Comprehensive functional cardiac assessment of healthy fetuses at ≥ 37 weeks' gestation: A prospective study to establish normal values

Abstract Title: Comprehensive functional cardiac assessment of healthy fetuses at ≥ 37 weeks' gestation: A prospective study to establish normal values Background: Assessment of fetal cardiac function is an important part of fetal echocardiography. In daily routine fetal contractility is often assessed subjectively. In the last decade, advanced technologies such as speckle tracking have been developed to provide a more objective assessment of fetal heart function. However, studies using these technologies focused on fetuses in the second and early third trimesters. Little is known about fetal cardiac function at term and normal values based on larger cohorts at this gestational age are lacking. Therefore, the aim of this large prospective cross-sectional study is to perform a comprehensive fetal cardiovascular assessment and to establish normal values for fetal cardiac function measurements at ≥ 37 weeks' gestation. Methods: We conducted a prospective cross-sectional study at a tertiary referral centre, the Charité University Hospital in Berlin, Germany. Fetuses of mothers without pregnancy complications such as diabetes, pre-eclampsia or fetal growth restriction were included. Patient characteristics were derived from medical records. In addition, 4-chamber view cine loops were recorded and analysed using FetalHQ software, providing the following cardiac parameters: Global longitudinal strain, fractional area change, basal apical length fractional shortening, global sphericity index, MAPSE (mitral annular plane systolic excursion), TAPSE (tricuspid annular plane systolic excursion). Inflow Doppler, MPI and ventricular thickness were also recorded. The study protocol was approved by the local ethics committee. Statistical analysis was performed with SPSS. Results: Fetal cardiac measurements at term showed no significant correlation with gestational age or estimated fetal weight in the time period >37 weeks. Percentiles were calculated for each cardiac parameter. Conclusion: This study established normal values for cardiac function measurements for fetuses >37 weeks using the software FetalHQ. Normal values are essential in clinical routine to differentiate between normal and pathological.