (IUGR) (n = 26). Measurements were compared with reference ranges from 302 normal fetuses.

RESULTS

The TT-ratio was low in 27.7% (n = 18) of the 65 fetuses with aneuploidy. In comparison to normal fetuses (mean TT-ratio, 0.44), those with trisomy 18 or 21 had a significantly smaller TT-ratio (mean, 0.38 (P < 0.001) and 0.40 (P < 0.05), respectively), while those with trisomy 13 did not (mean, 0.43). These values were not as low as those observed previously in fetuses with del.22q11, suggesting a mechanism involving accelerated thymic involution rather than primary thymic hypoplasia. Furthermore, the TT-ratio was significantly lower than normal in both AGA (P < 0.05) and IUGR (P < 0.001) fetuses.

CONCLUSION

Fetuses with trisomy 18 or 21, but not trisomy 13, have a small thymus, suggesting accelerated thymic involution in utero. IUGR may contribute to the reduced thymic size in trisomy 18 fetuses. Trisomy 21 fetuses seem to have additional factors leading to a small thymus which could be a possible confirmation of the reduced immune response observed in fetuses and neonates with Down syndrome.

The three-vessel view in the fetal mediastinum in the diagnosis of interrupted aortic arch

Interruption of the aortic arch (IAA) is difficult to detect and diagnose in utero. However, prenatal diagnosis may be beneficial because IAA is rapidly fatal (median age, 10 d) if left uncorrected. Our objective was to review the direct and indirect echocardiographic markers associated with IAA, focusing on the importance of the three-vessel view (3VV), which is obtained during routine ultrasound examination to rule out malformations. We analyzed the fetal echocardiograms of nine fetuses and compared them with 56 normal controls. In each fetus, there was a large discrepancy between the diameter of the larger, dilated pulmonary artery (PA) and smaller, narrow aortic arch (Ao). The calculated ratio of PA/Ao in fetuses with IAA was 2.6 ± 0.4 compared with 1.1 ± 0.09 in normal controls (p < 0.0001). The calculated ratio of PA/Ao in fetuses with IAA type A was 2.1 ± 0.09 and IAA type B 2.9 ± 0.2 (p = 0.0007). Discrepancy between PA/Ao diameters should raise the suspicion of aortic arch anomalies and a large discrepancy is a nearly pathognomonic sign of IAA type B.

Síndrome de deleção 22q11.2 e cardiopatias congênitas

OBJETIVO: Revisar as características clínicas, etiológicas e diagnósticas da síndrome de deleção 22q11 e sua associação com as cardiopatias congênitas. FONTES DOS DADOS: Foram pesquisados artigos científicos presentes nos portais Medline, Lilacs e SciELO, utilizando-se descritores específicos como "22q11", "DiGeorge syndrome", "velocardiofacial syndrome", "congenital heart defects" e "cardio-vascular malformations". O período adotado para a revisão foi de 1980 a 2009. SÍNTESE DOS DADOS: As malformações cardíacas são os defeitos congênitos observados mais frequentemente ao nascimento e representam um problema importante de Saúde Pública. Dentre suas principais causas conhecidas destaca-se a síndrome de deleção 22q11, também chamada de síndrome de DiGeorge, síndrome velocardiofacial e CATCH22. Trata-se de uma doença autossômica domi-nante caracterizada por um fenótipo altamente variável, o que dificulta em muito seu reconhecimento clínico. Além disso, a maior parte dos pacientes apresenta uma microdeleção identificada principalmente por técnicas de citogenética molecular, como a hibridização in situ fluorescente, pouco disponíveis em nosso meio. De forma similar a outras síndromes, a síndrome de deleção 22q11 associa-se a certos defeitos cardíacos específicos, no caso os do tipo conotruncal. Apesar disso, não há ainda na literatura um consenso sobre quais os pacientes com car-diopatia congênita que deveriam ser investigados para a síndrome de deleção 22q11. CONCLUSÕES: Cardiologistas e cirurgiões cardíacos, espe-cialmente pediátricos, devem estar cientes das peculiaridades e dos cuidados dispensados à síndrome de deleção 22q11. Os indivíduos com a síndrome apresentam comumente alterações envolvendo vários sistemas, o que pode levar a dificuldades e a complicações durante seu manejo clínico e cirúrgico.

The thymic-thoracic ratio in fetal heart defects: a simple way to identify fetuses at high risk for microdeletion 22q11

OBJECTIVES

To establish reference ranges for the fetal thymic-thoracic ratio (TT-ratio) and to compare results with those from fetuses with congenital heart defects (CHD) with and without microdeletion 22q11 (del.22q11), a condition known to be associated with a hypoplastic thymus.

METHODS

TT-ratio was defined as the quotient of the anteroposterior thymic to the intrathoracic mediastinal diameters measured in the three vessels and trachea view. This ratio was measured in a prospective cross-sectional study of 302 normal healthy fetuses between 15 and 39 weeks' gestation. The study group comprised two groups: one group (CHDn) consisted of 90 fetuses with CHD and a normal karyotype with no del.22q11 and the other group (CHD(22)) included 20 fetuses with CHD and a normal karyotype but with proven del.22q11.

RESULTS

The TT-ratio of the normal fetuses did not show any statistically significant change during gestation, with a mean value of 0.44. The values of all 90 fetuses of the CHDn group were within the normal range and no different from normal fetuses. However, 19 of the 20 (95%) fetuses in the CHD(22) group had a significantly smaller TT-ratio (P < 0.001) compared with both the CHDn group and the normal fetuses, having a mean value of 0.25.

CONCLUSIONS

The TT-ratio is reliable and easy to obtain during fetal echocardiography. Fetuses with CHD and a low TT-ratio can be considered at high risk of having microdeletion del.22q11.

Prenatal and postnatal diagnosis of 22q11.2 deletion syndrome

Microdeletion of chromosome 22q11.2, the most common human deletion syndrome encompasses a wide spectrum of abnormalities. Many clinical or ultrasonographic findings may support deletion studies, either in utero or in the post-natal period. The objective of our study was to evaluate the circumstances of 22q11.2 deletion diagnosis in a single centre of genetics during a 12 years period. Testing for 22q11.2 deletion was performed in 883 cases. Congenital heart defect was the most common reason for referral. An antenatal 22q11.2 microdeletion was detected in 8 fetuses (4.7%) among 169 pregnancies, all presenting conotruncal anomalies. In one case prenatal diagnosis led to the identification of the deletion in the mildly affected father and had negative impact on the family. During the same period, postnatal 22q11.2 DS was diagnosed in 81 out of 714 patients aged from birth to 42 years (11.3%) (p = 0.02). A CHD was present in 37 (45.7%). This figure is significantly lower than the 75% commonly reported. These results suggest that deletion studies could be justifiable in fetuses with non-cardiac prenatal sonographic findings that have been reported in association with 22q11.2 DS. However, as most of these malformations are rather common and non specific, systematic 22q11.2 testing is not justifiable. In such cases, careful cardiac and thymus examination could provide additional clues for 22q11.2 testing. In addition parents should be given accurate information before antenatal or postnatal testing, including the wide variability of the clinical phenotype, the impossibility to establish a precise prognosis concerning psychomotor development and psychiatric risks.

Fetal interrupted aortic arch: 2D-4D echocardiography, associations and outcome

OBJECTIVES

To analyze fetal two-dimensional (2D) echocardiographic characteristics of interrupted aortic arch (IAA) and its different types, to explore whether the use of 4D ultrasound with B-flow imaging and spatiotemporal image correlation (STIC) can improve prenatal diagnostic accuracy, and to describe associations and outcome.

METHODS

The study comprised IAA fetuses examined exclusively by 2D conventional echocardiography during the period from 1994 to 2003, and those identified by conventional echocardiography and examined further by 4D ultrasound with B-flow imaging and STIC during the period January 2004 to July 2008, identified among fetuses examined at two referral centers for congenital heart defects (CHD). Postnatal follow-up was available in all cases. Karyotyping and fluorescent in-situ hybridization (FISH) analysis for the DiGeorge critical region (22q11.2) were performed in all cases.

RESULTS

Twenty-two cases of isolated IAA (15 Type B and seven Type A, seven and three of which, respectively, underwent B-flow imaging and STIC) were detected among 2520 cases of fetal CHD. In seven of the 15 Type B cases, a right subclavian artery arose anomalously (ARSA). 2D echocardiography failed to distinguish the type of IAA in only two cases and the ARSA in five of the seven cases. B-flow imaging and STIC successfully identified IAA types in all 10 cases examined and clearly visualized the origin and course of the ARSA, including cervical ones. FISH detected 22q11.2 microdeletion in 10 of the 15 Type B cases and an unusual association with Type A in one of the seven cases. Fetal/neonatal outcome included: eight terminations of pregnancy, one intrauterine death and four postoperative deaths in the neonatal period, and nine neonates were alive after surgery at a mean follow-up time of 58 months (range, 4 months-13 years).

CONCLUSION

Our results confirm the feasibility of prenatal characterization of IAA and its different types based on 2D echocardiographic examination, albeit with some limitations in the thorough assessment. 4D ultrasound with B-flow imaging and STIC can apparently facilitate visualization and detailed examination of the anatomical features of the IAA types, including visualization of the neck vessels, thus supplying additional information with respect to 2D sonography. As for the known association with microdeletion 22q11.2, our data indicate that Types A and B are distinct, there being a close association only with IAA Type B.

Great vessel development requires biallelic expression of Chd7 and Tbx1 in pharyngeal ectoderm in mice

Aortic arch artery patterning defects account for approximately 20% of congenital cardiovascular malformations and are observed frequently in velocardiofacial syndrome (VCFS). In the current study, we screened for chromosome rearrangements in patients suspected of VCFS, but who lacked a 22q11 deletion or TBX1 mutation. One individual displayed hemizygous CHD7, which encodes a chromodomain protein. CHD7 haploinsufficiency is the major cause of coloboma, heart defect, atresia choanae, retarded growth and development, genital hypoplasia, and ear anomalies/deafness (CHARGE) syndrome, but this patient lacked the major diagnostic features of coloboma and choanal atresia. Because a subset of CHARGE cases also display 22q11 deletions, we explored the embryological relationship between CHARGE and VCSF using mouse models. The hallmark of Tbx1 haploinsufficiency is hypo/aplasia of the fourth pharyngeal arch artery (PAA) at E10.5. Identical malformations were observed in Chd7 heterozygotes, with resulting aortic arch interruption at later stages. Other than Tbx1, Chd7 is the only gene reported to affect fourth PAA development by haploinsufficiency. Moreover, Tbx1+/-;Chd7+/- double heterozygotes demonstrated a synergistic interaction during fourth PAA, thymus, and ear morphogenesis. We could not rescue PAA morphogenesis by restoring neural crest Chd7 expression. Rather, biallelic expression of Chd7 and Tbx1 in the pharyngeal ectoderm was required for normal PAA development.

Diameter of the normal fetal thymus on ultrasound

OBJECTIVE

To present the normative data of the transverse diameter of the developing fetal thymus.

METHODS

In this prospective study, the maximum transverse diameter of the thymus was measured by one sonologist in 376 normal fetuses between 19 and 38 weeks of gestation. We assessed the relationship of the transverse thymic diameter with gestational age (GA), biparietal diameter, femur length and abdominal circumference using general linear regression modeling. The predicted mean and 95% reference range of thymic diameter at each GA were calculated from the regression equation.

RESULTS

Measurements of the transverse diameter were possible in 352 of the 376 (94%) fetuses. The transverse diameter of the fetal thymus increased with increasing GA and fetal size parameters in a linear manner. The regression equation for transverse diameter of the thymus as a function of GA was: thymic diameter (cm) = 0.15 x GA (weeks) - 1.59 (r(2) = 0.86, P < 0.001).

CONCLUSION

The transverse diameter of the fetal thymus is easy to measure; this study presents normative data.

Cardiac Registry screening for DiGeorge Critical Region deletion using loss of heterozygosity analysis

DiGeorge (DGS), velocardiofacial, and conotruncal anomaly face syndromes comprise a phenotypic spectrum that is associated with a submicroscopic 22q11.2 deletion in the majority of cases. These syndromes variably express complex congenital heart disease, cellular immune deficits, hypocalcemia, craniofacial anomalies, and learning disabilities. This retrospective study correlates the presence of a deletion in this region with autopsy and clinical findings in a cohort of patients selected from the Cardiac Registry at Boston Children's Hospital. DNA was extracted from formalin-fixed paraffin-embedded cardiac tissue sampled from 189 patients with conotruncal anomalies. Polymerase chain reaction (PCR) was performed using 4 fluorescently labeled oligonucleotide primer pairs for unique short tandem repeat polymorphisms in the DGS critical region. The PCR products were analyzed for loss of heterozygosity (LOH), and a deletion was assumed when at least 3 consecutive loci demonstrated homozygosity. Of the 189 cases, 16 (8%) met our criteria for LOH and were assumed to have a deletion. These patients included 6 (35%) of 17 patients diagnosed clinically with DGS prior to death. Of the 10 non-DGS patients with LOH, 4 had aortic atresia and 3 had tetralogy of Fallot, both frequently seen in DGS. Polymerase chain reaction is a useful screening alternative to fluorescence in situ hydridization for detecting 22q11.2 deletions in archived tissue samples. This study identified a probable deletion in a subset of cases from a cardiac registry with cardiac defects associated with the DGS phenotype.

Novel application of 4D sonography with B-flow imaging and spatio-temporal image correlation (STIC) in the assessment of the anatomy of pulmonary arteries in fetuses with pulmonary atresia and ventricular septal defect

OBJECTIVES

To assess the reliability of two-dimensional gray-scale (2D) and color Doppler echocardiography in the study of the size and anatomy of the central pulmonary arteries and of the sources of pulmonary blood flow in a case series of fetuses with pulmonary atresia and ventricular septal defect (PA-VSD), and to evaluate whether the use of 4D ultrasound with B-flow imaging and spatio-temporal image correlation (STIC) can improve prenatal diagnostic accuracy.

METHODS

The study population comprised a group of seven PA-VSD fetuses that had been examined by 2D and color Doppler echocardiography exclusively, and a group of five additional cases identified initially by conventional echocardiography and examined further by 4D ultrasound, for all of which a thorough postnatal or autopsy study of the size and anatomy of the pulmonary arteries and blood supply was available.

RESULTS

2D and color Doppler echocardiography failed to assess the anatomy of the central pulmonary arteries and the source of the pulmonary blood supply in 33% and 25% of the 12 cases, respectively. 4D ultrasound with B-flow imaging and STIC assessed successfully the anatomy of the pulmonary arteries and the source of pulmonary blood supply in all five fetuses examined.

CONCLUSIONS

The prognosis of PA-VSD is influenced by the anatomy of the pulmonary arteries and the sources of the pulmonary blood supply, and by coexisting extracardiac and genetic anomalies. Our findings, although limited to a small sample size, suggest that 4D echocardiography with B-flow imaging and STIC, unlike 2D ultrasound, can provide thorough visualization of very small vessels and of the arterial blood supply to the lungs of fetuses with PA-VSD. 4D ultrasound may be used in the future to improve and help to detail the diagnosis of other fetal cardiac defects.

Prenatally diagnosed pulmonary atresia with ventricular septal defect: echocardiography, genetics, associated anomalies and outcome

OBJECTIVE

To assess the accuracy of prenatal diagnosis, the association with genetic and extracardiac anomalies, and outcome in fetuses with isolated pulmonary atresia with ventricular septal defect (PA-VSD).

DESIGN AND SETTING

Retrospective study in a tertiary centre for fetal cardiology.

PATIENTS AND OUTCOME MEASURES

Echocardiographic video recordings of 27 consecutive fetuses with PA-VSD were reviewed for: (1) intracardiac anatomy; (2) presence of confluence and size of the branch pulmonary arteries; (3) source of pulmonary blood supply; and (4) side of the aortic arch. Postmortem and postnatal data were added. Karyotyping was performed in 25 patients and, in 23 of these, fluorescent in situ hybridisation to identify 22q11.2 deletion.

RESULTS

PA-VSD was correctly diagnosed in 19 of 21 patients (90%) with postnatal or autopsy confirmation of diagnosis. Central pulmonary arteries were correctly identified in 79% (15/19), the source of pulmonary blood supply in 62% (13/21) and major aortopulmonary collateral arteries in 44% (4/9). Aneuploidy was detected in 4 of 25 patients (16%) and 22q11.2 deletion in 6 of 23 patients (26%). Five of 27 patients (19%) had extracardiac anomalies. Eleven pregnancies were interrupted. Eleven of 16 liveborn babies survived. Neonatal survival was 15 of 16 (94%, 95% confidence interval (CI) 70 to 100), one-year survival was 9 of 12 (75%, 95% CI 43 to 95) and two-year survival was 5 of 9 (56%, 95% CI 21 to 86).

CONCLUSION

PA-VSD can be diagnosed by fetal echocardiography with a high degree of accuracy. However, it can be difficult to determine the morphology of the central pulmonary arteries and to locate the source of pulmonary blood supply. In most liveborn infants, complete surgical repair can be achieved.

Differential detection of deletion 22q11.2 syndrome by specialty and indication

This study identified cytogenetic abnormalities in a population screened for deletion 22q11.2 syndrome (D22S) by fluorescence in situ hybridization (FISH) and G-banding and correlated these abnormalities to referring specialty and submitted indications. Requests for the D22S FISH assay were retrospectively reviewed over a 29-month period in our institution. Positive test results for D22S FISH and other abnormalities found by other FISH assays and G-banding were correlated to submitting specialist and indication. Thirteen medical services ordered D22S FISH testing on 297 patients over 29 months. The detection rate for all cytogenetic aberrations was 9.4% (28 of 297) including 5.4% (16 of 297) for D22S detection by FISH and 2.7% (8 of 297) for detection of additional cytogenetic anomalies by G-banding cytogenetics. Sixty-six of 297 patients negative by D22S FISH and G-banding were screened using other FISH assays and 3 of 47 (6.4%) patients screened using subtelomeric probes were positive for deletion and 1 of 3 (33%) patients screened for Prader-Willi syndrome was positive for deletion. Pediatric geneticists requested 53.9% (160 of 297) of the tests, yielding 60.7% (17 of 28) of positive test results. Tetralogy of Fallot and developmental delay were the indications associated with the most positive test results. In our institution, pediatric geneticists identify the largest spectrum of indications with D22S and appear most aware of the association of developmental delay with D22S. Performing conventional cytogenetics and other FISH assays, in addition to FISH for D22S, is important because there is considerable overlap between D22S and the phenotype of several other syndromes.

Characteristics, associations and outcome of absent pulmonary valve syndrome in the fetus

OBJECTIVES

To assess in a population of 21 fetuses diagnosed with absent pulmonary valve syndrome (APVS) the accuracy of prenatal diagnosis, the incidence of extracardiac and chromosomal anomalies and the perinatal outcome.

METHODS

This was a retrospective observational study of 21 fetuses with a confirmed diagnosis of APVS. All of them underwent fetal echocardiography and a detailed anatomical scan. Karyotyping was performed in 20/21 cases, with fluorescent in-situ hybridization analysis to detect the 22q11 microdeletion performed in 16/21 cases. The following variables were retrieved from databases and evaluated: indication for referral, gestational age at diagnosis, presence of cardiomegaly, branch pulmonary dilatation, associated anomalies or intrauterine growth restriction, and fetal/neonatal outcome. Autopsy reports and postnatal surgical/medical files were available for confirmation in all cases.

RESULTS

Prenatal diagnosis of APVS proved correct in all cases, with only three cases occurring not in association with tetralogy of Fallot. Additional cardiovascular anomalies were present in five cases (24%). Extracardiac anomalies were found in nine cases (42.8%), and were associated with chromosomal anomalies in five cases (24%). The 22q11 microdeletion was present in 4/16 cases (25%). Fetal/neonatal outcome was as follows: nine terminations of pregnancy, three intrauterine deaths, six postnatal deaths. The remaining three (14.3%) neonates were alive after surgery. Cardiomegaly and marked branch pulmonary dilatation were present in 16 and 15 cases, respectively, and were associated with bronchomalacia in virtually all cases.

CONCLUSIONS

APVS can be reliably diagnosed and characterized prenatally. The association with major chromosomal anomalies or 22q11 microdeletion is consistent with previous findings. The relatively poor survival rate is due to the high rate of terminations, associated genetic anomalies and bronchomalacia. Bronchomalacia is present in the overwhelming majority of cases featuring cardiomegaly and marked branch pulmonary dilatation.