Gestational age‐ and estimated fetal weight‐adjusted reference ranges for myocardial tissue Doppler indices at 24–41 weeks' gestation

OBJECTIVES: To construct gestational age (GA)- and estimated fetal weight (EFW)-adjusted reference ranges for tissue Doppler cardiac function parameters from 24 to 41 weeks' gestation. METHODS: This was a prospective cross-sectional observational study involving 213 singleton pregnancies between 24 and 41 weeks' gestation. Myocardial peak velocities and myocardial performance index (MPI') were measured by tissue Doppler ultrasonography (values indicated by 'prime') in the left and right annulus and interventricular septum. Left and right atrioventricular parameters were also measured by conventional Doppler and ratios between the values found by the two methods calculated. Regression analysis was used to determine GA- and EFW-adjusted reference ranges and to construct nomograms for tissue Doppler parameters. RESULTS: All myocardial peak velocities, left and right E'/A' and left MPI' showed a progressive increase with GA. In contrast, left and right E/E' showed a progressive decline. Septal E'/A', and right and septal MPI' remained constant. Myocardial peak velocities showed a progressive increase with increasing fetal weight. CONCLUSIONS: Normal data of fetal myocardial peak velocities, their ratios and MPI' by tissue Doppler adjusted by GA and EFW are provided. The reported reference values may be useful in research or clinical studies and can be used in fetuses with intrauterine growth restriction.