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Introduction: The purpose was to compare thymus size measured during second trimester screening of fetuses who were subsequently small for gestational age at birth (weight below 10th percentile, SGA group) with fetuses with normal birth weight (control group). We hypothesized that measuring the fetal thymic-thoracic ratio (TT-ratio) might help predict low birth weight. Methods: Using three-vessel view echocardiograms from our archives, we measured the anteroposterior thymus size and the intrathoracic mediastinal diameter to derive TT-ratios in the SGA (n = 105) and control groups (n = 533) between 19+0 and 21+6 weeks of gestation. We analyzed the association between TT-ratio and SGA adjusted to the week of gestation using logistic regression. Finally, we determined the possible TT-ratio cut-off point for discrimination between SGA and control groups by means of receiver operating characteristics (ROC) curve analysis. Results: The TT-ratio was significantly higher in the SGA group than in the control group (p < 0.001). An increase of the TT-ratio by 0.1 was associated with a 3.1-fold increase in the odds of diagnosing SGA. We determined that a possible discrimination cut-off point between SGA and healthy controls was achieved using a TT-ratio of 0.390 (area under the ROC curve 0.695). Conclusion: An increased TT-ratio may represent an additional prenatal screening parameter that improves the prediction of birth weight below the 10th percentile. Prospective studies are now needed to evaluate the use of fetal thymus size as predictive parameter for adverse fetal outcome. [ABSTRACT FROM AUTHOR]

To assess the influence of frame rate settings on longitudinal strain (LS) and mechanical synchrony (SYN) values in Speckle Tracking Echocardiography (STE) of healthy fetuses. In this prospective study, we collected transversal or apical four-chamber-views of 121 healthy fetuses between 20 and 38 weeks of gestation using three different frame rate (FR) settings (≥ 110, 100 ± 10, 60 ± 10 frames per second). We assessed the segmental and the global LS of both ventricles (2C) and of the left ventricle (LV) offline with QLab 10.8 (Philips Medical Systems, Andover, MA, USA). Inter- and intraventricular SYN were calculated as time difference in peak myocardial strain between the mid-segments of left and right ventricle (interventricular, 2C_Syn) and lateral wall and septum of the left ventricle (intraventricular, LV_Syn), respectively. In 84.3% STE was feasible at all three FR settings. The LS increased in both views at higher FRs to a statistically noticeable extent. SYN measurements and the absolute differences at patient level between the FR settings showed no statistically noticeable alterations. STE is feasible at low and high FR settings. SYN emerges to be a robust parameter for fetal STE as it is less affected by the FR. High FRs enable high temporal resolutions and thus an accurate examination of fetal hearts. Future research for the technical implementation of tailored fetal STE software is necessary for reliable clinical application. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the second trimester thymus-thorax-ratio (TTR) between fetuses born preterm (study group) and those born after 37 weeks of gestation were completed (control group). This study was conducted as a retrospective evaluation of the ultrasound images of 492 fetuses in the three vessel view. The TTR was defined as the quotient of a.p. thymus diameter and a.p. thoracic diameter. Fetuses that were preterm showed larger TTR (p<0.001) the second trimester than those born after 37 weeks of gestation were completed. The sensitivity of a binary classifier based on TTR for predicting preterm birth (PTB) was 0.792 and the specificity 0.552. In our study, fetuses affected by PTB showed enlarged thymus size. These findings led us to hypothesize, that inflammation and immunomodulatory processes are altered early in pregnancies affected by PTB. However, TTR alone is not able to predict PTB. [ABSTRACT FROM AUTHOR]

Objective: To reveal the effect of a maternal human immunodeficiency virus (HIV) infection on the fetal thymus size. Methods: The sonographic fetal thymus size was measured retrospectively in 105 pregnancies with maternal HIV infection and in 615 uncomplicated singleton pregnancies. The anteroposterior thymic and the intrathoracic mediastinal diameter were determined in the three-vessel view and their quotient, the thymic-thoracic ratio (TT ratio), was calculated. The study group was subdivided into three groups by the maternal viral load on the date of ultrasound (<50 cop./mL, 50–1000 cop./mL, >1000 cop./mL). Furthermore, an association between prognostic factors of the HIV infection such as the lymphocyte count, CD4/CD8 ratio, HIV medication and the thymus size, was investigated using correlation analyses. Results: Fetal thymus size in pregnancies of HIV-positive mothers showed to be noticeably larger than in uncomplicated pregnancies. The mean TT ratio in the HIV-positive group was 0.389 and in the control group 0.345 (P < 0.001). There was no association between any maternal HIV parameter or medication and the size of the thymus gland. Conclusion: Maternal HIV infection was associated with an increased fetal thymus size. Further consequences of intrauterine HIV exposure for fetal outcome and the development of the immune system of HIV-exposed uninfected (HEU) infants must be discussed. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to compare Philips and TomTec two-dimensional speckle tracking echocardiography (2D-STE) software measurements of strain and dyssynchrony values in healthy fetuses. Methods: This was an explorative observational study in which the echocardiographic data of 93 healthy fetuses between the 20th and 38th week of gestation were determined from a four-chamber view using 2D speckle tracking. The global and segmental longitudinal strain values of both ventricles, inter-ventricular and left intra-ventricular dyssynchrony were analyzed using QLab version 10.8 (Philips Medical Systems, Andover, MA, USA) and TomTec-Arena version 2.30 (TomTec, Unterschleißheim, Germany). Results: TomTec showed persistently lower values for all of the assessed strain and dyssynchrony variables. For all variables, the bias between vendors tended to increase with gestational age, though not to a significant extent. Left ventricular dyssynchrony and longitudinal strain within the mid segment of the septum correlated best between vendors; however, the limits of agreement were wide in both cases. None of the variables assessed in the two-chamber view compared well between QLAB and TomTec. Conclusion: Speckle tracking software cannot be used interchangeably between vendors. Further investigations are necessary to standardize fetal 2D-STE. [ABSTRACT FROM AUTHOR]

Background: The purpose of our study was to quantify the fetal myocardial function in pregnant women with diabetic diseases (FDM) and in normal controls (FC) using speckle tracking echocardiography (STE). Methods: In this prospective study, the myocardial strain and dyssynchrony were analyzed using STE in a transversal four-chamber view in 180 fetuses (53 FDM, 127 FC) between 19 and 39 weeks of gestation. The measurements of the global and segmental longitudinal strain of both chambers (2C) and of the single left chamber (1C) were executed offline via QLab 10.5 (Philips Medical Systems, Andover, MA, USA). We assessed dyssynchrony as the time difference between peaks in strain in the mid segments of both chambers (interventricular dyssynchrony, 2C_DYS) and of the single left chamber (intraventricular dyssynchrony, 1C_DYS). Results: Measurements were feasible with a high median frame rate of 199 frames/s (1st quartile: 174, 3rd quartile: 199). The global and segmental myocardial longitudinal strain of 2C and 1C were decreased and 2C_DYS and 1C_DYS were increased in pregnancies with diabetes compared to normal controls. Conclusion: Our study demonstrates that fetal hearts affected by maternal diabetes mellitus (DM) show low myocardial strain values and high interventricular dyssynchrony. Two-chamber interventricular dyssynchrony has the potential to become a diagnostic marker for DM. [ABSTRACT FROM AUTHOR]

Objective: To evaluate segmental left (LV-S) and right (RV-S) ventricular strain as well as longitudinal mechanical myocardial dyssynchrony as a time difference between peaks in strain of both ventricles in fetuses (two-chamber-dyssynchrony, 2C-DYS) using speckle tracking echocardiography (STE). The aim of our study was to evaluate the influence of data acquisition on the results of STE measurement using different ultrasound probes. Methods: We prospectively recorded cardiac cycles of four-chamber views of 56 normal fetuses with three different ultrasound probes and analyzed them offline with speckle tracking imaging software. Furthermore, we looked at a possible influence of heartbeat variability (beat-to-beat variability). Results: The evaluation of the parameters was feasible with all three probes in 53 cases. There was no influence of heartbeat variability and no noticeable differences in 2C-DYS, LV-S and RV-S in all cases and for all three probes determined. Conclusion: Assessment of strain and dyssynchrony using STE with three different probes is comparable. Further research is needed to validate dyssynchrony as a predictor for fetal outcome. [ABSTRACT FROM AUTHOR]

Purpose:  To evaluate cervical elastography strain pattern as a predictive marker for spontaneous preterm delivery (SPTD)., Materials and Methods:  In this case-control study cervical length (CL) and elastographic data (strain ratio, elastography index, strain pattern score) were acquired from 335 pregnant women (20th - 34th week of gestation) by transvaginal ultrasound. Data of 50 preterm deliveries were compared with 285 normal controls. Strain ratio and elastography index were calculated by placing two regions of interest (ROIs) in parallel on the anterior cervical lip. The strain ratio was determined by dividing the higher strain value by the lower one. The elastography index was defined as the maximum of the strain ratio curve. Elastographic images were assigned a new established strain pattern (SP) score between 0 and 2 according to the distribution of strain induced by compression., Results:  Elastography index, SP score and CL differed between preterm and normal pregnancies (1.61 vs. 1.27, p < 0.001; SP score value of "2": n = 31 (62 %) vs. n = 36 (12.6 %), p < 0.001; CL 30.7 vs. 41.0 mm, p < 0.001; respectively). The elastography index and SP score were associated with a higher predictive potential than CL measurement alone (AUC 0.8059 (area under the curve); AUC 0.7716; AUC 0.7631; respectively). A combination of all parameters proved more predictive than any single parameter (AUC 0.8987; respectively)., Conclusion:  Higher elastography index and SP scores were correlated with an elevated risk of SPTD and are superior to CL measurement as a predictive marker. A combination of these parameters could be used as a "Cervical Index" for the prediction of SPTD., Competing Interests: The authors declare that they have no conflict of interest., (© Georg Thieme Verlag KG Stuttgart · New York.)