To use the fetal heart quantification (Fetal HQ) technique to evaluate the morphology and systolic function of the normal fetal heart, and to explore the application value of this technique in evaluating fetal heart function.

From February 2021 to March 2022, 230 normal singleton pregnant women underwent ultrasound examination at the Functional Examination Department of the Maternity Center of the General Hospital of Ningxia Medical University and the Ultrasound Department of Ningxia Women's and Children's Hospital, Beijing University First Hospital (Ningxia Hui Autonomous Region Maternal and Child Health Hospital). Fetal HQ technique was used to quantitatively obtain the four-chamber end-diastolic length (L), transverse width (TW), heart area (A), and left and right ventricular A and L of 230 normal fetuses and to evaluate the size of the whole fetal heart and left and right ventricles. The global spherical index(GSI) and the spherical index (SI) of the 24 segments of the left and right ventricle were measured to evaluate the fetal heart shape. Fraction area change (FAC), global longitudinal strain (GLS), left ventricular ejection fraction (LVEF), and fractional shortening (FS) of the 24 segments of the left and right ventricles were measured to evaluate left and right ventricular systolic function, and the z values corresponding to each parameter were provided after gestational age correction, and the normal range was set at -2~2.

There was a linear correlation between fetal four-chamber end diastolic L (r=0.901, P＜0.001), TW (r=0.911, P＜0.001), and A (r=0.930, P＜0.001) and gestational age. The ED-A and ED-L of the left ventricle were significantly larger than those of the right ventricle (P＜0.05). There was no significant correlation between fetal four-chamber end diastolic GSI and SI of the 24 segments of the fetal left and right ventricle and gestational age (P＞0.05). When comparing the SI of the 24 segments between the fetal left ventricle and right ventricle, the differences in segments 1-17 and 19-24 were statistically significant (P＜0.05), while the differences in the 18th segment were not statistically significant (P＞0.05). The average fetal LVEF was (52.79±1.28)%. There was no significant correlation between FAC, GLS, and FS of the 24 segments of the fetal left and right ventricle and gestational age (P＞0.05). The FAC and GLS of the fetal left ventricle were significantly larger than those of the right ventricle (P＜0.05). When comparing the FS of the 24 segments of the fetal left ventricle with that of the right ventricle, there was no statistical difference in segments 1-3 (P＞0.05), but there was a statistical difference in segments 4-24 (P＜0.05). The average Z values corresponding to SI and FS in the 24 segments were all within the normal range.

Fetal HQ technique can provide multiple parameters to quantitatively analyze the size, shape, and systolic function of the fetal heart, with reliable and feasible results, which provides a new and effective method for evaluating fetal heart function.