Assessment of ventricular contractility in fetuses with an estimated fetal weight less than the tenth centile

Subclinical myocardial dysfunction among fetal growth restriction neonates: a case-control study

OBJECTIVES

To evaluate cardiac structural and functional changes in neonates with fetal growth restriction (FGR) compared to appropriate-for-gestational-age (AGA) neonates using conventional echocardiography, tissue Doppler imaging (TDI), and speckle tracking echocardiography.

METHOD

This case-control study included 85 FGR neonates and 75 non-FGR, weight adequate for gestational age neonates. Among these, 37 were symmetric FGR and 48 were asymmetric FGR. All the biophysical profiles of these newborns were assessed. An echocardiographic test was performed to evaluate cardiac dimension, Left ventricular ejection fraction (LV EF), Mitral valve Doppler flow velocities, myocardial performance index, tissue annular velocities, and LV global longitudinal strain (GLS).

RESULTS

Although LVEF was found to be within the normal range, mean EF was reduced among neonates with FGR than non-FGR controls (EF: 66.14 ± 3.85% vs 69.46 ± 3.58%; p < 0.001, in FGR and non-FGR, respectively). Furthermore, LV E/E' a measure of LV diastolic function was altered among both types of FGR neonates. Similarly, LV GLS was reduced among FGR neonates (LV GLS: -20.69 ± 2.7% vs -19.06 ± 2.9%; p < 0.001 in non-FGR and FGR, respectively).

CONCLUSION

FGR neonates exhibit significant alterations in cardiac geometry compared to AGA controls. FGR neonates also demonstrated a significant reduction in LV EF, FS, and LV global longitudinal strain, depicting failure to adapt to the increased cardiac workload after birth.

Fetuses with deceleration of growth improve their growth following maternal rest

OBJECTIVE

The purpose of this study was to determine if fetuses with deceleration of growth velocity resulting in an EFW <10th percentile increase their growth above the 10th percentile following 2 weeks of maternal rest in the left lateral recumbent position.

METHODS

This was a retrospective observational study of 265 fetuses with the prenatal diagnosis of an EFW <10th percentile. Fetuses were classified by four definitions of abnormal growth velocity: (1) a growth velocity less than 20 g/day, (2) 30 percentile decrease in the EFW, (3) 50 percentile decrease in the EFW, and (4) abnormal growth trajectory. Once the fetuses were identified with an EFW <10th percentile the patient was requested to begin 2 weeks of rest in the left lateral recumbent position during her waking hours following which the EFW was reassessed 2 week later to determine the effect of maternal rest on the EFW.

RESULTS

Irrespective of the four types of decreased growth velocity described in the methods section, there was as significant increase (p < 0.001) in the EFW following 2 weeks of maternal rest as follows: (1) growth less than 20 g/day (75%); (2) decrease of 30 or more EFW percentiles (79%); (3) decrease of 50 or more EFW percentiles (64%); and abnormal growth trajectory (77%).

CONCLUSIONS

This suggests an important role of increased maternal cardiac output as the result of resting in the left lateral recumbent position that may be associated with improved fetal growth. These observations should be the basis for future prospective randomized trials to test this hypothesis.

Reproducibility Analysis of Two Speckle Tracking Software for the Antenatal Semiautomated Assessment of the Fetal Cardiac Function

INTRODUCTION

Speckle tracking echocardiography is a non-Doppler modality allowing the semiautomated evaluation of the fetal cardiac function by tracking the speckles of the endocardial borders. Little evidence is available on the evaluation and comparison of different software for the functional assessment of the fetal heart by means of speckle tracking echocardiography. The aim of this study was to evaluate the reproducibility and agreement of two different proprietary speckle tracking software for the prenatal semiautomated assessment of the fetal cardiac function.

METHODS

The prospective study including non-anomalous fetuses was referred for different indications at two tertiary academic units in Italy (University of Parma) and Spain (University of Barcelona). Two-dimensional clips of the four-chamber view of the fetal heart were acquired by two dedicated operators using high-end ultrasound machines with a frame rate higher than 60 Hz. The stored clips were pseudo-anonymized and shared between the collaborating units. Functional echocardiographic analyses were independently performed using the two proprietary software (TomTec GmbH and FetalHQ®) by the same operators. Inter-software reproducibility of the endocardial global longitudinal strain (EndoGLS) and fractional area change (FAC) of the left (LV) and the right ventricles (RV) and ejection fraction (EF) of the LV were evaluated by the intraclass correlation coefficient (ICC).

RESULTS

Forty-eight fetuses were included at a median of 31+2 (21+6-40+3) gestational weeks. Moderate reproducibility was found for the functional parameters of the LV: EndoGLS (Pearson's correlation 0.456, p < 0.01; ICC 0.446, 95% CI: 0.189-0.647, p < 0.01); EF (Pearson's correlation 0.435, p < 0.01; ICC 0.419, 95% CI: 0.156-0.627, p < 0.01); FAC (Person's correlation 0.484, p < 0.01; ICC 0.475, 95% CI: 0.223-0.667, p < 0.01). On the contrary, RV functional parameters showed poor reproducibility between the two software: EndoGLS (Pearson's correlation 0.383, p = 0.01; ICC 0.377, 95% CI: 0.107-0.596, p < 0.01) and FAC (ICC 0.284, 95% CI: 0.003-0.524, p = 0.02).

CONCLUSION

Our results demonstrate a moderate reproducibility of the speckle tracking analysis of the LV using TomTec GmbH and FetalHQ®, with poor reproducibility for RV analysis.

Umbilical Vein Flows and Cardiac Size, Shape, and Ventricular Contractility in Fetuses With Estimated Weight Less-Than 10th Centile

OBJECTIVES

In a cohort of patients with estimated fetal weights (EFWs) <10th centile, we aimed 1) to compare the prevalence of abnormalities of fetal 4-chamber view (4CV) cardiac size, shape, and ventricular contractility in fetal growth restricted (FGR) and small-for-gestational-age (SGA) fetuses and 2) to compare umbilical vein flow (UVF) measurements to standard Doppler surveillance in predicting abnormalities of cardiac function.

METHODS

Prospective observational cohort study of fetuses with EFW <10th percentile. Measurements of size and shape used were 4CV transverse width, 4CV cardiac area, 4CV global sphericity index, and right-to-left ventricular mid-chamber width ratio. Variables of contractility used were fractional shortening change at the mid-ventricle chamber, global longitudinal strain, fractional area change, and left ventricular cardiac output. The UVF and standard Doppler surveillance including umbilical artery (UA), middle cerebral artery, and cerebroplacental ratio (CPR) were collected. Control data were from previously published studies.

RESULTS

A total of 95 fetuses with EFWs <10th centile were included in the study. The rates of abnormalities of cardiac size and shape and ventricular contractility were all significantly elevated compared with normally grown control fetuses but similar between FGR and SGA fetuses. In a subset of 76 patients with UVF data, evaluation UVF identified more patients with any abnormality of contractility compared with UA (37.9 vs 17.2%, P = .02).

CONCLUSIONS

The addition of UVF doubled the detection rate of ventricular contractility abnormalities. The addition of UVF should be considered in the surveillance of FGR and SGA fetuses to further stratify the severity of hypoxemia and to identify those at greater risk for future cardiovascular dysfunction.

Association of Amniotic Fluid Volume and Fetal Cardiac and Cerebrovascular Parameters in Fetal Growth Restriction

OBJECTIVES

To investigate the prevalence of oligohydramnios, brain sparing, and cardiac dysfunction among a cohort of fetal growth restriction (FGR).

METHODS

To assess the prevalence of oligohydramnios amongst a large sample of FGR fetuses, we screened a database of ultrasounds of FGR pregnancies from our maternal-fetal medicine clinics (clinical cohort) for diminished amniotic fluid volume. Using a threshold of a maximum vertical pocket (MVP) of <2 cm for "oligohydramnios," and 2 to 3 cm as a "reduced fluid" group, trends of Doppler values and cardiac parameters were assessed from pregnancies in an ongoing research study (comprehensive cohort).

RESULTS

In the clinical cohort, oligohydramnios was identified in only 2/229 (0.8%) and reduced fluid in 19/229 (8%). In the comprehensive cohort, oligohydramnios was seen in 3/126 (2.3%) and reduced fluid in 14/126 (11.1%). A high rate of cardiac and Doppler abnormalities were observed in the oligohydramnios group of the comprehensive cohort. The patients with oligohydramnios had a distinctly different cardiac phenotype with small (2/3 with cardiac area <5th%) (P = 0.01) and round (3/3 with global sphericity index <5th%) (P = 0.02) hearts.

CONCLUSION

Oligohydramnios, when present with FGR, is accompanied by high rates of cerebral and cardiovascular abnormalities.

Reference Ranges and Development Patterns of Fetal Myocardial Function Using Speckle Tracking Echocardiography in Healthy Fetuses at 17 to 24 Weeks of Gestation

OBJECTIVE

The purposes of the study were to develop reference ranges and maturation patterns of fetal cardiac function parameters measured by speckle tracking echocardiography (STE) using multiple biometric variables at 17 to 24 weeks' gestation among Thai fetuses and to compare with other previous reports.

STUDY DESIGN

The four-chamber view of the fetal heart in 79 healthy fetuses was suitably analyzed by STE to establish the best-fit regression model. The 95% reference intervals and Z-score equations of fetal cardiac function parameters were computed.

RESULTS

The fractional area change of both ventricles, left ventricular (LV) end-diastolic and end-systolic volumes, LV stroke volume, LV cardiac output (CO), and LV CO per kilogram were all increased according to gestational age (GA) and five fetal biometric measurements. However, the global longitudinal strain, basal-apical length fractional shortening (BAL-FS), BAL annular free wall and septal wall FS, BAL free wall and septal wall annular plane systolic excursions, 24-segment transverse width FS, as well as LV ejection fraction were all independent of GA or other somatic characteristics. There were varying development patterns between fetal right and left ventricles of these cardiac function indices across the gestation period.

CONCLUSION

Our study created Z-score and corresponding centile calculators, 5th and 95th centile reference tables, and corresponding graphs and determined the normal evolution across gestation using multiple somatic growth and age variables between 17 and 24 gestational weeks. These nomograms serve as an essential prerequisite for quantitatively evaluating fetal cardiac contractility and allow for precisely detecting early changes in the fetal heart function.

KEY POINTS

· Most fetal cardiac function measurements were correlated with all the independent variables.. · Fetal ventricular function parameters have their own characteristic maturation changes.. · Racial variability may not occupy an important place for fetal myocardial function during these GA..

Post-COVID-19 Fetal Cardiac Morphology and Systolic Evaluation in Infected Pregnant Women by Fetal Heart Quantification Technology

OBJECTIVES

Due to the government's liberalization of epidemic control, the current 2019 novel coronavirus disease (COVID-19) has started to spread widely within China. This study aimed to use the fetal heart quantification (fetal HQ) technique to assess the cardiac function and morphology of the fetuses of pregnant women diagnosed with COVID-19 in the early stages of pregnancy.

METHODS

Exactly 86 pregnant women diagnosed with COVID-19 infection in early pregnancy (COVID-19 group) and 90 healthy pregnant women (control group) who underwent fetal echocardiography were prospectively included in this study. The fetal HQ technique was applied to compare the differences in the global sphericity index (GSI), global strain values (GS), fractional area change (FAC), and 24-segment fractional shortening (FS) of the left and right ventricles, between the COVID-19 group and the control group.

RESULTS

Compared with the control group, the differences in GS and 24-segment FS of the left ventricle in the COVID-19 group were not statistically significant. However, the COVID-19 group showed lower GSI values compared with the control group (1.24 vs 1.28). FAC (48.12%) of the left ventricle and GS (-23.55%), FAC (41.74%) of the right ventricle in the COVID-19 group were reduced compared with FAC (50.50%) of the left ventricle and GS (-27.63%), FAC (46.01%) of the right ventricle in the control group. Segmental analysis revealed reduced FS in segments 20-24 in the COVID-19 group compared with the control group. Right ventricular GS was an independent predictor of adverse pregnancy outcome with an optimal cutoff value of -18.66%.

CONCLUSIONS

The results suggest that COVID-19 infection in early pregnancy may have a negative impact on fetal cardiac morphology and function. Fetal HQ may offer a new assessment method for the early identification of fetal cardiac alterations in pregnant women infected with COVID-19.

How automated techniques ease functional assessment of the fetal heart: Applicability of two-dimensional speckle-tracking echocardiography for comprehensive analysis of global and segmental cardiac deformation using fetalHQ®

BACKGROUND

Prenatal echocardiographic assessment of fetal cardiac function has become increasingly important. Fetal two-dimensional speckle-tracking echocardiography (2D-STE) allows the determination of global and segmental functional cardiac parameters. Prenatal diagnostics is relying increasingly on artificial intelligence, whose algorithms transform the way clinicians use ultrasound in their daily workflow. The purpose of this study was to demonstrate the feasibility of whether less experienced operators can handle and might benefit from an automated tool of 2D-STE in the clinical routine.

METHODS

A total of 136 unselected, normal, singleton, second- and third-trimester fetuses with normofrequent heart rates were examined by targeted ultrasound. 2D-STE was performed separately by beginner and expert semiautomatically using a GE Voluson E10 (FetalHQ®, GE Healthcare, Chicago, IL). Several fetal cardiac parameters were calculated (end-diastolic diameter [ED], sphericity index [SI], global longitudinal strain [EndoGLS], fractional shortening [FS]) and assigned to gestational age (GA). Bland-Altman plots were used to test agreement between both operators.

RESULTS

The mean maternal age was 33 years, and the mean maternal body mass index prior to pregnancy was 24.78 kg/m2. The GA ranged from 16.4 to 32.0 weeks (average 22.9 weeks). Averaged endoGLS value of the beginner was -18.57% ± 6.59 percentage points (pp) for the right and -19.58% ± 5.63 pp for the left ventricle, that of the expert -14.33% ± 4.88 pp and -16.37% ± 5.42 pp. With increasing GA, right ventricular endoGLS decreased slightly while the left ventricular was almost constant. The statistical analysis for endoGLS showed a Bland-Altman-Bias of -4.24 pp ± 8.06 pp for the right and -3.21 pp ± 7.11 pp for the left ventricle. The Bland-Altman-Bias of the ED in both ventricles in all analyzed segments ranged from -.49 mm ± 1.54 mm to -.10 mm ± 1.28 mm, that for FS from -.33 pp ± 11.82 pp to 3.91 pp ± 15.56 pp and that for SI from -.38 ± .68 to -.15 ± .45.

CONCLUSIONS

Between both operators, our data indicated that 2D-STE analysis showed excellent agreement for cardiac morphometry parameters (ED and SI), and good agreement for cardiac function parameters (EndoGLS and FS). Due to its complexity, the application of fetal 2D-STE remains the domain of scientific-academic perinatal ultrasound and should be placed preferably in the hands of skilled operators. At present, from our perspective, an implementation into clinical practice "on-the-fly" cannot be recommended.

Maternal rest improves growth in small-for-gestational-age fetuses (<10th percentile)

BACKGROUND

Optimal management of fetuses diagnosed as small for gestational age based on an estimated fetal weight of <10th percentile represents a major clinical problem. The standard approach is to increase fetal surveillance with serial biometry and antepartum testing to assess fetal well-being and timing of delivery. Observational studies have indicated that maternal rest in the left lateral position improves maternal cardiac output and uterine blood flow. However, maternal bed rest has not been recommended based on the results of a randomized clinical trial that showed that maternal rest does not improve fetal growth in small-for-gestational-age fetuses. This study was conducted to revisit this question.

OBJECTIVE

This study aimed to determine whether maternal bed rest was associated with an increase in the fetal biometric parameters that reflect growth after the diagnosis of a small-for-gestational-age fetus.

STUDY DESIGN

A retrospective study was conducted on fetuses who were diagnosed as small for gestational age because of an estimated fetal weight of <10th percentile for gestational age. The mothers were asked to rest in the left lateral recumbent position. Fetal biometry was performed 2 weeks after the diagnosis. All fetuses before entry into the study had a previous ultrasound that demonstrated an estimated fetal weight of >10th percentile. To assess the response to bed rest, the change in fetal biometric parameters (estimated fetal weight, head circumference, abdominal circumference, and femur length) after the recommendation of bed rest was computed for 2 periods: (1) before the diagnosis of a weight of <10th percentile vs at the time of diagnosis of a weight of <10th percentile and (2) at the time of diagnosis of a weight of <10th percentile vs 2 weeks after maternal bed rest. For repeated measures, proportions were compared using the McNemar test, and percentile values were compared using the Bonferroni Multiple Comparison Test. A P value of <.05 was considered significant. To describe changes in the estimated fetal weight without bed rest, 2 control groups in which the mothers were not placed on bed rest after the diagnosis of a small-for-gestational-age fetus were included.

RESULTS

A total of 265 fetuses were observed before and after maternal bed rest. The following were observed in this study: (1) after 2 weeks of maternal rest, 199 of 265 fetuses (75%) had a fetal weight of >10th percentile; (2) the median fetal weight percentile increased from 6.8 (interquartile range, 4.4-8.4) to 18.0 (interquartile range, 9.5-29.5) after 2 weeks of bed rest; (3) similar trends were noted for the head circumference, abdominal circumference, and femur length. In the groups of patients who were not asked to be on bed rest, a reassignment to a weight of >10th percentile at a follow-up examination only occurred in 7 of 37 patients (19%) in the Texas-Michigan group and 13 of 111 patients (12%) in the Colorado group compared with the bed rest group (199/265 [75%]) (P<.001).

CONCLUSION

Patients who were prescribed 2 weeks of bed rest after the diagnosis of a fetal weight of <10th percentile had an increase in weight of >10th percentile in 199 of 265 fetuses (75%). This increase in fetal weight was significantly higher than that in the 2 control groups in which bed rest was not prescribed. This observation suggests that bed rest improves fetal growth in a subset of patients.

Subclinical cardiac impairments in fetuses conceived through assisted reproductive technology by speckle tracking echocardiography

OBJECTIVES

To evaluate the changes of cardiac morphology and function in fetuses conceived through assisted reproductive technologies (ART) by speckle tracking echocardiography.

METHODS

A retrospective study was conducted in 101 spontaneously conceived (SC) fetuses and 99 ART-conceived ones. Fetal echocardiography was performed, fetal cardiac morphology and function were analyzed using two-dimensional speckle tracking software, including global sphericity index (GSI), global longitudinal strain (GLS), fractional area change (FAC) of the left and right ventricles, as well as segmental sphericity index (SI), end-diastolic diameter (ED), and fractional shortening (FS) in 24 segments.

RESULTS

Compared to the SC fetuses, the ART-conceived fetuses exhibited decreased GSI (median [interquartile range], 1.22 [1.16-1.27] vs. 1.18 [1.11-1.24], p=0.007), decreased right ventricular GLS (24.9 [21.5-27.6] vs. 23.2 [20.4-26.8], p=0.026), and decreased right ventricular FAC (mean ± standard deviation, 39.7 ± 6.4 vs. 37.2 ± 7.1, p=0.003). Analysis of the 24 segments showed that ART-conceived fetuses had reduced SI in the apical segments of right ventricle and increased ED in several segments of the right ventricle.

CONCLUSIONS

Fetuses conceived through ART had a more spherical shape of the global heart and predominantly right-sided cardiac remodeling and systolic function impairment.

Fetal Left Ventricle Function Evaluated by Two-Dimensional Speckle-Tracking Echocardiography across Clinical Stages of Severity in Growth-Restricted Fetuses

Fetal growth restriction (FGR) can result in adverse perinatal outcomes due to cardiac dysfunction. This study used 2D speckle-tracking echocardiography to assess left ventricle (LV) longitudinal strain across FGR severity stages. A prospective longitudinal cohort study measured global (GLS) and segmental LV longitudinal strain in FGR fetuses, with evaluations conducted at various time points. FGR was classified into subtypes based on published criteria using fetal weight centile and Doppler parameters. A linear mixed model was employed to analyze repeated measures and compare Z-score measurements between groups throughout gestational age. The study included 40 FGR fetuses and a total of 107 evaluations were performed: 21 from small for gestational age (SGA), 74 from the FGR stage I, and 12 from the FGR stage ≥ II. The results indicate that SGA and stage I FGR fetuses exhibit higher LV GLS than stages ≥ II. Throughout gestation, SGA and FGR stage I fetuses showed similar behavior with consistently better LV GLS values when compared to FGR stages ≥ II. No significant differences were observed in LV GLS strain behavior between SGA and FGR stage I. In conclusion, all FGRs show signs of early cardiac dysfunction, with severe cases demonstrating significantly a lower LV GLS when compared to mild cases, suggesting deterioration of cardiac dysfunction with progression of fetal compromise.

Longitudinal Behavior of Left-Ventricular Strain in Fetal Growth Restriction

Fetal growth restriction (FGR) is associated with an increased risk of adverse outcomes resulting from adaptive cardiovascular changes in conditions of placental insufficiency, leading to cardiac deformation and dysfunction, which can be evaluated with 2D speckle tracking echocardiography (2D-STE). The aim of the present study was to evaluate whether reduced fetal growth is associated with cardiac left-ventricle (LV) dysfunction, using 2D-STE software widely used in postnatal echocardiography. A prospective longitudinal cohort study was performed, and global (GLO) and segmental LV longitudinal strain was measured offline and compared between FGR and appropriate-for-gestational-age (AGA) fetuses throughout gestation. All cases of FGR fetuses were paired 1:2 to AGA fetuses, and linear mixed model analysis was performed to compare behavior differences between groups throughout pregnancy. Our study shows LV fetal longitudinal strain in FGR and AGA fetuses differed upon diagnosis and behaved differently throughout gestation. FGR fetuses had lower LV strain values, both global and segmental, in comparison to AGA, suggesting subclinical cardiac dysfunction. Our study provides more data regarding fetal cardiac function in cases of placental dysfunction, as well as highlights the potential use of 2D-STE in the follow-up of cardiac function in these fetuses.

Speckle Tracking Analysis in Fetuses with D-Transposition: Predicting the Need for Urgent Neonatal Balloon Atrial Septostomy

INTRODUCTION

Speckle tracking analysis of the endocardium of the right (RV) and left (LV) ventricles was used to evaluate the size, shape, and contractility of these chambers in fetuses with D-Transposition of the great arteries (D-TGA) to identify fetuses that would require emergent balloon atrial septostomy (BAS) after birth.

METHODS

This was a retrospective analysis of fetuses with D-TGA and intact ventricular septum that were divided into 2 groups. Group 1 underwent urgent BAS after birth because of a restrictive atrial septum and group 2 did not. Using speckle tracking analysis, the end-diastolic and end-systolic RV and LV areas, lengths, widths, sphericity indices, and contractility were computed. Logistic regression analysis was performed to identify fetuses who would require urgent neonatal BAS.

RESULTS

Of the 39 fetuses with D-TGA, 55% (n = 22) required urgent neonatal BAS (group 1) and 45% (n = 17) (group 2) did not. When comparing D-TGA groups 1 and 2, differences were seen in RV and LV area, sphericity index for segment 1 of the LV, LV fractional area of change and free wall annular plane systolic excursion, fractional shortening for LV segment 12, and RV free wall strain. Regression analysis of these measurements identified 91% of neonates who underwent BAS, with a false-positive rate of 12%.

CONCLUSION

Using speckle tracking analysis to evaluate the RV and LV, measurable differences were identified for the RV and LV size, shape, and contractility between fetuses who underwent neonatal urgent BAS vs. those who did not require this procedure.

Assessing maternal cardiac function by obstetricians: technique and reference ranges

BACKGROUND

A strong body of evidence has now coalesced indicating that some obstetrical syndromes may result from maladaptive responses of the maternal cardiovascular system. Longitudinal studies have shown that these changes are complex and present before the clinical recognition of preeclampsia and fetal growth restriction, suggesting that hemodynamic maladaptation may play an etiologic role in obstetrical complications. Chronic hypertension is one of the most frequent complications of pregnancy, and recent evidence suggests that control of mild hypertension in early pregnancy improves outcome. The management of chronic hypertension can be improved by understanding specific cardiovascular hemodynamic abnormalities such as increased cardiac output or increased systemic vascular resistance, which can respond to either beta or calcium channel blockers, depending on the hemodynamic findings. Evaluation of maternal cardiac function has not been previously available to obstetrical healthcare providers using diagnostic ultrasound equipment used for fetal evaluation.

OBJECTIVE

Obstetrical ultrasound machines may be configured for various probes (endovaginal, abdominal, 3D/4D, and cardiac). This study used a cardiac probe placed in the suprasternal notch to image and measure the descending aorta diameter and the velocity time integral using pulsed and continuous wave Doppler ultrasound in normal pregnant women between 11 and 39 weeks of gestation. These measurements were followed by computation of maternal left ventricular preload, afterload, contractility, and blood flow.

STUDY DESIGN

This was a prospective cross-sectional study. A total of 400 pregnant women were recruited between 11 and 39 weeks of gestation. Imaging of the maternal aortic arch was performed by placing a cardiac probe in the suprasternal notch to identify the aortic arch using 2D and color Doppler ultrasound. The end-systolic diameter of the aorta was measured at the junction of the left subclavian artery with the descending aorta, which was followed by insonation of the descending aorta to obtain the Doppler waveform. Following insonation of the descending aorta, measurements of the aortic diameter, velocity time integral, ejection time, mean pressure gradient, heart rate, maternal weight and height, and systolic and diastolic blood pressures were entered into an Excel spreadsheet to compute the following: (1) preload measurements of stroke volume, stroke volume index, and stroke work index; (2) afterload measurements of systemic vascular resistance and the potential-to-kinetic energy ratio; (3) contractility measurements of inotropy and the Smith-Madigan inotropy index; and (4) blood flow measurements of cardiac output and the cardiac output index. Fractional polynomial regression analysis was performed for each of the above measurements using gestational age as the independent variable.

RESULTS

The diastolic and mean arterial blood pressure decreased from 11 to 18 weeks of gestation and then increased until term. The afterload measurements demonstrated similar characteristics, as all values decreased from 11 weeks until the mid and late second trimester, after which all values increased until term. Changes in contractility demonstrated an increase from 11 weeks to 25 to 28 weeks, followed by a decline until term. Changes in blood flow demonstrated an increase from 11 to 27 weeks and then declined until term. The continuous wave Doppler values were greater than the pulsed Doppler values except for the contractility measurements. Examples of abnormal cardiac measurements were identified in pregnant patients with hypertension and fetal growth restriction. An Excel calculator was created to provide quick computation of z-score measurements and their corresponding centiles described in this study.

CONCLUSION

The technique for evaluation of maternal cardiac function described in this study would allow screening of maternal left ventricular preload, afterload, contractility, and blood flow in the obstetrical clinical milieu once a cardiac probe is acquired for obstetrical ultrasound machines used for fetal evaluation. The above measurements would allow the clinician to select appropriate hypertensive medication on the basis of the results of the evaluation of the maternal left ventricle.

Evaluation of changes of cardiac morphology and function in fetuses with ductus arteriosus constriction by Speckle-tracking echocardiography

BACKGROUND

Premature ductus arteriosus constriction (DA Con) can result in right ventricular enlargement, right ventricular hypertrophy, and tricuspid regurgitation.

METHOD

This study retrospectively analyzed 34 singleton fetuses that underwent fetal echocardiography with a diagnosis of DA Con (16 cases with mild to moderate, and 18 cases with moderate to severe) and 45 healthy fetuses. The morphology and function parameters of cardiac, as well as the 24-Segment of ventricles, were compared between the DA Con group and controls, and between the mild to moderate and moderate to severe groups, using the fetal heart quantification (FHQ) technology.

RESULTS

There were no significant difference in left ventricular parameters in DA Con group when compared to controls. Moreover, fetal 4CV-GSI was significantly reduced, as well as the sphericity index (SI), fractional shortening (FS), global longitudinal strain (GS) and fractional area change (FAC) of right ventricle, especially in the basal-middle segments. Compared with the mild to moderate group, LV-FS increased and RV-FS decreased in moderate to severe group.

CONCLUSION

The results showed that the fetal heart in the DA Con group was different from the controls in morphology and function. FHQ technology provides a comprehensive assessment for the evaluation of cardiac morphological and functional changes in DA Con fetuses.

Umbilical Venous Volume Flow in Late-Onset Fetal Growth Restriction

OBJECTIVES

Umbilical vein flow (UVF) is reduced in fetal growth restriction (FGR). We compared absolute and size-adjusted UVF (estimated fetal weight [EFW] and abdominal circumference [AC]) and rates of abnormal UVF parameters (<10th percentile) among FGR fetuses meeting Delphi criteria (FGR-D) against small for gestational age (SGA) fetuses and appropriate for gestational age (AGA) controls.

METHODS

Absolute UVF, UVF/EFW, and UVF/AC were compared between 73 FGR pregnancies (35 FGR-D, 38 SGA) and 108 AGA controls. Rates of abnormal UVF were compared to abnormal umbilical artery pulsatility index (UAPI). Independent samples t-tests, Mann-Whitney U, odds ratio (OR), chi-squared, and Fisher's exact tests were used as appropriate.

RESULTS

Mean absolute UVF was significantly decreased in FGR-D compared to AGA (P = .0147), but not between SGA and AGA fetuses. The incidence of both abnormal absolute UVF and UVF/AC values (<10th centile) was higher among late-onset FGR fetuses versus AGA fetuses (UVF: OR 2.7, confidence interval [CI] 1.37-5.4; UVF/AC: OR 2.73, CI 1.37-5.4). UVF was more frequently abnormal than UAPI and in only two fetuses were both Doppler values abnormal.

CONCLUSION

Absolute UVF is altered in late-onset FGR, and most pronounced among FGR-D. UVF may provide additional insight into fetal compromise in those affected by growth restriction.

Evaluation of Fetal Cardiac Function in Maternal Gestational Diabetes Mellitus by Speckle-Tracking Echocardiography

OBJECTIVES

Gestational diabetes mellitus (GDM) is the most common metabolic disease that occurs during pregnancy and may result in fetal cardiac dysfunction. Our study aimed to assess the cardiac function in fetuses of mothers with GDM by a quantitative analysis software based on speckle-tracking echocardiography.

METHODS

Forty-nine fetuses exposed to GDM and 50 normal fetuses were enrolled, and fetal echocardiography were performed and analyzed in this prospective cross-sectional study. We compared cardiac systolic function between the two groups using fetal cardiac quantitative analysis software.

RESULTS

In the GDM group, left ventricular (24 ± 4 versus 28 ± 4, P < .001) and right ventricular global longitudinal strain (23 ± 4 versus 26 ± 4, P = .002) and right ventricular free wall strain (26 ± 6 versus 29 ± 5, P = .006) were significantly lower compared with the control group, whereas there was no significant difference in global spherical index (1.2 ± 0.1 versus 1.2 ± 0.1, P = .425). Additionally, 24-segment transverse fraction shortening of the right ventricle was more impaired than the left, and the segments with reduced fraction shortening were mainly located in the mid and apical sections of the right ventricle, and midsection of the left ventricle.

CONCLUSION

Fetuses exposed to GDM may have cardiac dysfunction before the onset of cardiac morphologic abnormalities, and the right ventricle is more vulnerable than the left during fetal development.

Speckle-Tracking Analysis in Fetuses With Tetralogy of Fallot: Evaluation of Right and Left Ventricular Contractility and Left Ventricular Function

OBJECTIVES

This study examines fetuses with tetralogy of Fallot (TOF) and evaluates the right (RV) and left (LV) ventricular contractility and LV function using speckle-tracking analysis of the endocardium.

METHODS

The study group consisted of 44 fetuses with TOF, of which 34% had pulmonary valve atresia (N = 15) and 59% (N = 26) had pulmonary valve stenosis. The RV and LV global fractional area change, longitudinal contractility (longitudinal strain, free wall strain, septal strain, free wall and septal annular fractional shortening, and free wall and septal wall annular plane systolic excursion), and transverse contractility (24-segment fractional shortening) as well as LV functional assessment (stroke volume, cardiac output, and ejection fraction) were measured using speckle-tracking analysis. The z-scores of the measurements were compared to 200 controls.

RESULTS

Compared to controls, measurements of LV contractility in fetuses with TOF demonstrated significantly abnormal values for global contractility, longitudinal contractility, and transverse contractility of the mid and apical segments. LV function was abnormal for stroke volume (SV), cardiac output (CO), and ejection fraction (EF). In comparison, RV contractility demonstrated no significant difference between TOF and control z-score values for RV global contractility. Only two RV measurements were found to be abnormal: longitudinal contractility and transverse contractility of the apical segments.

CONCLUSION

Using multiple measurement tools to evaluate global, longitudinal, and transverse contractility, this study identified significant differences between fetuses with TOF and healthy controls, with greater contractility abnormalities seen in the LV than in the RV.

Cardiac Size, Shape, and Ventricular Contractility in Fetuses at Sea Level With an Estimated Weight Less-than 10th Centile

OBJECTIVES

To investigate cardiac size, shape, and ventricular contractility in fetuses with estimated fetal weight (EFW) <10th centile at sea level (Houston).

METHODS

A prospective ultrasound study examined 37 fetuses with EFW <10th centile at sea level. High-frequency cine clips were used to evaluate the 4-chamber view including end-diastolic measurements and global sphericity index. The size, shape, and contractility of both ventricles were analyzed with speckle tracking methods. Z scores were calculated using the mean ± standard deviation (SD) derived from normal controls. Measurements were abnormal if their Z score values were <-1.65 or >+1.65. The proportion of small fetuses with abnormal parameters was compared to normal reference ranges. Results were compared to a similar published study of small fetuses at higher altitude in Denver.

RESULTS

About one-third of Houston fetuses with EFW <10th centile had enlarged globular shaped 4-chamber hearts with increased right ventricle (RV) area, RV basal-apical length, RV base width, and left ventricle (LV) basal-apical length measurements. Bilateral ventricular hypertrophy was often present. An increased proportion of Houston fetuses had increased ventricular contractility. However, decreased ventricular contractility was more prevalent for higher altitude fetuses.

CONCLUSIONS

Third trimester fetuses at sea level, with an EFW <10th centile, were often associated with enlarged and globular-shaped hearts. They had increased global and longitudinal ventricular contractility as compared to controls. Higher altitude fetuses also had enlarged globular-shaped hearts but with a greater proportion of cases having decreased ventricular contractility as compared to the sea level cohort.

Patterns of Brain Sparing in a Fetal Growth Restriction Cohort

Objective: Our objective was to compare differences in Doppler blood flow in four fetal intracranial blood vessels in fetuses with late-onset fetal growth restriction (FGR) vs. those with small for gestational age (SGA). Methods: Fetuses with estimated fetal weight (EFW) <10th percentile were divided into SGA (n = 30) and FGR (n = 51) via Delphi criteria and had Doppler waveforms obtained from the middle cerebral artery (MCA), anterior cerebral artery (ACA), posterior cerebral artery (PCA), and vertebral artery (VA). A pulsatility index (PI) <5th centile was considered “abnormal”. Outcomes included birth metrics and neonatal intensive care unit (NICU) admission. Results: There were more abnormal cerebral vessel PIs in the FGR group versus the SGA group (36 vs. 4; p = 0.055). In FGR, ACA + MCA vessel abnormalities outnumbered PCA + VA abnormalities. All 8 fetuses with abnormal VA PIs had at least one other abnormal vessel. Fetuses with abnormal VA PIs had lower BW (1712 vs. 2500 g; p < 0.0001), delivered earlier (35.22 vs. 37.89 wks; p = 0.0052), and had more admissions to the NICU (71.43% vs. 24.44%; p = 0.023). Conclusions: There were more anterior vessels showing vasodilation than posterior vessels, but when the VA was abnormal, the fetuses were more severely affected clinically than those showing normal VA PIs.

Cardiac Function Assessment in Fetuses With Ductus Arteriosus Constriction: A Two-Dimensional Echocardiography and FetalHQ Study

Background

Fetal ductal constriction (DC) is associated with excessive polyphenol-rich food (PRF) consumption during pregnancy. However, the effect of this hemodynamic change on fetal cardiac function still needs to be elucidated. Therefore, this study aimed to evaluate the cardiac function of fetuses with PRF-related DC and to describe serial observations of cardiac function changes.

Methods

We compared the traditional echocardiographic indices, including morphological, hemodynamic, and functional parameters, between study fetuses and controls. For global and segmental deformation analysis of the left and right ventricles, fetalHQ with the speckle-tracking technique was used to calculate sphericity index (SI), global longitudinal strain (GLS), fractional shortening (FS), fractional area change (FAC), etc. In addition, follow-up data were compared with the generalized linear model.

Results

A total of 60 DC fetuses and 60 gestational-matched controls were enrolled in our study, with 20 DC fetuses undertaking a follow-up echocardiogram after 2–3 weeks. Compared with controls, there was a distinct decrease in right ventricular GLS (RVGLS) (−13.39 ± 3.77 vs. −21.59 ± 2.51, p &lt; 0.001), RVFAC (22.20 ± 9.56 vs. 36.01 ± 4.84, p &lt; 0.001), left ventricular GLS (LVGLS) (−19.52 ± 3.24 vs. −23.81 ± 2.01 p &lt; 0.001), and LVFAC (39.64 ± 7.32 vs. 44.89 ± 4.91, p = 0.004). For 24-segment FS analysis, DC fetuses showed lower FS in left ventricular (LV) segments 18–24, with no difference in LV segments 1–17. Right ventricular (RV) FS in segments 4–23 was also reduced in the DC group. The 24-segment SI analysis indicated significantly lower SI in DC than those in controls for LV segments 1–14 and RV segments 19–24. We found that the pulsatility index (PI) of ductus arteriosus (DA) was an independent variable for RVGLS (β = −0.29, p = 0.04). In 20 DC fetuses with follow-up echocardiograms, no obvious difference in myocardial deformation was found between the initial examination and follow-up data.

Conclusion

Left and right ventricular performances were both impaired in DC fetuses, along with a series of morphological and hemodynamic changes. Although the state of DA constriction improved on second examinations, cardiac function was not completely restored.

3D Fractional Limb Volume Identifies Reduced Subcutaneous and Lean Mass in Fetal Growth Restriction

OBJECTIVES

Fetal 2D and 3D fractional limb volume (FLV) measurements by ultrasound can detect fetal lean and subcutaneous mass and possibly percent body fat. Our objectives were to 1) compare FLV measurements in fetuses with fetal growth restriction (FGR) versus small for gestational age (SGA) defined by the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG)-supported international Delphi consensus and 2) correlate FLV findings with birth metrics. We hypothesize that FLV measurements will be significantly smaller in FGR versus SGA fetuses and will correlate closer with Ponderal index (PIx) in the neonate than abdominal circumference (AC).

METHODS

Patients were categorized as FGR or SGA as defined by ISUOG. Total thigh volume (TTV), volumes of lean mass (LMV), and fat mass volume (FMV) were calculated from 3D acquisitions. Measurements were compared between groups and correlated with birthweight (BW) and PIx (BW/crown-heal length).

RESULTS

The FGR group (n = 37) delivered earlier (37/2 versus 38/0; P = .0847), were lighter (2.2 kg versus 2.6 kg; P = .0003) and had lower PIx (0.023 versus 0.025; P = .0013) than SGAs (n = 22). FGRs had reduced TTV (40.6 versus 48.4 cm³ ; P = .0164), FMV (20.8 versus 25.3 cm³ ; P = .0413), and LMV (19.8 versus 23.1 cm³ ; P = .0387). AC had the highest area under the curve (0.69) for FGR. FMV was more strongly associated with PIx than the AC (P = .0032).

CONCLUSIONS

The AC and FLV measurements were significantly reduced in FGR fetuses compared to SGAs. While the AC outperformed FLV in predicting FGR, the FLV correlated best with PIx, which holds investigative promise.

Doppler velocimetry discordance between paired umbilical artery vessels and clinical implications in fetal growth restriction

BACKGROUND

Studies revealing a discrepancy in umbilical artery Dopplers between the two umbilical arteries in normally-grown fetuses necessitates further evaluation of the paired umbilical arteries in the setting of fetal growth restriction as this is a critical component in the surveillance of this population.

OBJECTIVE

Umbilical artery Doppler sampling in fetal growth restriction is typically assessed in 1 umbilical artery in a free loop of cord. Although discrepancies of >20% between the 2 umbilical arteries occur in 1 of 3 normal pregnancies, this has not been assessed in fetal growth restriction. Our objectives were to determine the frequency of discordant Doppler pulsatility indices between paired umbilical arteries in a fetal growth restriction cohort and to determine if sampling of 1 or both arteries alters surveillance or timing of delivery.

STUDY DESIGN

A cohort of 425 growth-restricted fetuses between 25 and 39 weeks of gestation had umbilical artery Doppler pulsatility indices determined from both umbilical arteries in a midsegment of the cord to determine: (1) the discrepancy percentage between paired umbilical artery pulsatility indices and (2) the frequency of both arteries being normal, abnormal, or discordant (pulsatility index < and >95th percentile). To determine what sampling method increased the detection of an abnormal Doppler index, 3 sampling methods were compared: (1) average pulsatility index from both umbilical arteries, (2) pulsatility index from 1 umbilical artery chosen randomly, and (3) highest pulsatility index of the 2 umbilical arteries.

RESULTS

The mean percentage difference between umbilical artery pulsatility indices was 11.7%, and in 15.8% of cases, it exceeded 20%. Both umbilical artery pulsatility indices were normal in 71.1% (302/425), abnormal in 12.2% (52/425), and discordant in 16.7% (71/425) of cases (P<.0001). Of the 3 sampling methods, the pulsatility index was abnormal in: (1) 19.2% (82/425) of cases when averaged from both umbilical arteries, (2) 22.1% (94/425) of cases when choosing 1 umbilical artery at random, and (3) 28.9% (123/425) of cases when the highest umbilical artery pulsatility index was used (P=.003).

CONCLUSION

In this large fetal growth restriction cohort, the overall discrepancy between the 2 umbilical artery pulsatility indices was 11.7%. Among fetuses with at least 1 abnormal umbilical artery pulsatility index, 71 of 123 (57.7%) had 1 normal pulsatility index and 1 abnormal. Thus, the number of arteries sampled and the sampling method used may alter clinical decision-making, including frequency of surveillance and timing of delivery.

Feasibility of 4D-Spatio Temporal Image Correlation (STIC) in the Comprehensive Assessment of the Fetal Heart Using FetalHQ®

Fetal Heart Quantification (FetalHQ®) is a novel speckle tracking software that permits the study of global and regional ventricular shape and function from a 2D four-chamber-view loop. The 4D-Spatio Temporal Image Correlation (STIC) modality enables the offline analysis of optimized and perfectly aligned cardiac planes. We aimed to evaluate the feasibility and reproducibility of 4D-STIC speckle tracking echocardiography (STE) using FetalHQ® and to compare it to 2D STE. We conducted a prospective study including 31 low-risk singleton pregnancies between 20 and 40 weeks of gestation. Four-chamber view volumes and 2D clips were acquired with an apex pointing at 45° and with a frame rate higher than 60 Hz. Morphometric and functional echocardiography was performed by FetalHQ®. Intra- and interobserver reproducibility were evaluated by the intraclass correlation coefficient (ICC). Our results showed excellent reproducibility (ICC > 0.900) for morphometric evaluation (biventricular area, longitudinal and transverse diameters). Reproducibility was also good (ICC > 0.800) for functional evaluation (biventricular strain, Fractional Area Change, left ventricle volumes, ejection fraction and cardiac output). On the contrary, the study of the sphericity index and shortening fraction of the different ventricular segments showed lower reproducibility (ICC < 0.800). To conclude, 4D-STIC is feasible, reproducible and comparable to 2D echocardiography for the assessment of cardiac morphometry and function.

Assessment of the Size and Shape of the 4-Chamber View and the Right and Left Ventricles using Fetal Speckle Tracking in Normal Fetuses at 17-24 Gestational Weeks

INTRODUCTION

The aim of the study was to establish normal reference values obtained by fetal speckle tracking analysis of the fetal heart between 17-24 weeks of gestation among Thai fetuses and compare the nomograms with previous studies.

METHODS

The 4-chamber view of the fetal heart in 79 normal fetuses was analyzed by speckle tracking analysis to determine the best-fit regression model. The 95% reference intervals and Z-score equations of fetal cardiac parameters were computed.

RESULTS

The end-diastolic length, width, area, and circumference of the 4-chamber view (4CV) as well as the ventricular end-diastolic length, 24-segment widths, and area were all increased as a function of gestational age (GA) and 5 fetal biometric parameters. In contrast, the global sphericity index (SI), 24-segment SI, and right ventricle/left ventricle width and area ratios did not change with GA or fetal biometric measurements. There were few differences in Z-score reference ranges of fetal cardiac measurements between the current study and previous studies conducted in different patient populations.

CONCLUSION

Our study provided z-score and corresponding centile calculators, 5th and 95th centile reference tables, and corresponding graphs for evaluating the size and shape of the 4CV and the right and left ventricles using 6 independent variables between 17 and 24 weeks of gestation. These results provide normal reference ranges for future studies of fetuses with pathologies that may alter the size and shape of the 4-chamber view and ventricles.

Fetal-TAPSE for Surveillance of Cardiac Function in Growth-Restricted Fetuses With a Portosystemic Shunt

OBJECTIVES

Congenital portosystemic shunt (CPSS) in a growth-restricted fetus may lead to cardiac overload and ultimately hemodynamic imbalance. The aim of the study was to describe the application of tricuspid annular plane systolic excursion (TAPSE) for surveillance of cardiac function in growth-restricted fetuses diagnosed with CPSS.

METHODS

The study group consisted of 7 fetuses with growth restriction diagnosed with CPSS between 2018 and 2020. Patients were followed longitudinally every 2 weeks. Sonographic fetal-TAPSE (f-TAPSE) was performed every 2 weeks. At each visit, the following parameters were recorded: estimated fetal weight, biophysical profile, nonstress test, Doppler flow indices, and fetal cardiothoracic index. Postnatal laboratory and imaging tests were retrieved from the medical files.

RESULTS

Mean gestational age at diagnosis of CPSS was 32 + 1 weeks. Cardiomegaly was observed in all cases. All portosystemic shunts were classified as intrahepatic. Values of f-TAPSE were above the 95th percentile in 6/7 fetuses at presentation and throughout follow-up. Gestational age at delivery ranged between 36 + 5 and 38 + 5 weeks. Postnatally, spontaneous closure of the shunt was noted in 2 infants. Transient hyperammonemia was diagnosed in 2 neonates, with no signs of the characteristic complication.

CONCLUSIONS

In growth-restricted fetuses diagnosed concomitantly with CPSS, f-TAPSE offers a practical sonographic tool for assessment of cardiac function and may serve as an additional clinical marker for follow-up. The appearance of cardiomegaly in growth-restricted fetuses should prompt a dedicated sonographic evaluation of the fetal portal system.

Fetal cardiac geometry and function in pregnancies with well-controlled gestational diabetes mellitus using Fetal HQ

OBJECTIVE

To determine whether abnormal cardiac shape and ventricular global, transverse, and longitudinal contractility are present in fetuses of women with well-controlled GDM.

METHODS

A prospective observational study was performed on 80 fetuses of women with well-controlled GDM and 90 control fetuses. Using Fetal HQ, a new speckle-tracking technique, cardiac shape, global contractility, transverse contractility, and longitudinal contractility were calculated. The number and percentage of fetuses with z score values below 5th or above 95th were computed.

RESULTS

Compared with controls, there were no significant differences in the frequency of cardiac geometric abnormalities in GDM fetuses. Despite good glycemic control, 60.0% of fetuses in the well-controlled GDM group had one or more types of global, longitudinal, and transverse contractility abnormalities of one or both ventricles, but more frequent on the right ventricle (RV, 50%). The most frequent abnormality of the RV occurred in the transverse contractility (35%), followed by abnormalities of global contractility (25%), and longitudinal contractility (21.3%), compared with controls. The left ventricle (LV) analysis demonstrated that the percentage of study fetuses with only transverse contractility abnormality (18.8%) was significantly higher.

CONCLUSIONS

Despite good glycemic control, abnormal ventricular contractility was present in fetuses of women with GDM, but more frequent in the RV. For both the RV and LV, transverse ventricular contractility abnormality were more prevalent than abnormal global and longitudinal contractility. Fetuses of women with GDM should be evaluated for ventricular contractility abnormality and have more follow-ups despite good glycemic control.

Comparing the Non-Quiver and Quiver Techniques for Identification of the Endocardial Borders Used for Speckle-Tracking Analysis of the Ventricles of the Fetal Heart

This study compared the non-quiver with the quiver technique for identifying the end-systolic and end-diastolic endocardium of the fetal right ventricle (RV) and left ventricle (LV) used for speckle-tracking analysis. Bland-Altman and t test analyses showed no significant differences in measurements between the techniques for the RV and LV. The difference in the time required to perform the non-quiver analysis was significantly longer (P < .001) for the RV and LV than the quiver technique. The quiver technique allows the examiner to efficiently identify the endocardial borders of the fetal heart compared with the non-quiver method.

A 24-segment fractional shortening of the fetal heart using FetalHQ

OBJECTIVES

To evaluate 24-segment fractional shortening (FS) of the fetal heart using FetalHQ by speckle-tracking regarding reproducibility and the change with advancing gestation.

METHODS

Eighty-one pregnant women at 18-21+6 and 28-31+6 weeks of gestation were studied using FetalHQ with the speckle-tracking technique to calculate 24-segment FS of left and right ventricles. Intra- and inter-class correlation coefficients and intra- and inter-observer agreements of measurements for FS were assessed in each segment.

RESULTS

With respect to intra-observer reproducibility, all FS values showed correlations between 0.575 and 0.862 for the left ventricle, with good intra-observer agreements except for left ventricular segments 14-24. Right ventricular FS values showed correlations between 0.334 and 0.685, with good intra-observer agreements. With respect to inter-observer reproducibility, all FS values showed correlations between 0.491 and 0.801 for the left ventricle, with good intra-observer agreements except for left ventricular segments 16-22. Right ventricular FS values showed correlations between 0.375 and 0.575, with good inter-observer agreements. There were significant differences in the mean FS values in the basal segment (segments 1-5) of the left ventricle between 18 and 21+6 and 28-31+6 weeks of gestation (p<0.05), whereas there were significant differences in all mean FS values in the right ventricle between both gestational ages (p<0.05).

CONCLUSIONS

These results suggest that the reproducibility of the 24-segment FS of the fetal heart using FetalHQ is fair. However, there may be significant differences in FS values with advancing gestational age, especially for the right ventricle.

Echocardiographic assessment of fetal cardiac function in the uterine artery ligation rat model of IUGR

BACKGROUND

Intrauterine growth restriction (IUGR) leads to cardiac dysfunction and adverse remodeling of the fetal heart, as well as a higher risk of postnatal cardiovascular diseases. The rat model of IUGR, via uterine artery ligation, is a popular model but its cardiac sequelae is not well investigated. Here, we performed an echocardiographic evaluation of its cardiac function to determine how well it can represent the disease in humans.

METHODS

Unilateral uterine artery ligation was performed at embryonic day 17 (E17) and echocardiography was performed at E19 and E20.

RESULTS

Growth-restricted fetuses were significantly smaller and lighter, and had an higher placenta-to-fetus weight ratio. Growth-restricted fetal hearts had reduced wall thickness-to-diameter ratio, indicating left ventricular (LV) dilatation, and they had elevated trans-mitral and trans-tricuspid E/A ratios and reduced left and right ventricular fractional shortening (FS), suggesting systolic and diastolic dysfunction. These were similar to human IUGR fetuses. However, growth-restricted rat fetuses did not demonstrate head-sparing effect, displayed a lower LV myocardial performance index, and ventricular outflow velocities were not significantly reduced, which were dissimilar to human IUGR fetuses.

CONCLUSIONS

Despite the differences, our results suggest that this IUGR model has significant cardiac dysfunction, and could be a suitable model for studying IUGR cardiovascular physiology.

IMPACT

Animal models of IUGR are useful, but their fetal cardiac function is not well studied, and it is unclear if they can represent human IUGR fetuses. We performed an echocardiographic assessment of the heart function of a fetal rat model of IUGR, created via maternal uterine artery ligation. Similar to humans, the model displayed LV dilatation, elevated E/A ratios, and reduced FS. Different from humans, the model displayed reduced MPI, and no significant outflow velocity reduction. Despite differences with humans, this rat model still displayed cardiac dysfunction and is suitable for studying IUGR cardiovascular physiology.

Two-dimensional Speckle tracking echocardiography in Fetal Growth Restriction: a systematic review

Background Fetal growth restriction (FGR), defined as an estimated fetal weight (EFW)<10th percentile, is associated with an increased risk for adverse fetal and neonatal outcome. Early antenatal diagnosis is important and remains challenging. Deformation changes in the fetal myocardium are early signs of myocardial dysfunction. These changes can be measured using two-dimensional speckle tracking echocardiography (2D-STE) to predict impaired placental function in the growth restricted fetus. Aim To review the literature on fetal heart deformation values measured with 2D-STE, in fetuses with an EFW< 10th centile and appropriate for gestational age (AGA) fetuses, and to compare the results in both groups. Methods The EMBASE, Medline, and Cochrane databases were searched from inception until April 2020. Observational studies on evaluating the cardiac deformation values longitudinal strain, strain rate, and/or global dyssynchrony of both ventricles in FGR, using 2D-STE, were included. Methodological quality was assessed using the Newcastle-Ottowa risk of bias scale. Results Four studies met the inclusion criteria. The mean gestational age (GA) varied from 30 to 38 weeks in the FGR group and 20 to 40 weeks in AGA fetuses. The number of included FGR fetuses (with or without Doppler abnormalities), varied from 30 to 50. Longitudinal strain in FGR fetuses was described as comparable (n = 2), increased (n = 1) and>95th percentile (n = 1) compared to AGA fetuses. Strain rate was measured in two studies. One reported an increased strain rate, another showed comparable strain rate. Two studies addressed global left ventricle (LV) and right ventricle (RV) dyssynchrony. Dyssynchrony was increased in FGR compared to AGA fetuses. Conclusion The currently published data is limited and heterogeneous concerning GA and Doppler profiles. The data presentation and the interpretation thereof make qualitative comparisons impossible. Large prospective longitudinal cohort studies looking at the value of deformation measurements of the fetal heart in FGR and AGA fetuses are needed to assess the clinical significance of deformation values measured with 2D-STE.

Right ventricular dysfunction identified by abnormal strain values precedes evident growth restriction in small for gestational age fetuses

OBJECTIVES

Small for gestational age (SGA) fetuses have an increased risk for adverse outcome. Placental insufficiency leads to changes in the circulation, with secondary adaptation of the fetal heart resulting in changed cardiac deformation. This deformation can be measured with 2D speckle tracking echocardiography (2D-STE). SGA is antenatally often undiagnosed. The measurement of deformation changes in the fetal heart might help in the prediction of SGA and identify fetuses in need of more intensive surveillance.

METHODS

In this longitudinal prospective cohort study, global longitudinal strain (GLS) and strain rate (GLSR), measured before 23 weeks gestational age were compared between SGA and appropriate for gestational age (AGA) fetuses, based on birthweight corrected for gestational age at birth.

RESULTS

The fetal heart rate was significantly increased in SGA; 158 beats per minute (146-163) vs 148 (134-156); P = 0.035 in AGA. Right ventricle GLS (RV-GLS) values were significantly increased in SGA; -15.87% (-11.69% to -20.55%) vs -20.24% (-16.29% to -24.28%); p = 0.024, respectively.

CONCLUSION

RV-GLS values, measured with 2D-STE, were significantly increased in SGA, indicating systolic RV dysfunction before 23 weeks gestational age in fetuses who will become SGA later in pregnancy. A large longitudinal prospective cohort study is needed to confirm these findings.

Size and shape of the four-chamber view of the fetal heart in fetuses with an estimated fetal weight less than the tenth centile

BACKGROUND

Fetuses with an estimated fetal weight below the 10^th centile have an increased risk of adverse perinatal and long-term outcomes as well as increased rates of cardiac dysfunction, which often alters cardiac size and shape of the 4-chamber view and the individual ventricles. As a result, a simple method has emerged to screen for potential cardiac dysfunction in fetuses with estimated fetal weights <10^th centile by measuring the size and shape of the 4-chamber view and the size of the ventricles.

OBJECTIVE

To determine the number of fetuses with an abnormal size and shape of the 4-chamber view and size of the ventricles in fetuses with an estimated fetal weight <10^th centile.

MATERIALS AND METHODS

This was a retrospective study of 50 fetuses between 25 and 37 weeks of gestation with an estimated fetal weight <10^th centile. Data from their last examination were analyzed. From an end-diastolic image of the 4-chamber view, the largest basal-apical length and transverse width were measured from their corresponding epicardial borders. This allowed the 4-chamber view area and global sphericity index (4-chamber view length/4-chamber view width) to be computed. In addition, tracing along the endocardial borders with speckle tracking software enabled measurements of the right and left ventricular chamber areas and the right ventricle/left ventricle area ratios to be computed. Doppler waveform pulsatility indices from the umbilical (umbilical artery pulsatility index) and middle cerebral arteries (middle cerebral artery pulsatility index) were analyzed, and the cerebroplacental ratio (middle cerebral artery pulsatility index/umbilical artery pulsatility index) computed. Umbilical artery pulsatility indices >90^th and cerebroplacental ratios <10^th centile were considered abnormal. Using data from the control fetuses, the centile for each of the cardiac measurements was categorized by whether it was <10^th or >90^th centile, depending upon the measurement.

RESULTS

Of the 50 fetuses with estimated fetal weight <10^th centile, 50% (n = 25) had a normal umbilical artery pulsatility index and cerebroplacental ratio. These fetuses had significantly more (P < 0.02 to <0.0001) abnormalities of the size and shape of the 4-chamber view than controls. In all, 44% had a 4-chamber view area >90^th centile, 32% had a 4-chamber view global sphericity index <10^th centile, 56% had a 4-chamber view width >90^th centile, and 80% had 1 or more abnormalities of size and/or shape. The remaining 50% of fetuses (n = 25) had abnormalities of 1 or both for the umbilical artery pulsatility index and/or cerebroplacental ratio. These fetuses had significantly higher rates of abnormalities (P <0.05 to <0.0001) than controls for the following 4-chamber view measurements: 36% had a 4-chamber view area >90^th centile; 28% had a 4-chamber view global sphericity index <10^th centile; and 68% had a 4-chamber view width >90^th centile. Only those fetuses with an abnormal umbilical artery pulsatility index had significant changes in ventricular size; 56% had a left ventricular area <10^th centile; 28% had a right ventricular area <10^th centile; 36% had right ventricular/left ventricular area ratio >90^th centile. One or more of the above abnormal measurements were present in 92% of the fetuses.

CONCLUSION

Higher rates of abnormalities of cardiac size and shape of the 4-chamber view were found in fetuses with an estimated fetal weight <10^th centile, regardless of their umbilical artery pulsatility index and cerebroplacental ratio measurements. Those with a normal umbilical artery pulsatility index and an abnormal cerebroplacental ratio had larger and wider measurements of the 4-chamber view. In addition, the shape of the 4-chamber view was more globular or round than in controls. These fetuses may have an increased risk of perinatal complications and childhood and/or adult cardiovascular disease. Screening tools derived from the 4-chamber view, acting as surrogates for ventricular dysfunction, may identify fetuses who could benefit from further comprehensive testing and future preventive interventions.