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

Abstract

Introduction: The aim of the study was to establish normal reference values obtained by fetal speckle tracking analysis of the fetal heart between 17 and 24 weeks of gestation among Thai fetuses and compare the nomograms with previous studies. Methods: The 4-chamber view (4CV) 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 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 4CV and ventricles.