Evaluation of fetal cardiac morphology and function in the normal second and third trimester : application of the Fetal Heart Quantification technique

Abstract

Abstract Objective: Using the Fetal Heart Quantification technique to comprehend the fetal heart's changes in growth and development during the typical second and third trimesters, and provide a framework for the clinical use of the fetal heart speckle tracking technology. Methods: This study involved 500 fetuses from mothers who had normal pregnancies between March 2021 and August 2022. The fetal heart was analyzed quantitatively after the fetal ultrasound readings and a film of a typical four-chamber heart slice was recorded. Measurements included fetal heart size, GSI, SV, CO, EF, GLS, and FAC of both ventricles, as well as EDD, SI, and FS of 24 segments. The research subjects were divided into 5 groups according to the GA: 20~23+6, 24~27+6, 28~31+6, 32~36+6, 37~40+6 weeks. Continuous variables between groups were compared by single Factor analysis of variance or Kruskal-Wallis test, P<0.05 means the difference is statistically significant. Results: 1. The size parameters of ventricles gradually increased with increasing GA (P < 0.05). The 24 segments EDD of both ventricles increased with increasing GA (P < 0.05), while first increasing and then decreasing from the ventricle base to the apex. 2. The GSI and the 24 segments SI of the two ventricles were not significantly different among the groups (P > 0.05). 3. The left ventricular EF, GLS, FAC, and right ventricular GLS, FAC decreased with increasing GA, and SV and CO increased (P < 0.05). 4. The 24 segments FS of the left ventricle showed a downward trend with increasing GA and gradually increased from the base to the apex. The FS of most segments of the right ventricle decreased with increasing GA and first increased and then decreased from the base to the apex. Conclusions: The whole and segmental size parameters can quantitatively evaluate the growth and development of the fetal heart; the GSI and segmental SI are reliable morphological indexes; fetal ventricular function parameters EF, FAC, GLS, and segmental FS can assess cardiac function. The Fetal HQ technique can help us to evaluate the heart growth and development of normal fetuses in the second and third trimesters of pregnancy.