Quantification of Z-scores of aortic and pulmonary diameters in normal fetuses using fetal echocardiography

Abstract

Objective To establish detailed quantitative comparison of cardiac vessel diameters with non-cardiac biometrical measurements and develop computation of Z-scores reference ranges of aortic and pulmonary diameters in normal fetuses.Methods A retrospective cross-sectional study of 1218 singleton normal fetuses was performed.Non-cardiac fetal biometric parameters included biparietal diameter (BPD) and femoral length (FL) and an assessment of gestation age (GA) based on menstrual age.Fetal cardiac measurements of aortic (AO) and pulmonary valve annulus diameters (PA) at end-systole were analyzed.Normal Z-score ranges were developed for AO and PA using GA,BPD and FL as independent variables.Results Linear regression models between AO,PA and three independent variables (BPD,FL,GA) were established,correlations between fetal cardiac measurements and the independent variables were excellent.Standard deviation (SD) for assessment of heteroscedastieity of independent variables also could be modeled with a simple linear regression by using weighted regression of absolute residuals in order to minimize the effect of heteroscedasticity.Conclusions By applying statistical computations that are based on a correlation of non-cardiac biometrical measurements including FDL,BPD and GA between fetal echocardiographic parameters as AO and PA,development of fetal Z-scores reference ranges for AO and PA was realized.This permits detailed assessment of growth of developing fetal cardiac structures in normal hearts and potentially allows for the quantitative assessment of the congenitally complex heart defects that severely alter cardiac dimensions. Key words: Echocardiography; Fetal heart ; Developmental biology; Pulmonary artery; Aorta