Evaluating fetal tricuspid and mitral annular plane systolic excursion (TAPSE and MAPSE) using spatiotemporal image correlation (STIC) M-mode.

OBJECTIVES: This study aimed to evaluate the feasibility and reliability of tricuspid and mitral annular plane systolic excursion measurements (TAPSE and MAPSE) applying M-mode Spatiotemporal Image Correlation (STIC) technology in low-risk pregnancies. METHODS: An initial retrospective pilot study was carried out to assess repeatability, followed by a larger mixed cross-sectional and prospective longitudinal study, both evaluating low-risk singleton pregnancies between 22+6 and 39+1 weeks. As only annuli capture was necessary, STIC acquisition parameters were set to the minimum volume angle of 15° and acquisition time of 7.5 s. RESULTS: A total of 330 volumes were analysed offline applying STIC M-mode. Acquisition rates were 96.9 % for TAPSE and 93.7 % MAPSE in the pilot study (n=32) and 98.0 % for both in the longitudinal study (n=102). Both study designs revealed good repeatability for both sides of the heart, with higher intraclass correlation coefficients (ICCs) for TAPSE (0.84-0.94) compared to MAPSE (0.80-0.88). Good repeatability was demonstrated for both sides of the heart, more so for TAPSE than MAPSE, with ICCs for TAPSE 0.84-0.91 and MAPSE 0.75-0.76, comparable to prior ICCs for STIC repeatability. CONCLUSIONS: Modified STIC acquisition settings specifically tailored for capturing the longitudinal annular displacement may improve STIC TAPSE and MAPSE acquisition rates, optimising image quality for precise measurement and potentially bringing these modalities closer to clinical application.

Poor Correlation between Fetal Tissue Doppler Imaging and Pulsed Wave Myocardial Performance Indices.

INTRODUCTION: Both tissue Doppler imaging (TDI) and pulsed wave Doppler (PWD) Myocardial Performance Indices (MPIs) have been proposed as tools for functional fetal cardiology. We wished to determine if there was any correlation between TDI-MPI and PWD-MPI. METHODS: A cohort of uncomplicated women with morphologically normal singleton fetuses between 22 and 39 weeks of gestation was recruited. A single sonologist acquired Doppler waveforms for evaluation of both left and right TDI-MPI and PWD-MPI. The PWD-MPI values were calculated using a previously published algorithm and the TDI-MPI time intervals were measured manually by a single operator. RESULTS: Achievability and repeatability were high for both modalities. TDI produced significantly lower right MPI values yet significantly higher left MPI values, potentially reflecting their evaluation of physiologically different events, blood flow versus myocardial contraction. CONCLUSION: This study demonstrates that MPIs measured from PWD and TDI have a weak correlation and cannot be used interchangeably, even with the exclusion of suboptimal TDI-MPI scans from the analysis. Given the lack of correlation between the two methods, the high variation in TDI waveform, and the lack of unified approach to TDI analysis, we feel further research is needed before adoption of this technique.

Fetal and neonatal brain injury in twins complicated by twin anemia polycythemia sequence.

OBJECTIVES: To determine the rate of fetal and neonatal brain lesions and define risk factors for such lesions in pregnancies complicated by Twin Anemia Polycythemia Sequence (TAPS). METHODS: A retrospective cohort study of monochorionic twin pregnancies which were diagnosed with TAPS in a single tertiary medical center between 2013 and 2021. Pregnancies were followed with fetal brain neurosonogram every 2 weeks and fetal brain MRI (magnetic resonance imaging) was performed when indicated at 28-32 weeks of gestation; post-natal brain imaging included neonatal brain ultrasound. Pregnancies with pre- and post-natal brain lesions were compared to those without such findings. RESULTS: Overall, 23 monochorionic diamniotic pregnancies were diagnosed with TAPS over the study period resulting in perinatal survival of 91.3% (42/46). In 6/23 (26%) pregnancies and 7/46 (15.2%) fetuses pre- or post-natal brain lesions were detected, of whom five were the polycythemic twins and two were the anemic twins. Brain findings included intra-cerebral hemorrhage and ischemic lesions and were diagnosed prenatally in 6/7 (85.7%) cases. No risk factors for severe brain lesions were identified. CONCLUSIONS: TAPS may place the fetuses and neonates at increased risk for cerebral injuries. Incorporation of fetal brain imaging protocols may enhance precise prenatal diagnosis and allow for accurate parental counseling and post-natal care.

Fetal and neonatal brain lesions following laser ablation for twin-to-twin-transfusion-syndrome as detected by pre- and post-natal brain imaging.

OBJECTIVE: To determine the rate of and risk factors for fetal and neonatal brain lesions following laser ablation for twin-to-twin transfusion syndrome (TTTS). METHODS: A retrospective cohort study of 83 women with monochorionic twin pregnancies who underwent ablation for TTTS at a single tertiary hospital. Post-laser survivors were followed-up with fetal neurosonogram every 2 weeks and fetal brain MRI at 28-32 weeks of gestation; post-natal brain imaging included neurosonogram. Cases with pre- and post-natal brain lesions were compared to those without. RESULTS: 153 fetuses survived the immediate post-laser period and underwent brain imaging. Of these, 17 (11.11%) exhibited brain lesions on prenatal imaging studies, and 36 (32.4%) on post-natal ultrasound. Later gestational age (GA) at the time of ablation (23.0 vs. 21.4 weeks, p = 0.0244), post-laser twin-anemia-polycythemia-sequence (TAPS) (29.41% vs. 9.56%, p = 0.035) and birthweight discordancy (30% vs. 9%, p = 0.0025) were associated with prenatal brain lesions. Earlier GA at delivery (31.0 weeks vs. 32.2, p = 0.0002) and post-laser TAPS (25% vs. 9.33%, p = 0.038) were associated with post-natal brain lesions. CONCLUSIONS: Survivors of ablation for TTTS are at risk for brain lesions, which can be detected prenatally. Incorporation of neurosonogram and fetal brain MRI into the routine surveillance of such pregnancies should be considered.

Automation of the Fetal Right Myocardial Performance Index to Optimise Repeatability.

OBJECTIVES: To compare the repeatability and degree of absolute agreement of an automated fetal right myocardial performance index (MPI) algorithm with manual measurements along with the impact of MPI observer experience on these two aspects. METHODS: Prospective cross-sectional study of 65 uncomplicated singleton pregnancies from 22 to 39 weeks' gestation. Image analysis of double-waveform right MPI measurements was conducted first with a MATLAB automated MPI software and then independently by an experienced and an inexperienced observer. Intraclass correlation coefficients (ICCs) and 95% confidence intervals (95% CI) were used to evaluate manual and automated intra- and interobserver repeatability. In addition, Bland-Altman plots were used to determine the degree of absolute agreement. RESULTS: Successful automation was performed on 63 cases (97%) showing repeatability ICCs of: 0.83 manual intraobserver; 0.77 manual interobserver; 1.00 automated. The degree of absolute agreement between manual and automated values was: inexperienced observer ICC 0.43 (95% CI 0.21-0.62); experienced observer ICC 0.76 (95% CI 0.63-0.85). CONCLUSION: Automation of right MPI demonstrates a superior reproducibility over manual measurements and reduces the experience required for successful analysis. This may lend a greater clinical applicability to MPI, and future studies to develop an automated universal reference range would be useful.

Evaluating Spatiotemporal Image Correlation Technology as a Tool for Training Nonexpert Sonographers to Perform Examinations of the Fetal Heart.

OBJECTIVES: We aimed to evaluate the use of spatiotemporal image correlation (STIC) as a tool for training nonexpert examiners to perform screening examinations of the fetal heart by acquiring and examining STIC volumes according to a standardized questionnaire based on the 5 transverse planes of the fetal heart. METHODS: We conducted a prospective study at 2 tertiary care centers. Two sonographers without formal training in fetal echocardiography received theoretical instruction on the 5 fetal echocardiographic transverse planes, as well as STIC technology. Only women with conditions allowing 4-dimensional STIC volume acquisitions (grayscale and Doppler) were included in the study. Acquired volumes were evaluated offline according to a standardized protocol that required the trainee to mark 30 specified structures on 5 required axial planes. Volumes were then reviewed by an expert examiner for quality of acquisition and correct identification of specified structures. RESULTS: Ninety-six of 112 pregnant women examined entered the study. Patients had singleton pregnancies between 20 and 32 weeks' gestation. After an initial learning curve of 20 examinations, trainees succeeded in identifying 97% to 98% of structures, with a highly significant degree of agreement with the expert's analysis (P < .001). A median of 2 STIC volumes for each examination was necessary for maximal structure identification. Acquisition quality scores were high (8.6-8.7 of a maximal score of 10) and were found to correlate with identification rates (P = .017). CONCLUSIONS: After an initial learning curve and under expert guidance, STIC is an excellent tool for trainees to master extended screening examinations of the fetal heart.

Congenital Cytomegalovirus Infection Following Second and Third Trimester Maternal Infection Is Associated With Mild Childhood Adverse Outcome Not Predicted by Prenatal Imaging.

BACKGROUND: While it is clear that first trimester congenital cytomegalovirus (CMV) infection can lead to serious neonatal and childhood adverse outcome, the extent of the effect of second and third trimester congenital CMV infection is still unclear. Our aim was to study the short- and long-term outcomes following second and third trimester infection and to evaluate the contribution of prenatal imaging in a prospective cohort. METHODS: We studied pregnant women with primary CMV infection in the second and third trimesters, as diagnosed by well-dated seroconversion, and proof of vertical CMV transmission. All patients underwent serial prenatal ultrasound (US) and most of them fetal magnetic resonance imaging (MRI). Follow-up information was obtained from hospital charts and by telephone interviews with parents. RESULTS: Primary CMV infection occurred in 135 patients, 107 and 28 with second and third trimester infection, respectively. The incidence proportion of composite outcome (hearing loss or neurodevelopmental impairment) following second trimester infection was 7% (7/100, after excluding cases that were terminated) with a 3% incidence of partial unilateral sensory neural hearing loss and a 5% incidence of minor neurodevelopmental abnormalities, including slight verbal and motor delay. Following third trimester infection, there was one case of a very mild motor delay. The incidence proportion of abnormal prenatal findings on US or MRI was not significantly correlated to hearing loss or neurodevelopmental abnormalities. CONCLUSIONS: Second trimester infection is associated with a slight risk of developing mild childhood sequelae, mostly partial unilateral hearing loss, which may develop late in childhood. Prenatal imaging failed to predict the development of childhood adverse outcome.