Fetal NT-proBNP levels and their course in severe anemia during intrauterine treatment

PURPOSE

In adults and fetuses, N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a marker of cardiac failure and myocardial remodelling. We examined the effect of anemia and intrauterine transfusion (IUT) on NT-proBNP concentrations in fetuses with anemia and established gestational age-dependent reference values of a control group.

METHODS

We analyzed NT-proBNP levels in anemic fetuses that underwent serial intrauterine transfusions (IUT), focusing on different causes and severity of anemia and comparing the results to a non-anemic control group.

RESULTS

In the control group, the average NT-proBNP concentration was 1339 ± 639 pg/ml, decreasing significantly with increasing gestational age (R = - 74.04, T = - 3.65, p = 0.001). Subjects had significantly higher NT-proBNP concentrations before initiation of IUT therapy (p < 0.001), showing fetuses with parvovirus B19 (PVB19) infection having the highest concentrations. Hydropic fetuses also showed an increased NT-proBNP concentration compared to non-hydropic fetuses (p < 0.001). During the course of therapy, NT-proBNP concentration before subsequent IUT decreased significantly from pathologically high levels, while MoM-Hb and MoM-MCA-PSV remained pathological.

CONCLUSION

NT-pro BNP levels in non-anemic fetuses are higher than in postnatal life, decreasing with ongoing pregnancy. Anemia is a hyperdynamic state and its severity correlates with circulating NT-proBNP levels. Highest concentrations occur in fetuses with hydrops and with PVB19 infection, respectively. Treatment by IUT leads to a normalisation of NT-proBNP concentrations, so the measurement of its levels may be useful in therapy monitoring.

Myocardial strain assessment in the human fetus by cardiac MRI using Doppler ultrasound gating and feature tracking

OBJECTIVES

Assessment of myocardial strain by feature tracking magnetic resonance imaging (FT-MRI) in human fetuses with and without congenital heart disease (CHD) using cardiac Doppler ultrasound (DUS) gating.

METHODS

A total of 43 human fetuses (gestational age 28-41 weeks) underwent dynamic cardiac MRI at 3 T. Cine balanced steady-state free-precession imaging was performed using fetal cardiac DUS gating. FT-MRI was analyzed using dedicated post-processing software. Endo- and epicardial contours were manually delineated from fetal cardiac 4-chamber views, followed by automated propagation to calculate global longitudinal strain (GLS) of the left (LV) and right ventricle (RV), LV radial strain, and LV strain rate.

RESULTS

Strain assessment was successful in 38/43 fetuses (88%); 23 of them had postnatally confirmed diagnosis of CHD (e.g., coarctation, transposition of great arteries) and 15 were heart healthy. Five fetuses were excluded due to reduced image quality. In fetuses with CHD compared to healthy controls, median LV GLS (- 13.2% vs. - 18.9%; p < 0.007), RV GLS (- 7.9% vs. - 16.2%; p < 0.006), and LV strain rate (1.4 s-1 vs. 1.6 s-1; p < 0.003) were significantly higher (i.e., less negative). LV radial strain was without a statistically significant difference (20.7% vs. 22.6%; p = 0.1). Bivariate discriminant analysis for LV GLS and RV GLS revealed a sensitivity of 67% and specificity of 93% to differentiate between fetuses with CHD and healthy fetuses.

CONCLUSION

Myocardial strain was successfully assessed in the human fetus, performing dynamic fetal cardiac MRI with DUS gating. Our study indicates that strain parameters may allow for differentiation between fetuses with and without CHD.

CLINICAL RELEVANCE STATEMENT

Myocardial strain analysis by cardiac MRI with Doppler ultrasound gating and feature tracking may provide a new diagnostic approach for evaluation of fetal cardiac function in congenital heart disease.

KEY POINTS

• MRI myocardial strain analysis has not been performed in human fetuses so far. • Myocardial strain was assessed in human fetuses using cardiac MRI with Doppler ultrasound gating. • MRI myocardial strain may provide a new diagnostic approach to evaluate fetal cardiac function.

FHUSP-NET: A Multi-task model for fetal heart ultrasound standard plane recognition and key anatomical structures detection

In prenatal ultrasound screening, rapid and accurate recognition of the fetal heart ultrasound standard planes(FHUSPs) can more objectively predict fetal heart growth. However, the small size and movement of the fetal heart make this process more difficult. Therefore, we design a deep learning-based FHUSP recognition network (FHUSP-NET), which can automatically recognize the five FHUSPs and detect tiny key anatomical structures at the same time. 3360 ultrasound images of five FHUSPs from 1300 mid-pregnancy pregnant women are included in this study. 10 fetal heart key anatomical structures are manually annotated by experts. We apply spatial pyramid pooling with a fully connected spatial pyramid convolution module to capture information about targets and scenes of different sizes as well as improve the perceptual ability and feature representation of the model. Additionally, we adopt the squeeze-and-excitation networks to improve the sensitivity of the model to the channel features. We also introduce a new loss function, the efficient IOU loss, which makes the model effective for optimizing similarity. The results demonstrate the superiority of FHUSP-NET in detecting fetal heart key anatomical structures and recognizing FHUSPs. In the detection task, the value of mAP@0.5, precision, and recall are 0.955, 0.958, and 0.931, respectively, while the accuracy reaches 0.964 in the recognition task. Furthermore, it takes only 13.6 ms to detect and recognize one FHUSP image. This method helps to improve ultrasonographers' quality control of the fetal heart ultrasound standard plane and aids in the identification of fetal heart structures in a less experienced group of physicians.

Hemodynamic changes in late advanced pregnant Zaraibi goats during the peripartum period

The objective of the present study was to demonstrate the blood flow velocities, blood flow rate (BFR; bpm) with the accurate ratio of both systolic and diastolic velocities points (S/D) in addition to Doppler indices (resistive and pulsatility index [RI and PI]) in both fetal [fetal heart (FH), fetal abdominal aorta (Ab. A), and umbilical artery (UM.A)] and maternal [Middle uterine artery (MU.A)] sides during the last month of gestation. Ten Zaraibi (Egyptian Nubian) goats weighing 40-50kg and aged from 5-7 years were examined twice per month till reached the last month of pregnancy. Then all females were examined every 5 days starting from day -35 till day -1 before kidding.The pregnant goats were examined by ultrasonic and Doppler indices were recorded with Doppler scanning (7.5 -12 MHz, with colored and spectral graph to form the perfect wave to assess Doppler measurements). The obtained data were analyzed using analysis of variance. Results indicated that on the fetal side; the maximum point of velocity (MSV; cm/sec) in the FH and BFRwere elevated from day -35 till day -10 with a slight decline at days -5 and -1 at the peripartum period (P < 0.05), while FH.PI and S/D ratio declined till day -1(P < 0.05). In addition, the fetal Ab. A, and UM.A PI, RI, and S/D ratio declined from day -35 till day -1 at the peripartum period with a significant increase in the peak systolic velocity (PSV) and BFR(P < 0.05). However, non-significant changes in the end diastolic velocity (EDV) were detected. On the maternal side, the MU.A PI and S/D declined from day -35 till day -1 with an elevation of both PSV and BFRat the same time points (P < 0.05). In conclusion, the Doppler evaluation of fetal and maternal blood flow vessels is important to give complete information that directly affects the health status of the mother and fetus.

Fetal Pulmonary Venous Return: From Basic Research to the Clinical Value of Doppler Assessment

The fetal pulmonary circulation represents less than 25% of the fetal cardiac output. In comparison with the pulmonary arteries, studies on pulmonary veins are few and limited, and many questions remain to be answered. The literature reports that pulmonary veins play an important role in regulating vascular flow, forming an active segment of the pulmonary circulation. The development of more sophisticated ultrasonography technology has allowed the investigation of the extraparenchymal pulmonary veins and their waveform. The recognition of the pulmonary vein anatomy in echocardiography is important for the diagnosis of anomalous pulmonary venous connections, with a significant impact on prognosis. On the other hand, the identification of the normal pulmonary vein waveform seems to be a reliable way to study left heart function, with potential applicability in fetal and maternal pathology. Thus, the goal of this narrative review was to provide a clinically oriented perspective of the available literature on this topic.

Effects of Gestational Hypoxia on PGC1α and Mitochondrial Acetylation in Fetal Guinea Pig Hearts

Chronic intrauterine hypoxia is a significant pregnancy complication impacting fetal heart growth, metabolism, and mitochondrial function, contributing to cardiovascular programming of the offspring. PGC1α (peroxisome proliferator-activated receptor γ co-activator 1α) is the master regulator of mitochondrial biogenesis. We investigated the effects of hypoxia on PGC1α expression following exposure at different gestational ages. Time-mated pregnant guinea pigs were exposed to normoxia (NMX, 21% O2) or hypoxia (HPX, 10.5% O2) at either 25-day (early-onset) or 50-day (late-onset) gestation, and all fetuses were extracted at term (term = ~65-day gestation). Expression of nuclear PGC1α, sirtuin 1 (SIRT1), AMP-activated protein kinase (AMPK), and mitochondrial sirtuin 3 (SIRT3) was measured, along with SIRT3 activity and mitochondrial acetylation of heart ventricles of male and female fetuses. Early-onset hypoxia increased (P<0.05) fetal cardiac nuclear PGC1α and had no effect on mitochondrial acetylation of either growth-restricted males or females. Late-onset hypoxia had either no effect or decreased (P<0.05) PCC1α expression in males and females, respectively, but increased (P<0.05) mitochondrial acetylation in both sexes. Hypoxia had variable effects on expression of SIRT1, AMPK, SIRT3, and SIRT3 activity depending on the sex. The capacity of the fetal heart to respond to hypoxia differs depending on the gestational age of exposure and sex of the fetus. Further, the effects of late-onset hypoxia on fetal heart function impose a greater risk to male than female fetuses, which has implications toward cardiovascular programming effects of the offspring.

Fetal heart foramen ovale area by three-dimensional ultrasound using stic in the rendering mode: reference range and applicability in congenital heart diseases

To determine reference values for the foramen ovale (FO) area of fetal hearts by three-dimensional (3D) ultrasound using spatio-temporal image correlation (STIC) method in the rendering mode, as well as applicability in fetuses with congenital heart disease (CHD). A retrospective and prospective study was performed of 242 normal fetuses and 36 fetuses with CHD between 20 and 33 + 6 weeks of gestation. The FO area was determined in the four-chamber view with manual delineation. To determine the reference curve of the FO area as a function of gestational age (GA), a linear regression model was utilized with an adjusted coefficient of determination (R²). For intra- and interobserver reproducibility calculations, the concordance correlation coefficient (CCC) was used. The mean ± standard deviation (SD) of the FO measurement area was 21.2 ± 1.8 and 48.1 ± 1.9 mm² at 20 and 33 weeks' gestation, respectively. A linear correlation was observed between the FO area and GA (1.924*GA - 17.95; R² = 0.91). Good intra- (CCC = 0.97) and interobserver (CCC = 0.94) agreement was observed for the FO area measurement. The mean difference in FO area between normal and CHD fetuses was - 14.4 mm² (p < 0.001). Reference values for the FO area of fetal hearts were determined by 3D ultrasound using STIC in the rendering mode. This method showed good intra- and interobserver reproducibility and could be used to assess different CHD types.

Case report of rare congenital cardiovascular anomalies associated with truncus arteriosus type 2

Truncus arteriosus (TA) is a very rare congenital anomaly with complex cardiovascular anatomy and high lethality also due to severe associated anatomical variants and pathologies. As TA has a massive impact on the survival of a newborn and usually has to be surgically treated. Thus, it is of high importance to understand this congenital cardiovascular disease and associated complications, to improve life expectancy and outcome of these patients. We recently came across a newborn female patient with a rare complex case of persistent TA type 2 associated with further complex cardiovascular anomalies, who received a contrast enhanced CT scan on the 3 rd day post-partum, showing complex cardiovascular abnormalities that were ultimately incompatible with life.

Automated 3D reconstruction of the fetal thorax in the standard atlas space from motion-corrupted MRI stacks for 21-36 weeks GA range

Slice-to-volume registration (SVR) methods allow reconstruction of high-resolution 3D images from multiple motion-corrupted stacks. SVR-based pipelines have been increasingly used for motion correction for T2-weighted structural fetal MRI since they allow more informed and detailed diagnosis of brain and body anomalies including congenital heart defects (Lloyd et al., 2019). Recently, fully automated rigid SVR reconstruction of the fetal brain in the atlas space was achieved in Salehi et al. (2019) that used convolutional neural networks (CNNs) for segmentation and pose estimation. However, these CNN-based methods have not yet been applied to the fetal trunk region. Meanwhile, the existing rigid and deformable SVR (DSVR) solutions (Uus et al., 2020) for the fetal trunk region are limited by the requirement of manual input as well the narrow capture range of the classical gradient descent based registration methods that cannot resolve severe fetal motion frequently occurring at the early gestational age (GA). Furthermore, in our experience, the conventional 2D slice-wise CNN-based brain masking solutions are reportedly prone to errors that require manual corrections when applied on a wide range of acquisition protocols or abnormal cases in clinical setting. In this work, we propose a fully automated pipeline for reconstruction of the fetal thorax region for 21-36 weeks GA range T2-weighted MRI datasets. It includes 3D CNN-based intra-uterine localisation of the fetal trunk and landmark-guided pose estimation steps that allow automated DSVR reconstruction in the standard radiological space irrespective of the fetal trunk position or the regional stack coverage. The additional step for generation of the common template space and rejection of outliers provides the means for automated exclusion of stacks affected by low image quality or extreme motion. The pipeline was quantitatively evaluated on a series of experiments including fetal MRI datasets and simulated rotation motion. Furthermore, we performed a qualitative assessment of the image reconstruction quality in terms of the definition of vascular structures on 100 early (median 23.14 weeks) and late (median 31.79 weeks) GA group MRI datasets covering 21 to 36 weeks GA range.

Fluid Mechanics of Fetal Left Ventricle During Aortic Stenosis with Evolving Hypoplastic Left Heart Syndrome

In cases of fetal aortic stenosis and evolving Hypoplastic Left Heart Syndrome (feHLHS), aortic stenosis is associated with specific abnormalities such as retrograde or bidirectional systolic transverse arch flow. Many cases progressed to hypoplastic left heart syndrome (HLHS) malformation at birth, but fetal aortic valvuloplasty can prevent the progression in many cases. Since both disease and intervention involve drastic changes to the biomechanical environment, in-vivo biomechanics likely play a role in inducing and preventing disease progression. However, the fluid mechanics of feHLHS is not well-characterized. Here, we conduct patient-specific echocardiography-based flow simulations of normal and feHLHS left ventricles (LV), to understand the essential fluid dynamics distinction between the two cohorts. We found high variability across feHLHS cases, but also the following unifying features. Firstly, feHLHS diastole mitral inflow was in the form of a narrowed and fast jet that impinged onto the apical region, rather than a wide and gentle inflow in normal LVs. This was likely due to a malformed mitral valve with impaired opening dynamics. This altered inflow caused elevated vorticity dynamics and wall shear stresses (WSS) and reduced oscillatory shear index at the apical zone rather than mid-ventricle. Secondly, feHLHS LV also featured elevated systolic and diastolic energy losses, intraventricular pressure gradients, and vortex formation numbers, suggesting energy inefficiency of flow and additional burden on the LV. Thirdly, feHLHS LV had poor blood turnover, suggesting a hypoxic environment, which could be associated with endocardial fibroelastosis that is often observed in these patients.

Antenatal diagnosis of congenital heart disease by 3D ultrasonography using spatiotemporal image correlation with HDlive Flow and HDlive Flow silhouette rendering modes

This pictorial review describes the assessment of a great variety of types of congenital heart disease by three-dimensional ultrasonography with spatiotemporal image correlation using HDlive and the HDlive Flow silhouette rendering mode. These technologies provide fetal heart surface patterns by using a fixed virtual light source that propagates into the tissues, permitting a detailed reconstruction of the heart structures. In this scenario, ultrasound operators can freely select a better light source position to enhance the anatomical details of the fetal heart. HDlive and the HDlive Flow silhouette rendering mode improve depth perception and the resolution of anatomic cardiac details and blood vessel walls compared to standard two-dimensional ultrasonography.

Fetal Cardiac Function: Myocardial Performance Index

The Myocardial Performance Index (MPI) or Tei index, presented by Tei in 1995, is the ratio of the sum of the duration of the isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT) to the duration of the ejection time (ET). The Modified Myocardial Performance Index (Mod-MPI), proposed in 2005, is considered a reliable and useful tool in the study of fetal heart function in several conditions, such as growth restriction, twin-twin transfusion syndrome, maternal diabetes, preeclampsia, intrahepatic cholestasis of pregnancy, and adverse perinatal outcomes. Nevertheless, clinical translation is currently limited by poorly standardised methodology as variations in the technique, machine settings, caliper placement, and specific training required can result in significantly different MPI values. This review aims to provide a survey of the relevant literature on MPI, present a strict methodology and technical considerations, and propose future research.

Is Cardiomegaly an Indication of "Heart-Sparing Effect" in Small Fetuses?

INTRODUCTION

This study aimed to test the hypothesis that cardiac size is maintained in small fetuses presenting with cardiomegaly.

MATERIALS AND METHODS

We identified singleton fetuses with estimated fetal weight <10th centile and with cardiomegaly without another more likely cardiac or extra-cardiac cause. We used Z-scores for cardiac and thoracic circumferences normalized for gestational age (GA), biparietal diameter (BPD), head circumference (HC), and femur length (FL), obtained from 188 normally grown fetuses.

RESULTS

When comparing chest size, small fetuses had significantly lower thoracic circumferences median Z-scores (IQR) for GA = -4.82 (-6.15 to -3.51), BPD = -2.42 (-4.04 to -1.48), HC = -2.72 (-4.53 to -1.90), and FL = -1.60 (-2.87 to -0.71); p < 0.001 for all. When comparing heart size, small fetuses showed lower cardiac circumferences median Z-scores (IQR) for GA = -1.59 (-2.79 to -0.16); p < 0.001, similar cardiac circumferences Z-scores for BPD = 0.29 (-0.65 to 1.28); p = 0.284 and HC = 0.11 (-1.13 to 0.96); p = 0.953, and higher cardiac circumferences Z-scores for FL = 0.94 (-0.05 to 2.13); p < 0.001.

CONCLUSIONS

Our results show that in small fetuses with cardiomegaly, the heart maintains normal dimensions when normalized to cranial diameters and higher dimensions when normalized to long bones. This provides insight into cardiac adaptation to adverse intrauterine environment.

Cardiomyopathy and cardiac function in fetuses and newborns of diabetic mothers

OBJECTIVE

To evaluate cardiac function and structural changes in children of diabetic mothers in the fetal and neonatal period using Doppler-echocardiographic data.

METHOD

A prospective, descriptive observational study conducted in a private and tertiary care service for high-risk pregnant women. It included 48 children of mothers with gestational diabetes mellitus (GDM) considered clinically compensated during pregnancy, with a single fetus and absence of malformations. Myocardial thickness, shortening fraction, left ventricular (LVMPI) and right ventricular (RVMPI) myocardial performance index, and mitral and tricuspid valve E/A ratio were evaluated in 96 echocardiographic exams with Doppler.

RESULTS

The hypertrophic cardiomyopathy was 29% vs 6% p = 0.006 in the prenatal and postnatal periods respectively. The shortening fraction was 0% vs 6% p = 0.242 in the fetuses and newborns respectively. The myocardial performance index of the right ventricle was 12% vs 54% p ≤ 0.001, and on the left ventricle 27% vs 60% p = 0.001 in the prenatal and postnatal periods respectively. The ratio of mitral valve E/A waves was 6% vs 50% p ≤ 0.001 and the ratio of tricuspid valve E/A waves was 0% vs 27% p ≤ 0.001 in the fetuses and newborns respectively.

CONCLUSION

A decrease in the rate of myocardial hypertrophy and changes in cardiac function parameters were observed in the fetal and neonatal periods.

Evaluation of the sphericity index of the fetal heart during middle and late pregnancy using fetalHQ

OBJECTIVE

To explore the feasibility of the fetal heart quantitative technique (fetalHQ) for evaluating the sphericity index (SI) of the fetal heart during middle and late pregnancy.

METHODS

Ninety-six normal fetuses in middle and late gestation who underwent systemic ultrasound examination in the Department of Ultrasound of the Maternal and Child Health Care Hospital of Hunan Province in November 2020 were enrolled, and dynamic images of the four-chamber view of the fetal heart were collected. The correlation between the global sphericity index (GSI), ventricular 24-segment SI, and gestational age (GA) was analyzed, and the differences between the left and right ventricular 24-segment SI were compared.

RESULTS

The success rate of fetalHQ analysis was 93.75%. There was no significant linear correlation between GSI and ventricular 24-segment SI and GA (all ps > .05). The differences in SI between segments 1 and 9 and 15 and 24 in the left and right ventricles were statistically significant (all ps < .05), while the differences in SI between segments 10 and 14 were not statistically significant (all ps > .05). In segments 1-9, the SI of the right ventricle was smaller than that of the left ventricle, indicating that the right ventricle was significantly more spherical than the left ventricle. In segments 15-24, the opposite was true.

CONCLUSION

FetalHQ is a simple and reliable method for evaluating the GSI and 24-segment SI of the left and right ventricles. It can provide some theoretical basis for the clinical quantitative evaluation of fetal heart geometry and lay a foundation for the quantitative evaluation of fetal heart function in cases of structural and functional abnormalities.

The presence of cytoplasmic strings in human blastocysts is associated with the probability of clinical pregnancy with fetal heart

PURPOSE

Is the presence of cytoplasmic strings (CS) in human blastocysts associated with the probability of clinical pregnancy with fetal heart (CPFH) after transfer.

METHODS

This case-control study involved 300 single blastocyst transfers. 150 of these resulted in a CPFH (cases) while 150 did not (controls). All embryos were cultured in Embryoscope+ and AI software (IVY) was used to select the blastocyst with the highest score from the cohort for transfer. An embryologist, blind to the transfer outcome, recorded the CS number, location, and duration of their activity.

RESULTS

There was a significant difference in the number of blastocysts that contained CS, with 97.3% of women's blastocysts resulting in +CPFH containing the CS compared to 88.7% of blastocysts in women who did not have a pregnancy (p = 0.007, OR; 4.67, CI 95% 1.5-14.2). CS appeared 2.4 h earlier in embryo development in the +CPFH group compared to their negative counterparts (p = 0.007). There was a significant difference in the average number of CS/blastocyst with a higher number being present in those that achieved a clinical pregnancy (mean: 6.2, SD 2.9) compared to those that did not (mean: 4.6, SD 3.0) (p ≤ 0.0001). There was a significant increase in the number of vesicles seen traveling along the CS with more seen in the blastocysts resulting in a +CPFH (mean: 4.3 SD 2.1) compared to those in the -CPFH group (mean: 3.1, SD 2.1).

CONCLUSION

This study has shown that the presence of cytoplasmic strings in human blastocysts is associated with the probability of clinical pregnancy with fetal heart.

Reference values for left and right ventricular systolic-to-diastolic duration ratio (SDR) found using both spectral and tissue Doppler of fetal heart between 20 and 36+6 weeks of gestation

PURPOSE

To establish reference values for the systolic-to-diastolic duration ratio (SDR) of the left ventricle (LV) using spectral Doppler, as well as for the SDR' of the interventricular septum (SEP), LV, and right ventricles (RV) using tissue Doppler of the fetal heart.

METHOD

This prospective and cross-sectional study evaluated 374 low-risk singleton pregnancies from 20 to 36 + 6 weeks of gestation. The ventricular filling time (FT) was obtained from LV inflow using spectral Doppler. Tissue Doppler was used to assess the FT of each ventricle by placing the cursor at the atrioventricular junction marked by the mitral and tricuspid valves, respectively. SDR was calculated as the sum of the isovolumic contraction time (ICT) and the ejection time (ET) divided by the sum of the isovolumic relaxation time (IRT) and the ventricular FT. We used regression analysis to obtain the best-fit model polynomial equation for the parameters. The concordance correlation coefficient (CCC) was used to assess intra- and inter-observer reproducibility.

RESULTS

SDR and SDR' LV showed a progressive decrease with gestational age (GA); the SDR' RV and SDR' SEP did not show a significant decrease with advancing GA. The SDR LV (r = 0.29, p < 0.0001), SDR' RV (r = 0.21, p < 0.0001), SDR' LV (r = 0.20, p = 0.0001), and SDR' SEP (r = 0.25, p < 0.0001) showed a significant weak positive correlation with fetal heart rate. The inter-observer SDR' SEP measurements demonstrated poor reproducibility (CCC: 0.50), whereas intra-observer SRD LV measurements demonstrated moderate reproducibility (CCC: 0.78).

CONCLUSIONS

Reference values for SDR SEP, LV, and RV using spectral and tissue Doppler of fetal heart were established between 20 and 36+6 weeks of gestation.

Spectral Doppler, tissue Doppler, and speckle-tracking echocardiography for the evaluation of fetal cardiac function: an update

The functional assessment of the fetal heart has been incorporated into cardiac ultrasound screening as a routine procedure, encompassing fetuses with and without structural heart diseases. It has long been known that various cardiac and extracardiac conditions, such as fetal growth restriction, fetal tumors, twin-to-twin transfusion syndrome, fetal anemia, diaphragmatic hernia, arteriovenous fistula with high cardiac output, and congenital heart diseases (valvular regurgitation and primary myocardial disease), can alter hemodynamic status and fetal cardiac function. Several ultrasound and Doppler echocardiographic parameters of fetal cardiovascular disease have been shown to correlate with perinatal mortality. However, it is still difficult to identify the signs of fetal heart failure and to determine their relationship with prognosis. The aim of this study was to review the main two-dimensional Doppler ultrasound parameters that can be used in the evaluation of fetal cardiac function, with a focus on how to perform that evaluation and on its clinical applicability.

Prenatal evaluation of fetal atrioventricular valves by real-time 4D volume imaging with electronic matrix probe

Background

The purpose of this study is to evaluate the feasibility using real-time four-dimensional (RT 4D) volume imaging with electronic matrix probe to observe the morphology of atrioventricular valves in normal and abnormal fetuses, measure the area and circumference of atrioventricular valves in normal fetuses and analyze the correlation with gestational age.

Methods

RT 4D volume imaging with electronic matrix probe was used to collect cardiac volume data of 162 normal fetuses with the gestational age from 22 to 32 weeks and 19 fetuses with atrioventricular valves abnormalities were also enrolled. All the volume data were analyzed and processed in real-time. The morphology of mitral and tricuspid valves was observed in surface mode. The area and circumference of valves were measured in a 4D render view at the end of diastole and analyzed the correlation with gestational age.

Results

In 148 of 162 fetuses (91%), the 4D rendered image could be successfully obtained, which clearly showed the morphology of the atrioventricular valves. The area and circumference of mitral and tricuspid valves were positively correlated with gestational age (P < 0.01). Furthermore, 4D rendered images were successfully obtained in 17 of 19 fetuses (89%) with atrioventricular valves abnormalities.

Conclusions

The reference range of the area and circumference of atrioventricular valves in normal fetuses at different gestational weeks could be determined by using the RT 4D volume imaging with electronic matrix probe, which can provide certain diagnostic information for the clinic. The RT 4D images could display the valves morphology vividly in both normal and abnormal fetuses, including some subtle lesions which are not identified by traditional two-dimensional (2D) echocardiography. It is feasible to use the RT 4D volume imaging with electronic matrix probe to perform the prenatal evaluation in the fetal atrioventricular valves.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12947-021-00240-7.

Fetal cardiac function by mitral and tricuspid annular plane systolic excursion using spatio-temporal image correlation M-mode and left cardiac output in fetuses of pregestational diabetic mothers

Objective

To assess the mitral and tricuspid annular plane systolic excursions (MAPSE and TAPSE, respectively) and cardiac output (CO) in fetuses of pregnant women with pregestational diabetes mellitus (DM) using spatio-temporal image correlation M-mode (STIC-M) and virtual organ computer-aided analysis (VOCAL).

Methods

This study was prospective and cross-sectional. It included 45 fetuses each from mothers with pregestational DM and healthy mothers, with gestation ages ranging from 20 to 36.6 weeks. The fetal cardiac volumes were obtained and analyzed by STIC and VOCAL methods. MAPSE and TAPSE were measured by STIC-M in the apical or basal four-chamber view. The values of the right (RV) and left ventricular (LV) CO were calculated by STIC and VOCAL.

Results

The median values of TAPSE were 6.1 and 6.2 mm in the diabetic and control groups (P<0.001), respectively. The median values of MAPSE were 4.6 mm in the fetuses of mothers with diabetes and 4.8 mm in fetuses of healthy mothers. The fetal LV CO (60.4 L/min vs. 71.1 L/min; P=0.033, respectively) and RV CO (65.2 vs. 70.1 L/min; P=0.026, respectively) were lower in the pregestational DM group than in the control group. A significant effect of pregestational DM was observed in all functional parameters after adjusting, with fetal heart rate as covariant. There was moderate significant positive correlation between MAPSE and LV CO (r=0.53; P=0.0001) and between TAPSE and RV CO (r=0.46; P=0.0001).

Conclusion

Significant difference in functional parameters (TAPSE, MAPSE and LV CO) obtained by STIC and VOCAL were observed in the fetuses of the pregestational DM group compared to those of the control group.

Identification of cell-to-cell interactions by ligand-receptor pairs in human fetal heart

The heart is the first organ to form during embryogenesis and its development is a complex process. In this study, we identified 120 ligand-receptor pairs including 65 ligands and 58 receptors specifically expressed in one of the nine cell types. The correlation analysis of the cell proportions revealed that the cell-to-cell contact exhibited spatial patterns in human fetal heart. Specifically, the cardiomyocytes (CMs) proportion might have negative correlation with proportion of endothelial cell in left atrium and ventricle during the heart development. In contrast, fibroblast-like cells and macrophages were jointly increased with the gestation. Furthermore, the ligand in CM, NPPA (Natriuretic Peptide A), and receptor in endothelial cell (EC), NPR3 (Natriuretic Peptide Receptor 3), were specifically expressed in atrial CM and endocardial cells, respectively, indicating that the atrial CM might communicate with endocardial cells via NPPA-NRP3 interaction. Moreover, the interplay between fibroblast-like cell and macrophage was observed in both left and right atriums via the ligand-receptor interactions of COL1A1/COL1A2 (Collagen Type I Alpha 1/2 Chain)-CD36 and CTGF (connective tissue growth factor)-ITGB2 (Integrin Subunit Beta 2). Functional enrichment analysis revealed that the ligand-receptor interactions might be associated with the intracellular activation of cGMP-PKG signaling pathway in ECs, PDGF-beta signaling pathway in fibroblast-like cell, and Toll-like receptor signaling in macrophage, respectively. Collectively, the present study unveiled the potential cell-cell communication and underlying mechanism involved in cardiac development, which broadened our insights into developmental biology of heart.

Reference ranges of filling time and systolic-to-diastolic time index of the left ventricle, right ventricle, and interventricular septum using both spectral and tissue Doppler of fetal heart between 20 and 36 + 6 weeks of gestation

OBJECTIVE

The objective of this study is to determine the reference ranges for filling time (FT) and systolic-to-diastolic time index (SDI) of the left ventricle (LV) by using spectral Doppler, and FT' and SDI' of the LV, right ventricle, and interventricular septum (IVS) by using tissue Doppler of the fetal heart.

STUDY DESIGN

This prospective and cross-sectional study included 360 low-risk singleton pregnancies between 20 and 36 + 6 weeks of gestation. The SDI/SDI' is the sum of the ejection time, isovolumic contraction time, and isovolumic relaxation time (IRT) divided by the FT. We measured FT/FT' from the beginning of the opening click of the E wave of the mitral valve to the closing click of the A wave of the mitral valve. We used regression analysis to obtain the best-fit model polynomial equation for the parameters. Additionally, we assessed intra- and inter-observer reproducibility by using concordance correlation coefficient (CCC).

RESULTS

There was a weak correlation among FT LV (r = 0.31, p < 0.0001), SDI LV (r = -0.23, p < 0.0001), and gestational age (GA). Additionally, there was a very weak positive correlation among FT' RV (r = 0.09, p = 0.0001), FT' LV (r = 0.07, p < 0.0001), FT' IVS (r = 0,08, p < 0.0001), and GA. In contrast, there was a very weak negative correlation among SDI' LV (r=-0.09, p < 0.0001), SDI' IVS (r=-0.05, p < 0.0021), and GA. There was no significative correlation between SDI' RV (r=-0.06, p < 0.081) and GA. Poor/very poor intra- and inter-observer reliability was observed for all the parameters (CCC = 0.19-0.79), whereas moderate intra- and inter-observer agreement was observed for all parameters (CCC = 0.37-0.72).

CONCLUSIONS

The reference ranges for FT and SDI were determined by using spectral and tissue Doppler of the fetal heart and showed a poor reproducibility.

Fetal strain and strain rate during pregnancy measured with speckle tracking echocardiography: A systematic review

Establishment of the maturational patterns of the fetal left and right ventricle strain and strain rate by two-dimensional speckle tracking echocardiography is a prerequisite for its routine clinical adaptation in pregnancy. The aim of this study is to review systematically current literature on the development of left and right ventricle strain and strain rate derived by speckle tracking during gestation. EMBASE, Medline and Central were searched, from inception to October 2019, for observational studies of singletons in uncomplicated, non-anomalous pregnancies, measuring global longitudinal strain and strain rate with 2D speckle tracking echocardiography in the fetal heart during gestation. 23 Studies met the inclusion criteria. The gestational age of the included fetuses varied from 12 to 42 weeks. Four studies used a longitudinal study design, with few consecutive measurements at varying gestational ages. 19 Studies performed either cross sectional or both longitudinal and cross sectional measurements. The ultrasound devices and speckle tracking algorithm software used, varied. Strain and strain rate during gestation increased, decreased or remained stable in the left and right fetal ventricle with increasing gestation. Due to considerable variation in the included gestational ages measured and inconsistency in the direction of strain and strain rate development, a meta-analysis could not be performed. Contradictory results concerning the development of strain and strain rate during gestation were shown, probably due to suboptimal study designs and varying algorithms and ultrasound devices used. A large longitudinal cohort study is needed to obtain reference values for fetal cardiac deformation in the uncomplicated, singleton pregnancy.

Efficacy of fetal cardiac axis evaluation in the first trimester as a screening tool for congenital heart defect or aneuploidy

Objective

To prove the efficacy of determining the abnormal fetal cardiac axis for screening congenital heart defects (CHDs) and predicting fetal aneuploidy at 11.0 to 13.6 weeks of pregnancy.

Methods

This retrospective study was performed at a single high-risk pregnancy center. The fetal cardiac axis was evaluated between 11.0 and 13.6 weeks of gestation in 142 fetuses. The cardiac axis in a 4-chamber view was measured as the angle between the line tracing the long axis of the heart and the line bisecting the thorax in the anteroposterior direction. A CHD was confirmed based on the second- to third-trimester fetal status or postnatal imaging. Aneuploidy was diagnosed using chorionic villus sampling, amniocentesis, or genetic testing after birth. Fisher's exact test was performed to assess the association between the fetal cardiac axis and the abnormal fetal status. A 2-way contingence table analysis was performed to confirm the efficacy of the fetal cardiac axis as a screening tool.

Results

Among the 142 fetuses, 10 had a CHD while 17 had aneuploidy. The abnormal fetal cardiac axis was significantly associated with CHDs (P=0.013) and aneuploidy (P=0.010). None of the fetuses with CHDs or aneuploidy had an isolated abnormal cardiac axis alone without other sonographic findings. The sensitivity of the fetal cardiac axis was 50.0% for CHDs and 41.2% for aneuploidy.

Conclusion

The fetal cardiac axis can be an additional helpful tool for prenatal screening of CHDs and aneuploidy in the first trimester.

Main Patterns of Fetal Cardiac Remodeling

The heart is a central organ in the fetal adaptation to an adverse environment. Fetal cardiac changes may persist postnatally and increase the risk of cardiovascular disease in adulthood. Knowledge about fetal cardiac structural as well as functional remodeling has radically improved over the last few years. As it occurs in postnatal life, the fetal heart remodels - changing its structure and shape - to adapt to an insult. Several conditions have been reported to be associated with fetal cardiac remodeling including intrauterine growth restriction, diabetes, exposure to antiretroviral drugs, conception by assisted reproductive technologies, pulmonary stenosis, and other congenital heart diseases. Here we summarized the main observable patterns of cardiac remodeling, i.e., globular shape, hypertrophy without dilation, and hypertrophy with cardiomegaly. We discuss the potential pathophysiology behind different types of remodeling. Defining precisely the distinct patterns of fetal cardiac remodeling is critical for advancing in the understanding of fetal cardiovascular programming and its consequences on adult health, and potentially for the design of preventive strategies that might have an impact on long-term cardiovascular health.

The Transitional Heart: From Early Embryonic and Fetal Development to Neonatal Life

Formation of the human heart involves complex biological signals, interactions, specification of myocardial progenitor cells, and heart tube looping. To facilitate survival in the hypoxemic intrauterine environment, the fetus possesses structural, physiological, and functional cardiovascular adaptations that are fundamentally different from the neonate. At birth, upon separation from the placental circulation, the neonatal cardiovascular system takes over responsibility of vital processes for survival. The transition from the fetal to neonatal circulation is considered to be a period of intricate physiological, anatomical, and biochemical changes in the cardiovascular system. With a successful cardiopulmonary transition to the extrauterine environment, the fetal shunts are functionally modified or eliminated, enabling independent life. Investigations using medical imaging tools such as ultrasound and magnetic resonance imaging have helped to define normal and abnormal patterns of cardiac remodeling both in utero and ex utero. This has not only allowed for a better understanding of how congenital cardiac malformations alter the hemodynamic transition to the extrauterine environment but also how other more common complications during pregnancy including intrauterine growth restriction, preeclampsia, and preterm delivery adversely affect offspring cardiac remodeling during this early transitional period. This review article describes key cardiac progenitors involved in embryonic heart development; the cellular, physiological, and anatomical changes during the transition from fetal to neonatal circulation; as well as the unique impact that different pregnancy complications have on cardiac remodeling.

Anatomical structure segmentation from early fetal ultrasound sequences using global pollination CAT swarm optimizer-based Chan-Vese model

The structure of an early fetal heart provides essential information for the diagnosis of fetus defects. Accurate segmentation of anatomical structure is a major challenging task because of the small size, low signal-to-noise ratio, and rapid movement of the ultrasound images. In recent years, active contour methods have found applications to ultrasound image segmentation. The familiar region-based Chan-Vese (RCV) model is a strong and flexible technique that is able to segment many types of images compared to other active contours. However, the solution trapping in local minima is the main drawback determined on the RCV model with the exposure of improper initial contours. Also, the RCV model showed poor results with this situation. More probably, the images having large intensity differences between global and local structures usually suffered from this problem. To solve this issue, we develop an improved version of the RCV model which is expected to achieve satisfactory segmentation performance, irrespective of the initial selection of the contour. We have formulated a new and hybrid meta-heuristic optimization algorithm namely global pollination-based CAT swarm (GPCATS) optimizer to solve the fitting energy minimization problem. In the GPCATS method, the global pollination step of the flower pollination algorithm (FPA) is used for improving the distance averaging of the CATS algorithm. The performance of the proposed method was analyzed on different fetal heart ultrasound videos acquired from 12 subjects. Each frame of each video was manually annotated in order to provide labels for training and validating the model. Experimental results of the proposed model proved that the precision of locating boundaries is improved greatly and requires only a reduced number of iterations (75% less) for convergence compared to the traditional RCV model. This proposed method also proved that our model not only enhances the accuracy of locating boundaries but also works stronger robustness than some other active contour methods. Graphical Abstract Anatomical structure segmentation from early fetal ultrasound sequences using GPCATS based Chan-Vese Model.

Z-Score Reference Ranges for Fetal Heart Functional Measurements in a Large Brazilian Pregnant Women Sample

The objective of this study was to determine the reference values for fetal heart functional measurements at 24 and 34 weeks of gestation and to develop Z-score equations for all measurements. A single-center, prospective, cross-sectional study with normal fetuses between 24 and 34 weeks of gestation was performed. All pregnant women underwent a comprehensive fetal Doppler echocardiogram with anatomical and functional analysis. Measurements of left and right cardiac output, combined cardiac output, mitral and tricuspid valve flow, inferior vena cava flow, and pulmonary vein flow were performed. The Shapiro-Wilk test and histogram evaluation were performed on all variables. Linear regression was used to assess the relationships between measurements and gestational age. A total of 612 pregnant women with singleton and normal fetuses were included. We assessed the reference values and percentiles of cardiac function as a function of gestational age. The variables that were not normally distributed were subjected to logarithmic or square root transformation. Eleven Z-score equations were developed, with equations for left and right ventricle output and combined cardiac output that were dependent on gestational age and with other equations that were independent of gestational age. The present study produced a large database, allowing the demonstration of reference values and percentiles as well as the development of Z-score equations to facilitate the echocardiographic evaluation of fetal heart function.

How to perform a functional assessment of the fetal heart: a pictorial review

The purpose of this pictorial review was to describe various echocardiographic techniques that can be used for the functional assessment of the fetal heart. The systolic and diastolic assessments of the fetal heart are presented separately, with an emphasis on 2-dimensional Doppler methods and an overview of new technologies. The aim of this summary was to review the tools that can be used by the echocardiographer, and on that basis, to systematize the process of performing a functional assessment.

Nomograms of Fetal Cardiac Dimensions at 18-41 Weeks of Gestation

OBJECTIVE

There is a need for standardized reference values for cardiac dimensions in prenatal life. The objective of the present study was to construct nomograms for fetal cardiac dimensions using a well-defined echocardiographic methodology in a low-risk population.

METHODS

This is a prospective cohort study including 602 low-risk singleton pregnancies undergoing a standardized fetal echocardiography to accurately assess fetal cardiac, ventricular, and atrial dimensions. Parametric regressions were tested to model each measurement against gestational age from 18 to 41 weeks of gestation.

RESULTS

Nomograms were constructed for fetal cardiac dimensions (transverse and longitudinal diameters and areas) of the whole heart, atria, and ventricles, as well as myocardial wall thicknesses. All dimensions showed a progressive increase with gestational age. The best model for most parameters was a second-degree linear polynomial. Fetal cardiac, ventricular, and atrial diameters and areas were successfully obtained in 98.6% of the fetuses, while myocardial wall thicknesses could be obtained in 96.5% of the population. The results showed excellent interobserver and intraobserver reproducibility (intraclass correlation coefficient, ICC > 0.811 and ICC > 0.957, respectively).

CONCLUSIONS

We provide standardized and comprehensively evaluated reference values for fetal cardiac morphometric parameters across gestation in a low-risk population. These no mograms would enable the early identification of different patterns of fetal cardiac remodeling.

Maternal steroid therapy for fetuses with immune-mediated complete atrioventricular block: a systematic review and meta-analysis

INTRODUCTION

To explore the effect of maternal fluorinated steroid therapy on fetuses affected by immune-mediated complete atrio-ventricular block (CAVB) in utero.

MATERIAL AND METHODS

Pubmed, Embase, Cinahl, and ClinicalTrials.gov databases were searched. Only studies reporting the outcome of fetuses with immune CAVB diagnosed on prenatal ultrasound without any cardiac malformations and treated with fluorinated steroids compared to those not treated were included. The primary outcome observed was the regression of CAVB; secondary outcomes were need for pacemaker insertion, overall mortality, defined as the occurrence of either intrauterine (IUD) or neonatal (NND) death, IUD, NND, termination of pregnancy (TOP). Furthermore, we assessed the occurrence of all these outcomes in hydropic fetuses compared to those without hydrops at diagnosis. Meta-analyses of proportions using random effect model and meta-analyses using individual data random-effect logistic regression were used to combine data.

RESULTS

Eight studies (162 fetuses) were included. The rate of regression was 3.0% (95%CI 0.2-9.1) in fetuses treated and 4.3% (95%CI 0.4-11.8) in those not treated, with no difference between the two groups (odds ratio (OR): 0.9, 95%CI 0.1-15.1). Pacemaker at birth was required in 71.5% (95%CI 56.0-84.7) of fetuses-treated and 57.8% (95%CI 40.3-74.3) of those not treated (OR: 9, 95%CI 0.4-3.4). There was no difference in the overall mortality rate (OR: 0.5, 95%CI 0.9-2.7) between the two groups; in hydropic fetuses, mortality occurred in 76.2% (95%CI 48.0-95.5) of the treated and in 23.8% (95%CI 1.2-62.3) of the untreated group, while in those without hydrops the corresponding figures were 8.9% (95%CI 2.0-20.3) and 12% (95%CI 8.7-42.2), respectively. Improvement or resolution of hydrops during pregnancy occurred in 76.2% (95%CI 48.0-95.5) of cases treated and in 23.3% (95%CI 1.2-62.3) of those nontreated with fluorinated steroids.

CONCLUSIONS

The findings from this systematic review do not suggest a potential positive contribution of antenatal steroid therapy in improving the outcome of fetuses with immune CAVB.

Long-term exposure to high altitude hypoxia during pregnancy increases fetal heart susceptibility to ischemia/reperfusion injury and cardiac dysfunction

BACKGROUND

High altitude hypoxia (HAH) exposure affects fetal development. However, the fetal cardiovascular responses to the HAH are not well understood. We have tested the hypothesis that long-term HAH exposure alters the hypoxia/ischemia-sensitive gene expressions, leading to an increase in fetal heart susceptibility to ischemia/reperfusion (I/R) injury and cardiac dysfunction.

METHODS

Time-dated pregnant sheep were exposed to high-altitude (3820 m) or were maintained at sea level (~300 m) for 110 days. Fetal hearts were isolated from the near-term ewes and subjected to I/R in a Langendorff preparation.

RESULTS

HAH decreased the fetal body and heart weights in the female but not male fetuses. HAH had no effect on the left ventricle (LV) function at baseline, but increased the LV infarct size and attenuated the post-ischemic recovery of LV function in both male and female fetuses, as compared with the normoxic groups. HAH increased the protein levels of hypoxia-inducible factor (HIF)-1α and DNA methyltransferases type 3b (DNMT3b), but attenuated protein kinase C epsilon (PKCε) levels in the fetal hearts. AHA induced a 4.3 fold increase of miR-210 in the males and a 2.9 fold increase in female hearts. In addition, HAH had no effect on mTOR protein and phosphorylation levels but increased the autophagy biomarker, LC3B-II protein levels and LC3B-II/LC3B-I ratio in the fetal hearts.

CONCLUSION

The results suggest that gestational HAH exposure induces in utero programming of the hypoxia/ischemia-sensitive gene expression pattern in the developing heart and increases cardiac susceptibility to I/R injury.

Dynamic fetal cardiovascular magnetic resonance imaging using Doppler ultrasound gating

BACKGROUND

Fetal cardiovascular magnetic resonance (CMR) imaging may provide a valuable adjunct to fetal echocardiography in the evaluation of congenital cardiovascular pathologies. However, dynamic fetal CMR is difficult due to the lack of direct in-utero cardiac gating. The aim of this study was to investigate the effectiveness of a newly developed Doppler ultrasound (DUS) device in humans for fetal CMR gating.

METHODS

Fifteen fetuses (gestational age 30-39 weeks) were examined using 1.5 T CMR scanners at three different imaging sites. A newly developed CMR-compatible DUS device was used to generate gating signals from fetal cardiac motion. Gated dynamic balanced steady-state free precession images were acquired in 4-chamber and short-axis cardiac views. Gating signals during data acquisition were analyzed with respect to trigger variability and sensitivity. Image quality was assessed by measuring endocardial blurring (EB) and by image evaluation using a 4-point scale. Left ventricular (LV) volumetry was performed using the single-plane ellipsoid model.

RESULTS

Gating signals from the fetal heart were detected with a variability of 26 ± 22 ms and a sensitivity of trigger detection of 96 ± 4%. EB was 2.9 ± 0.6 pixels (4-chamber) and 2.5 ± 0.1 pixels (short axis). Image quality scores were 3.6 ± 0.6 (overall), 3.4 ± 0.7 (mitral valve), 3.4 ± 0.7 (foramen ovale), 3.6 ± 0.7 (atrial septum), 3.7 ± 0.5 (papillary muscles), 3.8 ± 0.4 (differentiation myocardium/lumen), 3.7 ± 0.5 (differentiation myocardium/lung), and 3.9 ± 0.4 (systolic myocardial thickening). Inter-observer agreement for the scores was moderate to very good (kappa 0.57-0.84) for all structures. LV volumetry revealed mean values of 2.8 ± 1.2 ml (end-diastolic volume), 0.9 ± 0.4 ml (end systolic volume), 1.9 ± 0.8 ml (stroke volume), and 69.1 ± 8.4% (ejection fraction).

CONCLUSION

High-quality dynamic fetal CMR was successfully performed using a newly developed DUS device for direct fetal cardiac gating. This technique has the potential to improve the utility of fetal CMR in the evaluation of congenital pathologies.

Prenatal Diagnosis of Dextrocardia with Complex Congenital Heart Disease Using Fetal Intelligent Navigation Echocardiography (FINE) and a Literature Review

Fetal dextrocardia is a type of cardiac malposition where the major axis from base to apex points to the right side. This condition is usually associated with a wide spectrum of complex cardiac defects. As a result, dextrocardia is conceptually difficult to understand and diagnose on prenatal ultrasound. The advantage of four-dimensional sonography with spatiotemporal image correlation (STIC) is that this modality can facilitate fetal cardiac examination. A novel method known as fetal intelligent navigation echocardiography (FINE) allows automatic generation of nine standard fetal echocardiography views in normal hearts by applying intelligent navigation technology to STIC volume datasets. In fetuses with congenital heart disease, FINE is also able to demonstrate abnormal cardiac anatomy and relationships when there is normal cardiac axis and position. However, this technology has never been applied to cases of cardiac malposition. We report herein for the first time, a case of fetal dextrocardia and situs solitus with complex congenital heart disease in which the FINE method was invaluable in diagnosing multiple abnormalities and defining complex anatomic relationships. We also review the literature on prenatal sonographic diagnosis of dextrocardia (with an emphasis on situs solitus), as well as tricuspid atresia with its associated cardiac features.

Consistent reconstruction of 4D fetal heart ultrasound images to cope with fetal motion

PURPOSE

4D ultrasound imaging of the fetal heart relies on reconstructions from B-mode images. In the presence of fetal motion, current approaches suffer from artifacts, which are unrecoverable for single sweeps.

METHODS

We propose to use many sweeps and exploit the resulting redundancy to automatically recover from motion by reconstructing a 4D image which is consistent in phase, space, and time. An interactive visualization framework to view animated ultrasound slices from 4D reconstructions on arbitrary planes was developed using a magnetically tracked mock probe.

RESULTS

We first quantified the performance of 10 4D reconstruction formulations on simulated data. Reconstructions of 14 in vivo sequences by a baseline, the current state-of-the-art, and the proposed approach were then visually ranked with respect to temporal quality on orthogonal views. Rankings from 5 observers showed that the proposed 4D reconstruction approach significantly improves temporal image quality in comparison with the baseline. The 4D reconstructions of the baseline and the proposed methods were then inspected interactively for accessibility to clinically important views and rated for their clinical usefulness by an ultrasound specialist in obstetrics and gynecology. The reconstructions by the proposed method were rated as 'very useful' in 71% and were statistically significantly more useful than the baseline reconstructions.

CONCLUSIONS

Multi-sweep fetal heart ultrasound acquisitions in combination with consistent 4D image reconstruction improves quality as well as clinical usefulness of the resulting 4D images in the presence of fetal motion.

Role of Echocardiography in Prenatal Screening of Congenital Heart Diseases and its Correlation with Postnatal Outcome

INTRODUCTION

Congenital Heart Defects (CHDs) are one of the most common forms of congenital anomalies. Fetal echocardiography performed during second trimester aims at early diagnosis of congenital heart disease which is instrumental in proper planning of delivery, perinatal care and counselling of parents.

AIM

To evaluate the role of fetal echocardiography in prenatal screening of CHDs and to study the role of associated extracardiac anomalies.

MATERIALS AND METHODS

This was a hospital based prospective and correlative type of study, done over a period of one year. Antenatal screening of fetal heart was done in mid-trimester high and low risk pregnancies. The prenatal echo findings were co-related with postnatal findings in case of any abnormality detected. The extra-cardiac anomalies associated with positive cases were evaluated and studied for their impact on postnatal outcome.

RESULTS

A total of 1200 pregnancies were screened out of which 672 were low risk and 528 were high risk. The cases with abnormal echo findings were followed postnatally. The overall incidence of CHD in study population was 15 per 1000. The incidence in high and low risk pregnancies were 16.3 and 13.25 per thousand respectively. Complete agreement of 68.17% was found between prenatal and postnatal findings. The most frequent Extra-Cardiac Anomalies (ECA) in cases with CHD was of musculoskeletal system. The CHD cases with ECA were significantly of low birth weight, born preterm and delivered by Lower Segment Caesarean Section (LSCS).

CONCLUSION

Fetal heart is the most overlooked part in every routine anomaly scan. We conclude that fetal echocardiography should be an integral part of every second trimester anomaly scan for all pregnant females irrespective of their risk factors. The associated ECAs are another factor that causes increased mortality both in antenatal and neonatal life, again warranting an early fetal echo.

Reference Ranges of Fetal Cardiac Biometric Parameters Using Three-Dimensional Ultrasound with Spatiotemporal Image Correlation M Mode and Their Applicability in Congenital Heart Diseases

To determine reference values for fetal heart biometric parameters using the spatiotemporal image correlation (STIC) M mode and their applicability in congenital heart diseases (CHDs). A cross-sectional prospective study was conducted with 300 singleton pregnancies between 20 and 33 + 6 weeks of gestation. Right ventricular wall thickness (RVWT), interventricular septum thickness (IVST), and left ventricular wall thickness (LVWT) were measured off-line using the STIC-M mode with the cursor perpendicular to the interventricular septum. Polynomial regressions adjusted with the coefficient of determination (R ²) were performed. The curves were applied to 14 fetuses with structural CHD. For the reproducibility calculations, the concordance correlation coefficient (CCC) was used. The mean RVWT, IVST, and LVWT were 0.34 ± 0.09 cm, 0.28 ± 0.09 cm, and 0.30 ± 0.07 cm, respectively. There was correlation between RVWT, IVST, and LVWT and gestational age (GA): RVWT = -0.002 + 0.013 × GA (R ² = 0.33), IVST = -0.011 + 0.011 × GA (R ² = 0.25), and LVWT = 0.056 + 0.009 × GA (R ² = 0.26). RVWT, IVST, and LVWT were altered (<5th or >95th percentile) in 5/14, 5/14, and 7/14 of the fetuses with CHD, respectively. For RVWT, IVST, and LVWT, intra-observer (CCC = 0.86, 0.85, and 0.87, respectively) and inter-observer (CCC = 0.86, 0.86, and 0.86, respectively) reproducibility were good/moderate. The reference ranges determined for fetal heart biometric parameters using STIC-M had good intra- and inter-observer reproducibility and were applicable to fetuses with CHD.

First reported case of fetal aortic valvuloplasty in Asia

Prenatal intervention of severe fetal aortic valve stenosis by ultrasound-guided percutaneous balloon valvuloplasty has been performed to prevent the progression to hypoplastic left heart syndrome, and achieve biventricular circulation in neonates. Here we report a case of fetal aortic valvuloplasty prenatally diagnosed with aortic stenosis at 24 weeks of gestation and showed worsening features on a follow-up echocardiography. Prenatal aortic valvuloplasty was performed at 29 weeks of gestation, and was a technical success. However, fetal bradycardia sustained, and an emergency cesarean delivery was performed. To the best of our knowledge, this is the first reported case of fetal aortic valvuloplasty which was performed in Asia.

Persistent Left Superior Vena Cava Connected to the Coronary Sinus in the Fetus: Effects on Cardiac Structure and Flow Dynamics

Ventricular size discrepancy may be due to a persistent left superior vena cava (PLSVC) in utero. We sought to investigate for differences in cardiac structure measures and hemodynamics between fetuses with isolated PLSVC connected to the coronary sinus (CS) and normal. Fetuses diagnosed with isolated PLSVC in the second and third trimester were enrolled. We defined two groups: group 1, twenty-five fetuses in the second trimester (22-27 W + 6d); group 2, twenty-two fetuses in the third trimester (28-39 W + 6d). Fifty-three fetuses without intra-cardiac or extra-cardiac anomalies and gestation age-matched were divided into normal control groups: group 3, 28 fetuses in the second trimester; group 4, 25 fetuses in the third trimester. Parameters of cardiac structure and hemodynamics were measured, including: left- and right-side heart size, the diameter of foramen ovale, aorta (AO), aortic isthmus and pulmonary artery (PA), and ratios of cardiac structure RV/LV, RA/LA and PA/AO were calculated. Hemodynamic parameters measured included: flow velocity across mitral valve, tricuspid valve and foramen ovale. In the second trimester, the ratio of RV/LV and PA/AO of the PLSVC fetuses was significantly larger than normal, while the AO diameter, aortic isthmus diameter were smaller than normal (P < 0.05). However, in the third trimester, only the ratio of PA/AO of the PLSVC fetuses was significantly larger, and the aortic isthmus diameter was still smaller than normal (P < 0.05). Isolated PLSVC connecting to the CS is associated with differences in cardiac structure size from normal. These differences appear to diminish with gestational age. A dilated CS may have an influence on development of fetal left heart structures.

MR imaging of fetal cardiac malposition and congenital cardiovascular anomalies on the four-chamber view

Fetal echocardiography is the method of choice to visualize the fetal congenital cardiovascular anomalies. However, there are some disadvantages. Fetal cardiac magnetic resonance imaging (MRI) has the potential to complement ultrasound in detecting congenital cardiovascular anomalies. This pictorial review draws on our experience about fetal cardiac MRI; it describes the four-chamber view on fetal cardiac MRI and important clues on an abnormal four-chamber view to the diagnosis of fetal congenital cardiovascular anomalies.

Fetal and maternal cardiac responses to physical activity and exercise during pregnancy

Since the 1970s, researchers have studied the influence of exercise during pregnancy on offspring heart development. With the knowledge and current evidence of fetal programming effects, research has demonstrated that exercise is safe and beneficial for mother, fetus, and neonate. Predominantly, research has focused on maternal and fetal cardiac adaptations related to aerobic exercise during pregnancy; less is known regarding the effects of resistance or combination (aerobic and resistance) training during pregnancy. Ongoing research is focusing on fetal responses to different intensity, duration and modes of maternal exercise throughout pregnancy. This article will summarize our current state of knowledge regarding the influence of exercise intensity, duration, and modes during pregnancy on maternal and fetal cardiac responses.

The protective effect of ursodeoxycholic acid in an in vitro model of the human fetal heart occurs via targeting cardiac fibroblasts

Bile acids are elevated in the blood of women with intrahepatic cholestasis of pregnancy (ICP) and this may lead to fetal arrhythmia, fetal hypoxia and potentially fetal death in utero. The bile acid taurocholic acid (TC) causes abnormal calcium dynamics and contraction in neonatal rat cardiomyocytes. Ursodeoxycholic acid (UDCA), a drug clinically used to treat ICP, prevents adverse effects of TC. During development, the fetus is in a state of relative hypoxia. Although this is essential for the development of the heart and vasculature, resident fibroblasts can transiently differentiate into myofibroblasts and form gap junctions with cardiomyocytes in vitro, resulting in cardiomyocyte depolarization. We expanded on previously published work using an in vitro hypoxia model to investigate the differentiation of human fetal fibroblasts into myofibroblasts. Recent evidence shows that potassium channels are involved in maintaining the membrane potential of ventricular fibroblasts and that ATP-dependent potassium (KATP) channel subunits are expressed in cultured fibroblasts. KATP channels are a valuable target as they are thought to have a cardioprotective role during ischaemic and hypoxic conditions. We investigated whether UDCA could modulate fibroblast membrane potential. We established the isolation and culture of human fetal cardiomyocytes and fibroblasts to investigate the effect of hypoxia, TC and UDCA on human fetal cardiac cells. UDCA hyperpolarized myofibroblasts and prevented TC-induced depolarisation, possibly through the activation of KATP channels that are expressed in cultured fibroblasts. Also, similar to the rat model, UDCA can counteract TC-induced calcium abnormalities in human fetal cultures of cardiomyocytes and myofibroblasts. Under normoxic conditions, we found a higher number of myofibroblasts in cultures derived from human fetal hearts compared to cells isolated from neonatal rat hearts, indicating a possible increased number of myofibroblasts in human fetal hearts. Hypoxia further increased the number of human fetal and rat neonatal myofibroblasts. However, chronically administered UDCA reduced the number of myofibroblasts and prevented hypoxia-induced depolarisation. In conclusion, our results show that the protective effect of UDCA involves both the reduction of fibroblast differentiation into myofibroblasts, and hyperpolarisation of myofibroblasts, most likely through the stimulation of potassium channels, i.e. KATP channels. This could be important in validating UDCA as an antifibrotic and antiarrhythmic drug for treatment of failing hearts and fetal arrhythmia.

Canine fetal echocardiography: correlations for the analysis of cardiac dimensions

The aim of this study was to develop regression models for correlation of canine fetal heart development with body size to characterize normal development or suggest cardiac anomalies. Twenty clinically healthy pregnant bitches, either brachycephalic and non-brachycephalic, were examined ultrasonographically. Transabdominal fetal echocardiography was conducted every 4 days from the beginning of cardiac chambers differentiation until parturition. Ten cardiac parameters were measured: length, width and diameter of the heart; heart area; left and right ventricular dimensions; left and right atrial dimensions; and aortic and pulmonary artery diameter. Femoral length, biparietal diameter and abdominal cross-sectional area were also recorded. Regression equations were developed for each parameter of fetal body size, and linear and logarithmic models were compared. The model with the highest correlation coefficient was chosen to produce equations to calculate relative dimensions based on the correlations. Only the left-ventricular chamber differed between the two racial groups. Biparietal diameter was the independent parameter that produced the highest correlation coefficient for the most fetal cardiac dimensions, although good correlations were also observed using femoral length and abdominal cross-sectional area. Heart width and heart diameter were used as surrogates of cardiac development, as these measurements showed the best statistical correlation. Quantitative evaluation of fetal cardiac structures can be used to monitor normal and abnormal cardiac development.

An unusual ultrasonographic manifestation of a fetal Ebstein anomaly

An Ebstein anomaly is a rare congenital heart defect defined by an inferior displacement of the septal and posterior leaflets of the tricuspid valve from the tricuspid annulus. This anomaly shows various ultrasonographic manifestations, thus making the prenatal diagnosis sometimes difficult. We here report a rare case of an Ebstein anomaly which was prenatally suspected as the absence of the tricuspid valve with functional pulmonary atresia because of non-visible tricuspid leaflets on an echocardiograph at 24 weeks of gestation. An emergency cesarean section was performed at 35 weeks of gestation as fetal hydrops were seen on a follow-up scan. Postnatal surgery confirmed Ebstein anomaly type-D which demonstrates an almost complete atrialization of the right ventricle with the exception of a small and infundibular component. Because of its rarity, prenatal findings of a type-D Ebstein anomaly have not been reported previously. We suggest from this first such case report that this anomaly should be considered as a possible diagnosis when the tricuspid leaflets are not well visualized.

Four-dimensional echocardiography with spatiotemporal image correlation and inversion mode for detection of congenital heart disease

The aim of this study was to evaluate the use of 4-D echocardiography with inversion mode and spatiotemporal image correlation (IM-STIC) in the detection of normal and abnormal fetal hearts. We retrospectively studied 112 normal fetuses and 16 fetuses with a confirmed diagnosis of congenital heart disease. Two volumes were acquired from each of the fetuses using transverse and sagittal sweeps. Volumes were reconstructed with IM-STIC. In normal fetuses, IM-STIC facilitated visualization of the interior structures of the fetal heart and great vessels. The visualization rates of intended planes obtained from IM-STIC 4D data ranged from 55% to 100%. In 16 fetuses with congenital heart disease, IM-STIC was able to display the cardiac malformations using digital casting. Some of the malformations were suspected during pre-natal 2-D echocardiography, and their pre-natal IM-STIC diagnoses were confirmed by post-natal echocardiography, surgery and/or autopsy. Hence, 4-D IM-STIC allows better visualization of complex congenital heart disease and should be considered a very useful addition to 2-D echocardiography.

Why more attentions to fetus in cases of intrahepatic cholestasis of pregnancy?

Intrahepatic cholestasis of pregnancy (ICP) is a peculiar disease in middle-late pregnancy with the pathological characteristics of hepatic capillary bile duct silts and is accompanied by clinical presentations of pruritus and bile acid (BA) elevation in serum. Maternal outcomes for patients diagnosed with ICP are usually good. However, fetal outcomes can be devastating with high frequencies of perinatal complications. Patients with ICP generally have an early delivery due to fetal complications. The current hypothesis is that ICP has higher frequencies of fetal complications due to high concentrations of BA which has toxic cellular effects to many organs. In lungs, it destroys the AT-II cells, decreasing phospholipids synthesis leading to the alveolar capillary permeability to increase and pulmonary surfactant to decrease. In heart, cholate can cross into the fetal compartment and causing fetal arrhythmias and decreased contractility. In the nervous system, high BAs can cause nerve cell denaturation and necrosis, mitochondria edema and membrane dissolve. In the placenta, high BA concentration can cause edema of the villous, decrease number of villous, intervillous thickening and balloon formation. In addition, high total BA can result in chorionic vein constriction and impaired fetal adrenal function.

Potential of magnetic resonance for imaging the fetal heart

Significant congenital heart disease (sCHD) affects 3.6 per 1000 births, and is often associated with extracardiac and chromosomal anomalies. Although early mortality has been substantially reduced and the rate of long-term survival has improved, sCHD is, after preterm birth, the second most frequent cause of neonatal infant death. The prenatal detection of cardiac and vascular abnormalities enables optimal parental counselling and perinatal management. Echocardiography (ECG) is the first-line examination and gold standard by which cardiac malformations are defined. However, adequate examination by an experienced healthcare provider with modern technical imaging equipment is required. In addition, maternal factors and the gestational age may lower the image quality. Fetal magnetic resonance imaging (MRI) has been implemented over the last several years and is already used in the clinical routine as a second-line approach to assess fetal abnormalities. MRI of the fetal heart is still not routinely performed. Nevertheless, fetal cardiac MRI has the potential to complement ultrasound in detecting cardiovascular malformations and extracardiac lesions. The present work reviews the potential of MRI to delineate the anatomy and pathologies of the fetal heart. This work also deals with the limitations and continuing developments designed to overcome the current problems in cardiac imaging, including fast fetal heart rates, the lack of ECG-gating, and the presence of fetal movements.

Three-dimensional HDlive rendering images of the fetal heart

Our objective is to describe our experience with reconstruction of normal fetal cardiac structures and congenital heart anomalies using the 3-D HDlive rendering mode with spatiotemporal image correlation (STIC). Four normal fetuses and three fetuses with congenital heart anomalies (Ebstein's anomaly, hypoplastic left heart syndrome and tetralogy of Fallot) at 25-35 wk of gestation were studied using the 3-D HDlive rendering mode with STIC. In normal fetuses, the natural appearance of the dynamic motion of the foramen ovale flap and both atrioventricular valves was clearly visualized in real time in the four-chamber view. Moreover, new, realistic sensations of each leaflet of atrioventricular valves and semilunar valves of the pulmonary artery were obtained in the en face view of both atrioventricular valves and great vessels. In the case of Ebstein's anomaly, the procedure rendered the natural and anatomically realistic appearance of significantly low attachment of the tricuspid valve and atrialized portion of the right ventricle. In hypoplastic left heart syndrome, thickened tricuspid and dysplastic pulmonary valves were clearly revealed. In tetralogy of Fallot, an overriding aorta and ventricular septal defect were realistically depicted. The 3-D HDlive rendering mode with STIC provides entirely new visual experiences for obstetricians and pediatric cardiologists owing to the anatomically realistic depiction of normal and abnormal fetal cardiac structures of the beating heart.

Technique of fetal echocardiography

Congenital heart disease is the most common abnormality in the human fetus. Fetal echocardiography has been used to detect the majority of cardiac defects, and it is now part of the routine screening method for fetal evaluation. In this article, we present standard ultrasonographic views of the normal fetal heart obtained during the second trimester, first-trimester fetal echocardiography findings, and a modified myocardial performance index.