Nomograms of Fetal Cardiac Dimensions at 18–41 Weeks of Gestation

Abstract

Objective: There is a need for standardized reference values for cardiac dimensions in prenatal life. The objective of the present study was to construct nomograms for fetal cardiac dimensions using a well-defined echocardiographic methodology in a low-risk population. Methods: This is a prospective cohort study including 602 low-risk singleton pregnancies undergoing a standardized fetal echocardiography to accurately assess fetal cardiac, ventricular, and atrial dimensions. Parametric regressions were tested to model each measurement against gestational age from 18 to 41 weeks of gestation. Results: Nomograms were constructed for fetal cardiac dimensions (transverse and longitudinal diameters and areas) of the whole heart, atria, and ventricles, as well as myocardial wall thicknesses. All dimensions showed a progressive increase with gestational age. The best model for most parameters was a second-degree linear polynomial.Fetal cardiac, ventricular, and atrial diameters and areas were successfully obtained in 98.6% of the fetuses, while myocardial wall thicknesses could be obtained in 96.5% of the population. The results showed excellent interobserver and intraobserver reproducibility (intraclass correlation coefficient, ICC > 0.811 and ICC > 0.957, respectively). Conclusions: We provide standardized and comprehensively evaluated reference values for fetal cardiac morphometric parameters across gestation in a low-risk population. These nomograms would enable the early identification of different patterns of fetal cardiac remodeling.

Main Patterns of Fetal Cardiac Remodeling

“…The description of patterns provided here may help in the evaluation of cardiac remodeling. Such assessment is now easier since nomograms for most cardiac dimensions have recently been published [21,22,33]. A precise description of the morphological changes in the fetal heart may help comparison among research studies and contributes to understanding the pathophysiology of cardiovascular changes occurring under various pregnancy conditions (i.e., placental insufficiency, exposure to toxics, assisted reproductive technologies, valve stenosis).…”

“…Fetal 2D echocardiography has demonstrated to be highly feasible and reproducible for assessing fetal cardiac structure and shape when a standardized and strict methodology is followed ( Fig. 1) [21,22]. An apical or basal four-chamber view permits the measurement of cardiac, ventricular, and atrial dimensions (diameters and areas) and shape (sphericity by dividing longitudinal per transverse diameters) using specific landmarks.…”

“…Most cardiac and ventricular parameters are standardized to be measured at end-diastole (at maximal ventricular distension at the frame when the atrioventricular valves close), while atrial dimensions are usually recommended to be as- sessed at end-systole (maximal atrial distension just before the opening of atrioventricular valves). Standard criteria and nomograms for most fetal cardiac dimensions throughout gestation are available using standard 2D echo [21,22] and also a novel application of speckle tracking echocardiography [23]. Despite no actual consensus, patterns of cardiac remodeling in fetal life are usually described reporting cardiac, ventricular, and atrial areas, ventricular sphericity indices, septal wall thickness, and relative wall thickness adjusted by gestational age or estimated fetal weight ( Table 1).…”

Fetal Cardiac Remodeling Is Affected by the Type of Embryo Transfer in Pregnancies Conceived by in vitro Fertilization: A Prospective Cohort Study

“…Cardiac measurements were obtained from 2-dimensional images of the 4-chamber view with an angle of 45°-90° between the interventricular septum and the ultrasound beam according to a previously reported technique [24][25][26][27]. Images were optimized to enhance the borders of cardiac walls and cine clips were stored.…”

Biomechanics of Human Fetal Hearts with Critical Aortic Stenosis

“…We estimated the thickness of the aortic and mitral valves of fetal heart by first obtaining literature value of newborn heart valve leaflet thicknesses, 44 and then scaling them down assuming a direct linear relationship with cardiac diameter. 19 Thickness values used were 0.25 and 0.27 mm for the mitral and aortic valves. These thickness values were then assumed to be the axial length of the stenotic / regurgitant valve orifices.…”