Evaluation of fetal heart function using fetal speckle-tracking echocardiography: Korean multicentre prospective study

To evaluate normal values of fetal heart function using fetal speckle-tracking echocardiography, which is suitable for Korean fetuses, and to evaluate the differences in fetal heart function of fetal growth restriction (FGR), maternal gestational diabetes mellitus (GDM), and fetal heart anomaly groups from the normal group. This multicentre prospective cohort study for normal values was conducted with 639 single pregnant women from Jan 2021 to Dec 2021 in 9 tertiary referral hospitals in Korea. Pregnant women underwent comprehensive fetal echocardiography using Fetal HQ® software from 20 to 41 weeks of gestation. To evaluate the difference in fetal heart function of FGR, GDM, and fetal heart anomaly, we collected additional data from Jan 2023 to Feb 2023. We tested 23 FGR, 12 GDM, and 24 fetal heart anomalies and compared them with normal fetuses. We evaluated the fetal cardiac, atrial, ventricular size and shape, and ventricular contractility. For normal values of Korean fetuses, Global cardiac length, width, and area were increased throughout gestation. Left and Right ventricular end-diastolic area (EDA) and end-systolic area (ESA) were increased with gestational age. Left and right ventricular contractility using fractional area change (FAC) and ejection fraction were not changed throughout gestational age but Left ventricular stroke volume was increased along with gestational age. In the FGR and maternal GDM group, stroke volume and ejection fraction were revealed to be increased. Moreover, FGR groups showed higher right and left FAC than the normal group. There was no global cardiac length, width, or shape difference between abnormal and normal groups. It is useful to measure the fetal cardiac, atrial, ventricular size, sphericity, and ventricular contractility using speckle-tracking echocardiography to evaluate fetal heart function. This multicentre study will help establish a standardised resource for understanding fetal heart function.