Double aortic arch: implications of antenatal diagnosis, differential growth of arches during pregnancy, associated abnormalities and postnatal outcome

OBJECTIVES

To evaluate the prenatal characteristics of double aortic arch (DAA), assess the relative size of the arches and their growth during pregnancy, describe associated cardiac, extracardiac and chromosomal/genetic abnormalities and review postnatal presentation and clinical outcome.

METHODS

This was a retrospective cohort study of all fetuses with a confirmed diagnosis of DAA seen in five specialized referral centers in London, UK, between October 2012 and November 2019. Cases were identified from the hospitals' fetal databases. Fetal echocardiographic findings, intracardiac and extracardiac abnormalities, genetic defects, computed tomography (CT) findings and postnatal clinical presentation and outcome were evaluated.

RESULTS

A total of 79 fetuses with DAA were included. Of those assessed postnatally, 48.6% had an atretic left aortic arch (LAA), while 5.1% had an atretic LAA at the first fetal scan and were misdiagnosed antenatally with right aortic arch (RAA). The LAA was atretic in 55.8% of those who underwent CT. DAA was an isolated abnormality in 91.1% of cases; 8.9% of patients had an additional intracardiac abnormality and 2.5% had both intra- and extracardiac abnormalities. Among the 52 cases that underwent genetic testing, 11.5% had genetic abnormalities and, specifically, the 22q11 microdeletion was identified in 3.8% of patients. At a median follow-up of 993.5 days, 42.5% of patients had developed symptoms of tracheoesophageal compression (5.5% during the first month after birth) and 56.2% had undergone intervention. Statistical analysis using the χ-square test showed no significant relationship between morphology of DAA (patency of both aortic arches vs atretic LAA) and the need for intervention (P = 0.134), development of vascular ring symptoms (P = 0.350) or evidence of airway compression on CT (P = 0.193).

CONCLUSIONS

Most cases of DAA can be diagnosed easily at midgestation, as typically both arches are patent with a dominant RAA at this stage. However, we found that the LAA had become atretic in approximately half of the cases postnatally, supporting the theory of differential growth of the arches during pregnancy. DAA is usually an isolated abnormality; however, thorough assessment is required to exclude associated intra- and extracardiac anomalies and to determine the need for invasive prenatal genetic testing. Postnatally, early clinical assessment is needed and CT scan should be considered, irrespective of the presence of symptoms. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Single left superior vena cava: antenatal diagnosis, associated anomalies and outcomes

OBJECTIVES

To describe the associated cardiac and extracardiac findings and estimate the prevalence of single left superior vena cava (LSVC) among fetuses referred for fetal echocardiography.

METHODS

This was a retrospective case series of fetuses diagnosed with situs solitus and single LSVC at the Brompton Centre for Fetal Cardiology, London, UK, from October 2006 to December 2020. Prenatal and postnatal outcome data were collected. Prenatal diagnosis was based on abnormal vessel alignment at the three-vessel view and/or three-vessel-and-trachea view, showing a vessel to the left of the pulmonary artery (i.e. the LSVC) and absence of the usual vessel to the right of the ascending aorta (i.e. the right superior vena cava), and further visualization of the LSVC draining into the coronary sinus.

RESULTS

Of 19 968 fetal echocardiograms performed during the study period, 34 cases of single LSVC were identified (a prevalence of 0.17%). Of these, 32 pregnancies had a live birth, one was lost to follow-up and one resulted in intrauterine demise. Single LSVC was isolated in 79.4% of cases. No major congenital heart disease was identified. One fetus showed mild isthmus hypoplasia, with no aortic coarctation postnatally. Two fetuses had umbilical vessel abnormalities. A genetic abnormality was found in one case (15q24.1-q24.2 deletion).

CONCLUSIONS

Antenatal diagnosis of single LSVC in the setting of situs solitus is usually a benign isolated finding. Nevertheless, investigation of other cardiac, extracardiac and genetic disorders should be considered. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Urgent neonatal balloon atrial septostomy in simple transposition of the great arteries: predictive value of fetal cardiac parameters

OBJECTIVES

To investigate the impact of abnormal perinatal loading conditions on cardiac geometry and function in term fetuses and neonates with transposition of the great arteries with intact interventricular septum (simple TGA), and to explore the predictive value of fetal cardiac parameters for an urgent balloon atrial septostomy (BAS) after birth.

METHODS

This was a prospective longitudinal follow-up study of women delivering at term, including both uncomplicated pregnancies with normal outcome and pregnancies affected by fetal simple TGA. Conventional, spectral-tissue Doppler and speckle-tracking echocardiographic parameters were obtained within 1 week before delivery and within the first few hours after delivery. Neonates with simple TGA that required urgent BAS were assessed after the procedure and before corrective arterial switch surgery. Cardiac parameters were normalized by cardiac cycle length, ventricular end-diastolic length or end-diastolic dimension, as appropriate. Fetal and neonatal cardiac parameters were compared between simple-TGA cases and controls, and perinatal changes in the simple-TGA group were assessed. Receiver-operating-characteristics (ROC)-curve analysis was used to assess the predictive value of fetal cardiac parameters for urgent BAS after birth in the simple-TGA group.

RESULTS

A total of 67 pregnant women delivering at term were included in the study (54 normal pregnancies and 13 with a diagnosis of fetal simple TGA). Compared with normal term fetuses, term fetuses with simple TGA exhibited more globular hypertrophied ventricles, increased biventricular systolic function and diastolic dysfunction (right ventricular (RV) sphericity index (SI), 0.58 vs 0.54; left ventricular (LV)-SI, 0.55 vs 0.49; combined cardiac output (CCO), 483 vs 406 mL/min/kg; LV torsion, 4.3 vs 3.0 deg/cm; RV isovolumetric relaxation time (IVRT'), 127 vs 102 ms; P < 0.01 for all). Compared with normal neonates, neonates with simple TGA demonstrated biventricular hypertrophy, a more spherical right ventricle and altered systolic and diastolic functional parameters (RV-SI, 0.61 vs 0.43; RV myocardial performance index, 0.47 vs 0.34; CCO, 697 vs 486 mL/min/kg; LV-IVRT', 100 vs 79 ms; RV-IVRT', 106 vs 71 ms; P < 0.001 for all). Paired comparison of neonatal and fetal cardiac indices in the simple-TGA group showed persistence of the fetal phenotype, increased biventricular systolic myocardial contractility and CCO, and diastolic dysfunction (RV systolic myocardial velocity (S'), 0.31 vs 0.24 cm/s; LV-S', 0.23 vs 0.18 cm/s; CCO, 697 vs 483 mL/min/kg; LV torsion, 1.1 vs 4.3 deg/cm; P < 0.001 for all). Several fetal cardiac parameters in term fetuses with simple TGA demonstrated high predictive value for an urgent BAS procedure after birth. Our proposed novel fetal cardiac index, LV rotation-to-shortening ratio, as a potential marker of subendocardial dysfunction, for a cut-off value of ≥ 0.23, had an area under the ROC curve (AUC) of 0.94, sensitivity of 100% and specificity of 83%. For RV/LV end-diastolic area ratio ≥ 1.33, pulmonary-valve-to-aortic-valve-dimension ratio ≤ 0.89, RV/LV cardiac output ratio ≥ 1.38 and foramen-ovale-dimension-to-total-interatrial-septal-length ratio ≤ 0.27, AUC was 0.93-0.98, sensitivity was 86% and specificity was 83-100% for all.

CONCLUSIONS

Simple-TGA fetuses exhibited cardiac remodeling at term with more profound alterations in these cardiac parameters after birth, suggestive of adaptation to abnormal loading conditions and possible adaptive responses to hypoxemia. Perinatal adaptation in simple TGA might reflect persistence of the abnormal parallel arrangement of cardiovascular circulation and the presence of widely patent fetal shunts imposing volume load on the neonatal heart. The fetal cardiac parameters that showed high predictive value for urgent BAS after birth might reflect the impact of late-gestation pathophysiology and progressive hypoxemia on fetal cardiac geometry and function in simple TGA. If these findings are validated in larger prospective studies, detailed cardiac assessment of fetuses with simple TGA near term could facilitate improvements in perinatal management and refinement of the timing of postnatal intervention strategies to prevent adverse pregnancy outcomes. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Left ventricular torsional mechanics in term fetuses and neonates

OBJECTIVE

Left ventricular (LV) torsion is an important aspect of cardiac mechanics and is fundamental to normal ventricular function. The myocardial mechanics of the fetal heart and the changes that occur during the transition to the neonatal period have not been explored previously. The aim of this study was to evaluate perinatal changes in LV torsion and its relationship with myocardial function.

METHODS

This was a prospective study of 36 women with an uncomplicated term pregnancy. Fetal and neonatal conventional, spectral tissue Doppler and two-dimensional (2D) speckle tracking echocardiography were performed a few days before and within hours after delivery to measure cardiac indices including LV rotational parameters derived from short-axis views at the base and apex of the heart. Linear regression analysis was used to examine the relationship between LV rotational parameters and cardiac geometric and functional indices in term fetuses and neonates. Perinatal changes in LV rotational parameters were assessed.

RESULTS

There were three patterns of LV twist in term fetuses: those with reversed-apex-type LV twist had the lowest median values of LV torsion (0.1°/cm), with higher values (1.6°/cm) in those with infant-type LV twist and the highest values (4.4°/cm) in those with adult-type LV twist. LV torsion was associated significantly with cardiac geometric and functional indices. Perinatal evaluation revealed a significant increase in LV torsion following delivery in fetuses exhibiting reversed-apex-type LV twist (increase of 2.8°/cm, P = 0.009) and a significant decrease in those with adult-type LV twist (decrease of 3.2°/cm, P = 0.008).

CONCLUSIONS

This study demonstrates the feasibility of 2D speckle tracking imaging for accurate assessment of rotational cardiac parameters in term fetuses. There are unique perinatal patterns of LV twist that demonstrate different values of LV torsion, which was found to correlate with indices of ventricular geometry and myocardial function. Differences in patterns of LV twist may therefore reflect differences in compensatory myocardial adaptation to the physiological environment/loading conditions in late gestation in fetuses and postnatal cardiac adjustment to the acute loading changes that occur at delivery. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Perinatal changes in fetal cardiac geometry and function in diabetic pregnancy at term

OBJECTIVE

To evaluate the effect of diabetes in pregnancy on fetal and neonatal cardiac geometry and function around the time of delivery.

METHODS

This was a prospective study of 75 pregnant women delivering at term, comprising 54 normal pregnancies and 21 with a diagnosis of pregestational or gestational diabetes mellitus. Fetal and neonatal conventional and spectral tissue Doppler and two-dimensional speckle-tracking echocardiography were performed a few days before and within hours after delivery. Fetal and neonatal cardiac geometry, global myocardial deformation and performance, diastolic and systolic function and left ventricular (LV) torsion were compared between normal pregnancies and those with diabetes, and perinatal changes within the diabetes group were assessed.

RESULTS

Compared with normal pregnancies, diabetic pregnancies demonstrated significant differences in fetal ventricular geometry, myocardial deformation and cardiac function (right ventricular (RV) sphericity index, 0.56 vs 0.65; LV torsion, 2.1 °/cm vs 5.6 °/cm; LV isovolumetric relaxation time, 101 ms vs 115 ms; and RV isovolumetric contraction time, 107 ms vs 119 ms; P < 0.001 for all). Compared with normal pregnancies, diabetic pregnancies demonstrated significant differences in neonatal cardiac parameters (mean RV sphericity index, 0.43 vs 0.55; mean LV torsion, 1.30 °/cm vs 2.78 °/cm; median LV myocardial performance index (MPI'), 0.39 vs 0.51; median RV-MPI', 0.34 vs 0.40; P < 0.01 for all). Paired comparison between fetal and neonatal cardiac indices in diabetic pregnancies demonstrated that delivery resulted in a significant improvement in some, but not all, cardiac indices (mean RV sphericity index, 0.65 vs 0.55; mean LV torsion, 5.60 °/cm vs 2.78 °/cm; median RV-MPI', 0.51 vs 0.40; P < 0.01 for all).

CONCLUSIONS

Compared with normal term fetuses and neonates, those of diabetic women exhibit cardiac indices indicative of myocardial impairment, reflecting a response to a relatively hyperglycemic intrauterine environment with alteration in fetal loading conditions (LV preload deprivation and increased RV afterload) and adaptation to subsequent acute changes in hemodynamic load at delivery. Elucidating mechanisms that contribute to the alterations in perinatal cardiac function in diabetic pregnancy could help in refining management and developing better therapeutic strategies to reduce the risk of adverse pregnancy outcomes. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Perinatal changes in cardiac geometry and function in growth-restricted fetuses at term

OBJECTIVE

To evaluate the effect of fetal growth restriction (FGR) at term on fetal and neonatal cardiac geometry and function.

METHODS

This was a prospective study of 87 pregnant women delivering at term, comprising 54 normally grown and 33 FGR pregnancies. Fetal and neonatal conventional and spectral tissue Doppler and two-dimensional speckle tracking echocardiography were performed a few days before and within hours after birth. Fetal cardiac geometry, global myocardial deformation and performance and systolic and diastolic function were compared between normal and FGR pregnancies before and after birth.

RESULTS

Compared with normally grown fetuses, FGR fetuses exhibited more globular ventricular geometry and poorer myocardial deformation and cardiac function (left ventricular (LV) sphericity index (SI), 0.54 vs 0.49; right ventricular (RV) SI, 0.60 vs 0.54; LV torsion, 1.2 °/cm vs 3.0 °/cm; LV isovolumetric contraction time normalized by cardiac cycle length, 121 ms vs 104 ms; interventricular septum early diastolic myocardial peak velocity/atrial contraction myocardial diastolic peak velocity ratio, 0.60 vs 0.71; P < 0.01 for all). The poorest perinatal outcomes occurred in FGR fetuses with the most impaired cardiac functional indices. When compared with normally grown neonates, FGR neonates showed persistent alteration in cardiac parameters (LV-SI, 0.53 vs 0.50; RV-SI, 0.54 vs 0.44; LV torsion, 1.1 °/cm vs 1.4 °/cm; LV myocardial performance index (MPI'), 0.52 vs 0.42; P < 0.01 for all). Paired comparison of fetal vs neonatal cardiac indices in FGR demonstrated that birth was associated with a significant improvement in some, but not all, cardiac indices (RV-SI, 0.60 vs 0.54; RV-MPI', 0.49 vs 0.39; P < 0.001 for all).

CONCLUSIONS

Compared with normal pregnancies, FGR fetuses and neonates at term exhibit altered cardiac indices indicative of myocardial impairment that reflect adaptation to placental hypoxemia and alterations in hemodynamic load around the time of birth. Elucidating potential mechanisms that contribute to the alterations in perinatal cardiac adaptation in FGR could improve management and aid the development of better therapeutic strategies to reduce the risk of adverse pregnancy outcome. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Fetal hemodynamic response to aortic valvuloplasty and postnatal outcome: a European multicenter study

OBJECTIVE

Fetal aortic stenosis may progress to hypoplastic left heart syndrome. Fetal valvuloplasty (FV) has been proposed to improve left heart hemodynamics and maintain biventricular (BV) circulation. The aim of this study was to assess FV efficacy by comparing survival and postnatal circulation between fetuses that underwent FV and those that did not.

METHODS

This was a retrospective multicenter study of fetuses with aortic stenosis that underwent FV between 2005 and 2012, compared with contemporaneously enrolled natural history (NH) cases sharing similar characteristics at presentation but not undergoing FV. Main outcome measures were overall survival, BV-circulation survival and survival after birth. Secondary outcomes were hemodynamic change and left heart growth. A propensity score model was created including 54/67 FV and 60/147 NH fetuses. Analyses were performed using logistic, Cox or linear regression models with inverse probability of treatment weighting (IPTW) restricted to fetuses with a propensity score of 0.14-0.9, to create a final cohort for analysis of 42 FV and 29 NH cases.

RESULTS

FV was technically successful in 59/67 fetuses at a median age of 26 (21-34) weeks. There were 7/72 (10%) procedure-related losses, and 22/53 (42%) FV babies were delivered at < 37 weeks. IPTW demonstrated improved survival of liveborn infants following FV (hazard ratio, 0.38; 95% CI, 0.23-0.64; P = 0.0001), after adjusting for circulation and postnatal surgical center. Similar proportions had BV circulation (36% for the FV cohort and 38% for the NH cohort) and survival was similar between final circulations. Successful FV cases showed improved hemodynamic response and less deterioration of left heart growth compared with NH cases (P ≤ 0.01).

CONCLUSIONS

We report improvements in fetal hemodynamics and preservation of left heart growth following successful FV compared with NH. While the proportion of those achieving a BV circulation outcome was similar in both cohorts, FV survivors showed improved survival independent of final circulation to 10 years' follow-up. However, FV is associated with a 10% procedure-related loss and increased prematurity compared with the NH cohort, and therefore the risk-to-benefit ratio remains uncertain. We recommend a carefully designed trial incorporating appropriate and integrated fetal and postnatal management strategies to account for center-specific practices, so that the benefits achieved by fetal therapy vs surgical strategy can be demonstrated clearly. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Fetal aortopulmonary window: case series and review of the literature

Aortopulmonary window is a rare congenital cardiac anomaly characterized by communication between the aorta and the pulmonary artery above the semilunar valves. Prenatal diagnosis is rare. We report four fetuses with aortopulmonary window and review the relevant literature. Approximately half of the reported cases had additional cardiac defects. None had chromosomal abnormalities. In cases with normal cardiac connections, the diagnosis can be made prenatally on the standard three-vessel view, as seen in two of our cases. In one fetus with complete transposition of the great arteries, the diagnosis was made retrospectively on sagittal views. In the remaining case, the window was seen postnatally but could not be identified retrospectively due to the abnormal superoinferior relationship of the ventricles and vessels. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Prevalence of prenatal brain abnormalities in fetuses with congenital heart disease: a systematic review

OBJECTIVES

Studies have shown an association between congenital heart defects (CHDs) and postnatal brain abnormalities and neurodevelopmental delay. Recent evidence suggests that some of these brain abnormalities are present before birth. The primary aim of this study was to perform a systematic review to quantify the prevalence of prenatal brain abnormalities in fetuses with CHDs.

METHODS

MEDLINE, EMBASE and The Cochrane Library were searched electronically. Reference lists within each article were hand-searched for additional reports. The outcomes observed included structural brain abnormalities (on magnetic resonance imaging (MRI)) and changes in brain volume (on MRI, three-dimensional (3D) volumetric MRI, 3D ultrasound and phase-contrast MRI), brain metabolism or maturation (on magnetic resonance spectroscopy and phase-contrast MRI) and brain blood flow (on Doppler ultrasound, phase-contrast MRI and 3D power Doppler ultrasound) in fetuses with CHDs. Cohort and case-control studies were included and cases of chromosomal or genetic abnormalities, case reports and editorials were excluded. Proportion meta-analysis was used for analysis. Between-study heterogeneity was assessed using the I(2) test.

RESULTS

The search yielded 1943 citations, and 20 studies (n = 1175 cases) were included in the review. Three studies reported data on structural brain abnormalities, while data on altered brain volume, metabolism and blood flow were reported in seven, three and 14 studies, respectively. The three studies (221 cases) reporting on structural brain abnormalities were suitable for inclusion in a meta-analysis. The prevalence of prenatal structural brain abnormalities in fetuses with CHD was 28% (95% CI, 18-40%), with a similar prevalence (25% (95% CI, 14-39%)) when tetralogy of Fallot was considered alone. These abnormalities included ventriculomegaly (most common), agenesis of the corpus callosum, ventricular bleeding, increased extra-axial space, vermian hypoplasia, white-matter abnormalities and delayed brain development. Fetuses with CHD were more likely than those without CHD to have reduced brain volume, delay in brain maturation and altered brain circulation, most commonly in the form of reduced middle cerebral artery pulsatility index and cerebroplacental ratio. These changes were usually evident in the third trimester, but some studies reported them from as early as the second trimester.

CONCLUSION

In the absence of known major aneuploidy or genetic syndromes, fetuses with CHD are at increased risk of brain abnormalities, which are discernible prenatally. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Natural history of 107 cases of fetal aortic stenosis from a European multicenter retrospective study

OBJECTIVES

Fetal aortic valvuloplasty (FV) aims to prevent fetal aortic valve stenosis progressing into hypoplastic left heart syndrome (HLHS), which results in postnatal univentricular (UV) circulation. Despite increasing numbers of FVs performed worldwide, the natural history of the disease in fetal life remains poorly defined. The primary aim of this study was to describe the natural history of fetal aortic stenosis, and a secondary aim was to test previously published criteria designed to identify cases of emerging HLHS with the potential for a biventricular (BV) outcome after FV.

METHODS

From a European multicenter retrospective study of 214 fetuses with aortic stenosis (2005-2012), 107 fetuses in ongoing pregnancies that did not undergo FV were included in this study and their natural history was reported. We examined longitudinal changes in Z-scores of aortic and mitral valve and left ventricular dimensions and documented direction of flow across the foramen ovale and aortic arch, and mitral valve inflow pattern and any gestational changes. Data were used to identify fetuses satisfying the Boston criteria for emerging HLHS and estimate the proportion of these that would have been ideal FV candidates. We applied the threshold score whereby a score of 1 was assigned to fetuses for each Z-score meeting the following criteria: left ventricular length and width > 0; mitral valve diameter > -2; aortic valve diameter > -3.5; and pressure gradient across either the mitral or aortic valve > 20 mmHg. We compared the predicted circulation with known survival and final postnatal circulation (BV, UV or conversion from BV to UV).

RESULTS

Among the 107 ongoing pregnancies there were eight spontaneous fetal deaths and 99 livebirths. Five were lost to follow-up, five had comfort care and four had mild aortic stenosis not requiring intervention. There was intention-to-treat in these 85 newborns but five died prior to surgery, before circulation could be determined, and thus 80 underwent postnatal procedures with 44 BV, 29 UV and seven BV-to-UV circulatory outcomes. Of newborns with intention-to-treat, 69/85 (81%) survived ≥ 30 days. Survival at median 6 years was superior in cases with BV circulation (P = 0.041). Those with a postnatal UV circulation showed a trend towards smaller aortic valve diameters at first scan than did the BV cohort (P = 0.076), but aortic valve growth velocities were similar in both cohorts to term. In contrast, the mitral valve diameter was significantly smaller at first scan in those with postnatal UV outcomes (P = 0.004) and its growth velocity (P = 0.008), in common with the left ventricular inlet length (P = 0.004) and width (P = 0.002), were reduced significantly by term in fetuses with UV compared with BV outcome. Fetal data, recorded before 30 completed gestational weeks, from 70 treated neonates were evaluated to identify emerging HLHS. Forty-four had moderate or severe left ventricular depression and 38 of these had retrograde flow in the aortic arch and two had left-to-right flow at atrial level and reversed a-waves in the pulmonary veins. Thus 40 neonates met the criteria for emerging HLHS and BV circulation was documented in 13 (33%). Of these 40 cases, 12 (30%) had a threshold score of 4 or 5, of which five (42%) had BV circulation without fetal intervention.

CONCLUSIONS

The natural history in our cohort of fetuses with aortic stenosis and known outcomes shows that a substantial proportion of fetuses meeting the criteria for emerging HLHS, with or without favorable selection criteria for FV, had a sustained BV circulation without fetal intervention. This indicates that further work is needed to refine the selection criteria to offer appropriate therapy to fetuses with aortic stenosis. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Fetuses with right aortic arch: a multicenter cohort study and meta-analysis

OBJECTIVES

Use of recent antenatal screening guidelines for cardiac abnormalities has increased fetal diagnoses of right aortic arch (RAA). We aimed to establish the outcome of fetal RAA without intracardiac abnormalities (ICA) to guide postnatal management.

METHODS

In the retrospective cohort part of our study, outcome measures were rates of chromosomal abnormalities, 22q11.2 deletion, fetal extracardiac abnormalities (ECA), postnatal ICA and ECA, and symptoms of and surgery for vascular ring. A systematic review and meta-analysis was also performed; results are reported as proportions. Kaplan-Meier analysis of vascular ring cases with surgery as endpoint was performed.

RESULTS

Our cohort included 86 cases; 41 had a vascular ring. Rates of chromosomal abnormalities, 22q11.2 deletion and fetal ECA were 14.1%, 6.4% and 17.4%, respectively. Sixteen studies including our cohort (312 fetuses) were included in the systematic review. Overall rates of chromosomal abnormalities and 22q11.2 deletion were 9.0% (95% CI, 6.0-12.5%) and 6.1% (95% CI, 3.6-9.3%), whilst the respective rates for cases with no ECA were 4.6% (95% CI, 2.3-7.8%) and 5.1% (95% CI, 2.4-8.6%). ECA were seen in 14.6% (95% CI, 10.6-19.0%) prenatally and in 4.0% (95% CI, 1.5-7.6%) after birth. Postnatal ICA were identified in 5.0% (95% CI, 2.7-7.9%). Rate of symptoms of vascular rings (follow-up ≥ 24 months postpartum) was 25.2% (95% CI, 16.6-35.0%), and 17.1% (95% CI, 9.9-25.7%) had surgery. Two-year freedom from surgery was 83.0% (95% CI, 74.3-90.1%).

CONCLUSIONS

Fetal RAA without ICA is more frequently associated with ECA than with chromosomal abnormalities. Most cases, however, are isolated. Vascular-ring symptoms occur in about 25% of cases. Postnatal surveillance is required mainly in the first 2 years after delivery.

Brain abnormalities and neurodevelopmental delay in congenital heart disease: systematic review and meta-analysis

OBJECTIVES

Studies have demonstrated an association between congenital heart disease (CHD) and neurodevelopmental delay. Neuroimaging studies have also demonstrated a high incidence of preoperative brain abnormalities. The aim of this study was to perform a systematic review to quantify the non-surgical risk of brain abnormalities and of neurodevelopmental delay in infants with CHD.

METHODS

MEDLINE, EMBASE and The Cochrane Library were searched electronically without language restrictions, utilizing combinations of the terms congenital heart, cardiac, neurologic, neurodevelopment, magnetic resonance imaging, ultrasound, neuroimaging, autopsy, preoperative and outcome. Reference lists of relevant articles and reviews were hand-searched for additional reports. Cohort and case-control studies were included. Studies reporting neurodevelopmental outcomes and/or brain lesions on neuroimaging in infants with CHD before heart surgery were included. Cases of chromosomal or genetic abnormalities, case reports and editorials were excluded. Between-study heterogeneity was assessed using the I(2) test.

RESULTS

The search yielded 9129 citations. Full text was retrieved for 119 and the following were included in the review: 13 studies (n = 425 cases) reporting on brain abnormalities either preoperatively or in those who did not undergo congenital cardiac surgery and nine (n = 512 cases) reporting preoperative data on neurodevelopmental assessment. The prevalence of brain lesions on neuroimaging was 34% (95% CI, 24-46; I(2) = 0%) in transposition of the great arteries, 49% (95% CI, 25-72; I(2) = 65%) in left-sided heart lesions and 46% (95% CI, 40-52; I(2) =18.1%) in mixed/unspecified cardiac lesions, while the prevalence of neurodevelopmental delay was 42% (95% CI, 34-51; I(2) = 68.9).

CONCLUSIONS

In the absence of chromosomal or genetic abnormalities, infants with CHD are at increased risk of brain lesions as revealed by neuroimaging and of neurodevelopmental delay. These findings are independent of the surgical risk, but it is unclear whether the time of onset is fetal or postnatal.

Total anomalous pulmonary venous connection: impact of prenatal diagnosis

OBJECTIVES

To investigate whether prenatal screening is effective in the detection of total anomalous pulmonary venous connection (TAPVC) and to identify common prenatal features.

METHODS

This was a retrospective collaborative study involving 19 pediatric cardiac centers in the UK, Ireland and Sweden. Cases with TAPVC born between January 1, 1998 and December 31, 2004, and prenatally diagnosed cases whose estimated dates of delivery were within this time frame, were identified. Cases with functionally univentricular circulation or atrial isomerism were excluded. All available data and stored images were reviewed.

RESULTS

Four-hundred and twenty-four cases with TAPVC were identified prenatally or postnatally, of whom eight (1.9%) had a prenatal diagnosis of TAPVC. Median gestational age at fetal diagnosis was 26 + 6 (range, 22 + 4 to 32 + 0) weeks. Six further fetuses with TAPVC had an abnormality diagnosed on prenatal ultrasound, but not the TAPVC. This included other congenital heart defects (four cases) and isolated pleural effusion (two cases). Seventeen (4.0%) of the 422 liveborn infants had a first-degree relative with congenital heart disease; and six of 17 had a sibling with TAPVC. Two died in utero. Of the liveborn infants diagnosed prenatally with TAPVC, none required urgent intervention for pulmonary venous obstruction and all were alive and well at a median of 2.3 (range, 1.0-7.0) years after surgical repair.

CONCLUSION

Prenatal diagnosis of TAPVC is infrequent using current screening methods. Where there is a family history of TAPVC, specialized fetal echocardiography at 20 and 28 weeks' gestation may be indicated.

Single umbilical artery and congenital heart disease in selected and unselected populations

OBJECTIVE

A variable association between single umbilical artery (SUA) and congenital heart disease (CHD) has been reported previously. Discrepancies in the results may be related to the populations studied. In this study we assessed the relationship between SUA and CHD in two well-defined selected and unselected populations.

METHODS

This was a retrospective review of all cases of SUA detected antenatally in a tertiary referral center between 1997 and 2003. Umbilical arteries were routinely identified around the fetal bladder by color-flow Doppler ultrasonography. The unselected population included pregnancies from a well-defined geographical area, delivering in the same hospital. The selected group was referred from other hospitals because of suspected abnormalities or other risk factors. Major CHD was defined as CHD needing postnatal treatment or long-term follow-up.

RESULTS

There were 10 fetuses with major CHD in the selected group: four cases among 25 with extracardiac defects (16%; 95% CI, 4.5-36.1%) and six cases out of 22 with no other abnormalities (27%; 95% CI, 10.7-50.2%; P = 0.35). In the unselected group there were two cases of major CHD, both among the 13 fetuses with extracardiac abnormalities (15%; 95% CI, 2-45%), while there were no major cardiac defects in the 85 fetuses with SUA and no extracardiac abnormalities (0%; 95% CI, 0-4%; P = 0.03).

CONCLUSIONS

The association between SUA and CHD varies dramatically with population selection criteria. The risk for CHD after the detection of SUA in an otherwise apparently normal fetus from an unselected population seems small and may not warrant specialist fetal echocardiography.

Prenatal findings and differential diagnosis of scimitar syndrome and pulmonary sequestration

OBJECTIVES

Scimitar syndrome and pulmonary sequestration (PS) have overlapping features. This accounts for postnatal descriptions of a 'sequestrated lung' in scimitar-syndrome patients. We review the similarities and differences in these two conditions, and the antenatal ultrasound findings that allow correct prenatal identification and differential diagnosis.

METHODS

This was a retrospective analysis of prenatally diagnosed cases of scimitar syndrome or PS that underwent fetal echocardiography between January 1995 and November 2004.

RESULTS

There were five cases of PS and six of scimitar syndrome. Right-sided mediastinal shift (ipsilateral relative to the affected lung) was the commonest indication for referral in scimitar syndrome whereas in sequestration, referral was because of hyperechogenic lung and contralateral mediastinal shift. Lung echogenicity was normal in scimitar syndrome but focally increased in PS. Abnormal, unobstructed pulmonary venous drainage was identified prenatally in four cases of scimitar syndrome. It was normal in three fetuses with sequestration but abnormal and obstructed in the other two cases complicated by hydrothorax. Abnormal systemic arterial supply to the affected lung was easily demonstrated in all fetuses with PS, but could not be shown prenatally in scimitar-syndrome fetuses. Postnatal embolization was warranted in one case with PS and four with scimitar syndrome, one each in the neonatal period.

CONCLUSION

Prenatally, scimitar syndrome and PS are clearly distinct entities based on lung echogenicity and laterality of mediastinal shift. Hyperechogenic lung and dextrocardia indicate the possibility of PS and scimitar syndrome, respectively. Complete delineation of the vascular pattern should be attempted in all, but is more challenging in scimitar syndrome. Obstructed venous return in PS may identify fetuses at risk of developing hydrothorax.

Impact of audit of routine second-trimester cardiac images using a novel image-scoring method

OBJECTIVE

To assess the impact of using an objective scoring method to audit cardiac images obtained as part of the routine 21-23-week anomaly scan.

METHODS

A prospective audit and re-audit (6 months later) were conducted on cardiac images obtained by sonographers during the routine anomaly scan. A new image-scoring method was devised based on expected features in the four-chamber and outflow tract views. For each patient, scores were awarded for documentation and quality of individual views. These were called 'Documentation Scores' and 'View Scores' and were added to give a 'Patient Score' which represented the quality of screening provided by the sonographer for that particular patient (maximum score, 15). In order to assess the overall performance of sonographers, an 'Audit Score' was calculated for each by averaging his or her Patient Scores. In addition, to assess each sonographer's performance in relation to particular aspects of the various views, each was given their own 'Sonographer View Scores', derived from image documentation and details of four-chamber view (magnification, valve offset and septum) and left and right outflow tract views. All images were scored by two reviewers, jointly in the primary audit and independently in the re-audit. The scores from primary and re-audit were compared to assess the impact of feedback from the primary audit.

RESULTS

Eight sonographers participated in the study. The median Audit Score increased significantly (P < 0.01), from 10.8 (range, 9.8-12.4) in the primary audit to 12.4 (range, 10.4-13.6) in the re-audit. Scores allocated by the two reviewers in the re-audit were not significantly different (P = 0.08).

CONCLUSION

Objective scoring of fetal heart images is feasible and has a positive impact on the quality of cardiac images acquired at the time of the routine anomaly scan. This audit tool has the potential to be applied in every obstetric scanning unit and may improve the effectiveness of screening for congenital heart defects.

Criss-cross heart: report of three cases with double-inlet ventricles diagnosed in utero

Criss-cross heart is a rare congenital cardiac anomaly characterized by crossing of the inflow streams of the two ventricles, due to an apparent twisting of the heart about its long axis and when the axes of the openings of the atrioventricular (AV) valves are not parallel. If unrecognized, this leads to incorrect sequential segmental analysis. We report three cases of double-inlet ventricle with a criss-cross spatial relationship of the AV valves detected on prenatal ultrasound examination at 19-23 weeks' gestation. The sequential diagnosis was confirmed at postmortem examination in two cases and by neonatal echocardiography in the other. Antenatal diagnosis of criss-cross effect of the AV valves is feasible, allowing correct fetal diagnosis and appropriate counseling for this rare form of congenital cardiac disease.

Assessment of the intraobserver variability in the measurement of fetal cardiothoracic ratio using ellipse and diameter methods

OBJECTIVE

To assess the variability of fetal heart and thoracic area and circumference measurements using the ellipse and diameter methods at different gestational ages.

DESIGN

This was a prospective cross-sectional study of 200 singleton pregnancies, with no apparent fetal abnormalities. The gestational age ranged between 19 and 42 weeks. At each examination, two transverse frames of the fetal chest at the level of the four-chamber view during diastole were obtained. For each frame, the area and the circumference of the heart and thorax were obtained by the ellipse and diameter methods. In the diameter method, cardiac and thoracic areas and circumferences were derived from the measured anteroposterior and transverse diameters. All measurements were made by the same observer.

RESULTS

For the same method, intraobserver variability was good. Coefficient of variation for all measurements varied between 3-11%. The ellipse method tended to give larger measurements than did the diameter method, the absolute difference increasing with fetal age. The mean ellipse/diameter ratio was 1.10, 1.04, 1.05 and 1.02 for heart area, thorax area, heart circumference and thorax circumference, respectively. In most cases, intraobserver variability of the thorax measurements was independent of gestational age. In contrast, there was a greater variability of heart measurements with increasing gestational age.

CONCLUSIONS

Both the ellipse and diameter methods of measuring cardiothoracic ratio are clinically useful and fairly reproducible at certain gestations, but are not interchangeable as the ellipse method overestimates measurements compared to the diameter method. The less reproducible measurement of heart size in later gestation should be taken into account when assessing cardiothoracic ratios.

Development of Z-scores for fetal cardiac dimensions from echocardiography

OBJECTIVES

Z-scores for cardiac dimensions are well established in postnatal life, but have yet to be developed for fetal cardiac dimensions. These would be of real advantage to the clinician in accurately quantifying size and growth of cardiac dimensions and to the researcher by allowing mathematical comparison of growth in differing subgroups of a disease. The purpose of this observational study, conducted at tertiary fetal medicine and cardiology units, was to produce formulae and nomograms allowing computation of Z-scores for fetal cardiac dimensions from knowledge of femur length (FL), biparietal diameter (BPD) or gestational age (GA) using fetal echocardiography.

METHODS

Seventeen fetal cardiac dimensions were measured in 130 pregnant women with singleton fetuses of gestational age 15-39 weeks. Regression equations were derived relating all dimensions to FL, BPD and GA. From the calculations, formulae were then developed allowing fetal cardiac Z-score computation.

RESULTS

The relationships between cardiac dimensions and FL, BPD or GA were described following natural log transformation. From this analysis, FL (taken as an expression of fetal size) had the highest correlation to fetal cardiac dimensions. From the developed nomograms, Z-scores of specific fetal cardiac structures could be estimated from knowledge of the FL, BPD or GA and echocardiographically derived measurements.

CONCLUSIONS

This study allowed computation of Z-scores in fetal life for 17 cardiac dimensions from FL, BPD or GA. Previous studies of normal data allowed qualitative assessment of where abnormal cardiac dimensions lay with regard to the normal range. Z-scores from this study allow quantitative analysis of where such dimensions lie relative to the mean. This permits exact assessment of growth of fetal cardiac structures in normal hearts and particularly in congenitally abnormal hearts where quantitative assessment of the growth of cardiac structures is important in analyzing and planning treatment strategies.

Increased first-trimester fetal nuchal translucency thickness in association with chondroectodermal dysplasia (Ellis-Van Creveld syndrome)

Increased nuchal translucency thickness (NT) is an established sonographic marker of fetal chromosomal abnormality. Several structural fetal defects and genetic syndromes including a range of skeletal dysplasias have been reported in association with increased NT. We report the first case of fetal Ellis-Van Creveld syndrome presenting as raised fetal NT at 13 weeks' gestation. Ultrasonography at 18 weeks' gestation demonstrated a narrow thorax, marked shortening of the long bones with bowed femora and hexadactyly of hands and feet. Pregnancy was terminated at 23 weeks' gestation. The postmortem radiological examination revealed short and bowed long bones with rounded metaphyses, postaxial polydactyly of hands and feet, short ribs and narrow thorax. The acetabular roofs were horizontal with medial and lateral spurs. This case adds a further type of severe skeletal dysplasia to the list of genetic syndromes which may present as increased fetal NT in the late first trimester.

Fetal congenital cardiac diverticulum with pericardial effusion: two cases with different presentations in the first trimester of pregnancy

Two cases of fetal congenital cardiac diverticula diagnosed at 14 and 12 weeks of gestation are reported. Both presented with a large pericardial effusion. One fetus presented with increased NT which evolved into fetal hydrops. Pericardiocentesis at 16 weeks led to progressive resolution of hydrops. The other showed no hemodynamic compromise, normal nuchal translucency (NT) and spontaneous regression of the effusion. Both children were well at 22 and 17 months of age at the time of writing.

Fetal echocardiography. A sophisticated tool in obstetrics

Fetal cardiology has been evolving as an exciting speciality over the last 20 years or so. Whilst much is due to technical advances in fetal echocardiographic techniques and the use of sophisticated ultrasound equipment, the partnership among fetal and paediatric cardiologists and a team of professionals working in Fetal Medicine Unit should not be ignored. As a result, targeted fetal echocardiography allows congenital heart disease to be diagnosed in utero with a great degree of accuracy from as early as the end of the first trimester of pregnancy i.e. from around 12 weeks. Conversely, prenatal detection rates in the general population remain suboptimal with many congenital cardiac abnormalities being diagnosed postnatally. A recognised marker for chromosomal abnormalities, that is the finding of an increased nuchal translucency thickness at 11-14 weeks of gestation has also emerged over the last few years as a novel and important marker for major cardiac abnormalities. This has further increased the interest in imaging the fetal heart early in the pregnancy.

Clinical impact of first and early second trimester fetal echocardiography on high risk pregnancies

OBJECTIVE

To evaluate the clinical impact of fetal echocardiography before 16 weeks' gestation on the management of pregnancies with fetuses at risk of congenital heart disease.

DESIGN AND SETTING

Observational study in a fetal medicine unit.

PARTICIPANTS AND METHODS

222 consecutive women with high risk pregnancies (230 fetuses) underwent transabdominal fetal echocardiography at a median gestation of 14(+1) weeks. For 10%, transvaginal scans were also performed. Criteria for normal scans were normal sequential segmental analysis, symmetrical four chamber view, normal semilunar valves, arterial outflow tracts, and ductal and aortic arches. Early scans were compared with mid-second trimester fetal echocardiography. Postmortem and postnatal data were added. Adverse pregnancy outcomes were diagnosis of a major cardiac or extracardiac abnormality, chromosomal defects, intrauterine death, or termination of pregnancy.

RESULTS

There were 21 abnormal cardiac scans (9%): 14 major structural defects (eight isolated, six with chromosomal or extracardiac abnormalities) in pregnancies resulting in three live births, one intrauterine death, and 10 terminated pregnancies. Seven scans showed asymmetry between right and left sided structures (two isolated, five with chromosomal or extracardiac abnormalities); six of the seven pregnancies were terminated. The scans were normal in 199 cases (87%). Cardiac follow up of 184 of 199 babies (93%) confirmed situs and connections. One case each of pulmonary stenosis and ventricular septal defect requiring postnatal intervention were diagnosed at later scans. In 28 of 199 (14%) babies there was a non-cardiac adverse outcome. First examination was not diagnostic for 10 (4%).

CONCLUSION

Early fetal echocardiography in high risk pregnancies was diagnostic in 96%. Abnormal cardiac scans (isolated in 48%, major structural defects in 67%) led to termination of pregnancy in 76%. Most cardiac scans were normal, allowing family reassurance. The high number of adverse outcomes with normal cardiac anatomy stresses the need for a multidisciplinary approach to early fetal echocardiography.

Improving the effectiveness of routine prenatal screening for major congenital heart defects

OBJECTIVE

To evaluate the effectiveness of adding outlet views to the four chamber view in routine prenatal ultrasound screening for major congenital heart defects (CHD) as performed by trained sonographers, and to compare the procedure with current practice.

DESIGN AND SETTING

Prospective observational study at a London teaching hospital.

PARTICIPANTS AND METHODS

9277 women booked at a single institution (80% had first trimester nuchal translucency measurement) due to have routine fetal cardiac screening using the four chamber and outflow tract views at > 18 weeks of gestation.

MAIN OUTCOME MEASURE

Identification of major CHD in chromosomally normal and abnormal pregnancies antenatally or postnatally.

RESULTS

There were 40 abnormalities (4.3/1000), of which 30 were chromosomally normal (3.3/1000). The overall antenatal detection rate was 75% (95% confidence interval (CI) 59% to 87%) and 70% (95% CI 51% to 85%) for euploid pregnancies. Abnormal cardiac views accounted for 70% of all prenatal diagnoses, 30% of which were made at < or = 18 weeks. The sensitivity of cardiac views during the first scan at > 18 weeks was 52%. Of all patients undergoing nuchal translucency screening, 34 had major CHD, nine with increased nuchal translucency (26.5%). Factors influencing the results of this screening programme were training and audit of operators, adequate equipment for antenatal examination, ease of access, and low threshold for referral to specialised fetal echocardiography.

CONCLUSION

Adding ventricular outlet views to the four chamber assessment of the heart at routine fetal anomaly scans at > 18 weeks is the most effective technique to detect CHD prenatally. The success of such a programme depends on an infrastructure committed to continuous in house training of obstetric ultrasonographers coupled with feedback from specialised fetal cardiologists, as well as adequate resource allocation to obstetric hospitals involved with antenatal screening.

The human ductus venosus between 13 and 17 weeks of gestation: histological and morphometric studies

BACKGROUND

Doppler studies of the ductus venosus are increasingly being integrated in the assessment of fetal well-being. Establishing the precise morphology and structure of the ductus venosus would provide a better understanding of Doppler findings during fetal adaptation. There is conflicting evidence from previous studies about the structure of the ductus venosus, especially with regard to the presence of a sphincter at the ductus venosus inlet. The aim of this study was to examine the morphology and histological structure of the ductus venosus wall and surrounding tissues at 13-17 weeks' gestation.

DESIGN

This was a prospective study on 28 fetuses obtained from medical termination of pregnancies between 13 and 17 weeks' gestation. Scanning electron microscopy and histological and immunohistochemical studies were carried out on ductus venosus sections obtained from different spatial planes.

RESULTS

The inlet of the ductus venosus contained a shelf which was rich in elastin, but devoid of any evidence of a smooth muscle sphincter. The isthmus of the ductus venosus above the inlet was narrowed, giving the lumen of the vessel an hourglass appearance. The endothelial surface of the ductus venosus, above the level of the inlet, showed longitudinal corrugations along its entire length. Longitudinally arranged elastin fibers were also seen along the length of the ductus venosus. A single layer of longitudinally arranged smooth muscle cells was present along the entire length of the ductus venosus, with occasional individual nerve cells visible in this layer.

CONCLUSIONS

The presence of an elastin-rich shelf and a narrow ductus venosus inlet orifice may act to accelerate flow from the portal sinus into a high-velocity system in the ductus venosus. The abundant elastin fibers in the adventitia of the ductus venosus may help antegrade wave propagation by elastic recoil. This study clearly demonstrates the lack of an anatomical smooth muscle sphincter at the ductus venosus inlet. However, the combination of endothelial corrugations and innervated smooth muscle support the hypothesis that the ductus venosus is an actively regulated vessel with the capacity to rapidly change diameter along its entire length in response to certain stimuli.

The anatomy of the umbilical, portal and hepatic venous systems in the human fetus at 14-19 weeks of gestation

BACKGROUND

Ultrasound imaging of the fetal ductus venosus is becoming increasingly commonplace in clinical practice. The true anatomical relationships of the fetal umbilical and portal venous systems have not been clearly defined due to paucity of published data on the relevant anatomy. This has led to confusing terminology when describing the fetal umbilical, portal and hepatic circulations. The aim of the present study was to examine and document the anatomy of the umbilical, portal and hepatic venous systems and to propose a standardized nomenclature.

METHODS

This was a prospective study on 11 fetuses obtained from medical termination of pregnancies between 14 and 19 weeks of gestation. The liver was microdissected to expose the branching pattern and anatomical relations of the umbilical, portal and hepatic venous systems.

RESULTS

A wide L-shaped venous confluence at the terminal end of the umbilical vein, termed the portal sinus, was identified. The portal sinus was connected to the right and left hepatic lobes, by the right and left intrahepatic portal veins, respectively. The extrahepatic portal vein drained into the portal sinus just before the origin of the right intrahepatic portal vein. The ductus venosus, a branchless straight vessel, originated from the portal sinus and ascended steeply in the direction of the diaphragm. Numerous small vessels draining the liver converged into three main hepatic veins, which open into the subdiaphragmatic vestibulum.

CONCLUSION

Based on detailed sequential anatomical dissection and clear illustrations, the present study documents the anatomy of the umbilical, portal and hepatic venous systems. Taking into account the embryological origin of the vessels, a new anatomically appropriate and simplified nomenclature of these venous systems is proposed. In clinical practice, the consistent use of the suggested terminology would allow collection of comparable data between units and enable operators to be confident of which vessels they are sampling by Doppler ultrasound.

Right and left ventricular long-axis function in the fetus using angular M-mode

OBJECTIVE

Long-axis function is determined by the longitudinally oriented myocardial fibers. Postnatally, conventional M-mode is used to assess tricuspid and mitral valve ring movements in relation to the cardiac apex. During fetal life, this is precluded by variable fetal position. We assessed the feasibility of determining right and left ventricular long-axis function in the fetus.

METHODS

A prospective, pilot study. The four-chamber view obtained during routine fetal echocardiography was recorded in a cineloop to which B-mode guided M-mode echocardiography was applied using angular M-mode. This allowed retrospective and correct placement of the cursor line from cardiac apex to tricuspid or mitral valve rings. M-mode tracings of the valve ring movements in relation to the apex were derived from the originally stored loop. Data from 18 fetuses (17-29 weeks of gestation) were available for analysis. Total excursion of the valve rings was measured offline. A second cursor line was simultaneously placed in the left ventricular outflow tract during color flow mapping for timing purposes (n = 6).

RESULTS

Right and left ventricular long-axis recordings were obtained in 18 and 14 cases, respectively. Total right ventricular excursion was 5.2 mm (SD, 0.9 mm) (range, 3.9-7.2 mm). Total left ventricular free wall excursion was 4.5 mm (SD, 1.1 mm) (range, 3.0-6.8 mm). For paired data, the mean of differences (right ventricle-left ventricle) was 0.8 mm (95% confidence interval 0.5-1.2). The valve rings moved towards the apex during systole (shortening) and away from it during diastole (lengthening). Peak downward movement coincided with cessation of aortic flow and diastolic lengthening with flow through the atrioventricular valves.

CONCLUSION

Long-axis function in the fetus is feasible if M-mode angle correction is used. There was no clinically significant difference between tricuspid and mitral valve excursions. The pattern of atrioventricular valve movement is coordinate and similar to that of adults. Long-axis function offers a new avenue to study systolic and diastolic function in the fetus.

Isolated echogenic foci in the fetal heart: do they increase the risk of trisomy 21 in a population previously screened by nuchal translucency?

OBJECTIVES

To confirm the hypothesis that isolated cardiac echogenic foci at the second-trimester anomaly scan do not influence our current calculation of risk of trisomy 21 in individual pregnancies, which is based on maternal age and nuchal translucency thickness at 11-14 weeks.

DESIGN

Observational study in a fetal medicine unit.

METHODS

In a general pregnant population undergoing first-trimester nuchal translucency screening, data from 239 singleton pregnancies with isolated cardiac echogenic foci at the second-trimester anomaly scan were compared with those of a control group of 7449 pregnancies with normal anomaly scans. Prevalence of trisomy 21 was determined in both groups. Following the anomaly scan, the individual risks of trisomy 21 were calculated by adjusting the previous risk based on maternal age and first-trimester nuchal translucency. We assumed that echogenic foci did not alter each individual risk calculation. The expected number of cases of Down syndrome in both groups was then calculated from the sum of probabilities of each individual affected fetus. The observed number of cases was compared with the expected number in both study and control populations.

RESULTS

There was no statistically significant difference between the prevalence of trisomy 21 in the study group (no cases) and in the control population (three cases). From individual risk calculations, observing no cases of trisomy 21 in the study group was the most likely event if echogenic foci did not increase the risk of this chromosomal abnormality (P = 0.62).

CONCLUSION

The finding of isolated echogenic foci at the time of the 20 week-scan does not significantly change the risks of trisomy 21 if background risk and previous nuchal translucency measurements are taken into account in the individual risk calculation. We suggest that no further adjustments to risk should be used.