RESUMO
OBJECTIVE: Hemoglobin (Hb) Bart's disease is a severe manifestation of alpha thalassemia, resulting in fetal tissue hypoxia and severe anemia. There is limited research available on assessing fetal speckle tracking analysis as a response to fetal anemia caused by Hb Bart's disease and its utility as a sonographic predictor for Hb Bart's disease. This study aimed to assess the diagnostic performance of fetal cardiac parameters derived from speckle tracking echocardiography for distinguishing between affected and unaffected fetuses in pregnancies at risk of Hb Bart's disease during the 17-24 gestational weeks. METHODS: A total of 115 pregnant women at risk for fetal Hb Bart's disease, who underwent either amniocentesis or cordocentesis at Siriraj Hospital, Bangkok Thailand, were included. Speckle tracking analysis was performed on the 4-chamber view (4CV) of the fetal heart, assessing heart size, shape, ventricular contractility, and left ventricular function prior to invasive prenatal testing. Logistic regression analysis determined significant cardiac predictors and calculated the probability of a fetus having Hb Bart's disease. RESULTS: Among the cohort, 38 fetuses (33%) were diagnosed with Hb Bart's disease, and 9 cases (7.8%) exhibited frank hydropic signs. In comparison to the control group, affected fetuses displayed a notable enlargement of the 4CV and a more globular shape specifically in the right ventricular chamber. Additionally, there were significant differences in the left global and longitudinal contractility between affected and unaffected fetuses. However, at mid-gestation, no significant distinctions were observed in terms of transverse contractility and left ventricular function between the two groups. Based on logistic regression analysis, combined cardiac parameters derived from speckle tracking analysis as a function of head circumference, could differentiate non-hydropic fetuses with Hb Bart's disease from unaffected fetuses, achieving a maximum sensitivity of 100%, specificity of 98.7%, and overall accuracy of 99.06%. CONCLUSIONS: Speckle tracking echocardiography has the potential to accurately identify early fetal heart changes in individuals at risk of developing Bart's anemia during the second trimester. This not only offers a novel predictive marker for Hb Bart's disease but also helps address the question of the underlying mechanisms of heart failure associated with anemia. This article is protected by copyright. All rights reserved.
RESUMO
OBJECTIVES: To develop normative data for the left-atrial posterior-space-to-diagonal (LAPSD) ratio and post-left atrium space (PLAS) index in fetuses from 17 to 37 weeks' gestation, and determine the optimal cut-offs of the LAPSD ratio and PLAS index to discriminate between normal fetuses and those with total anomalous pulmonary venous connection (TAPVC). METHODS: This was a prospective cross-sectional assessment of 428 structurally normal fetuses between 17 and 37 weeks' gestation and a retrospective study of 27 TAPVC fetuses. The fetal LAPSD ratio was calculated by dividing the left atrium-descending aorta distance (LDD) by the left atrial diagonal diameter (LA). The PLAS index was calculated as the ratio of the LDD to the descending aorta diameter (DA). Pearson's correlation analysis was used to examine the correlation of cardiac parameters with gestational age (GA) and fetal somatic growth. The PLAS index and LAPSD ratio were compared between the normal and TAPVC groups to assess their usefulness in the prenatal diagnosis of TAPVC. RESULTS: LDD, LA and DA measures showed moderate to strong positive correlation, whereas both the LAPSD ratio and PLAS index showed a slight decrease with increasing GA and biometric variables. The fetal LAPSD ratio and PLAS index in TAPVC cases were significantly greater compared with those of fetuses with a normal heart (both P < 0.001). There were no significant differences in the PLAS index and LAPSD ratio between the isolated and complex TAPVC groups (both P = 1). No significant associations of the PLAS index and LAPSD ratio with fetal gender, four-chamber view type (apical, basal or lateral) or TAPVC type were found. Using values of ≥ 0.35 for the LAPSD ratio and of ≥ 1 for the PLAS index exhibited similar excellent diagnostic performance, with a sensitivity of 100% and specificity of 97.0% or 95.1% for detecting TAPVC. CONCLUSIONS: Our study demonstrates that the LAPSD ratio is a practical and effective screening tool for diagnosing fetal TAPVC, similar to the PLAS index. Incorporating these parameters into routine cardiac scanning may enhance the prenatal detection of TAPVC. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
