Fetal heart quantification ultrasound technology for the quantitative analysis of fetal cardiac morphology and function in hypertensive disorders of pregnancy

Abstract

Background: Hypertensive disorders of pregnancy (HDP) are associated with adverse outcomes for both the mother and fetus, including impaired fetal cardiac development and function. Accurate assessment of fetal heart morphology and function is essential for the early detection and management of potential complications. This study investigated the clinical application value of fetal heart quantification (Fetal HQ) technology in evaluating the cardiac morphology and function in fetuses from pregnancies affected by HDP.

Methods: This prospective study examined 43 fetuses from singleton pregnancies complicated by HDP [mean gestational age (GA) 29.5±2.8 weeks] and 50 fetuses from normal pregnancies (mean GA 29.2±2.4 weeks). All participants underwent fetal ultrasonography from August 2023 to July 2024. Fetal HQ technology, incorporating two-dimensional speckle-tracking echocardiography (2D-STE) with quantitative analysis of cardiac segments, was used to assess heart size, shape, ventricular structure, contractility, and function.

Results: The HDP group exhibited significantly altered maternal clinical characteristics, including higher maternal weight, BMI, and blood pressure. Fetal cardiac morphometry indicated that compared to the control group, the HDP group had larger left ventricular (LV) dimensions yet lower volumes but had smaller right ventricular (RV) dimensions. Notably, compared with the control group, the HDP group had a larger LV end-diastolic (ED) area (2.52±0.88 vs. 1.92±0.62 cm²; P<0.001) and ED length (2.35±0.37 vs. 1.89±0.33 cm; P<0.001) but a smaller LV ED volume (2.17±0.83 vs. 3.09±0.69 mL; P<0.001). Additionally, the HDP group exhibited significantly higher LV global strain (-30.53%±9.88% vs. -25.22%±8.33%; P=0.006), indicating altered cardiac function. The 24-segment analysis revealed notable alterations in ventricular geometry and function within the HDP group, with lower sphericity index (SI) and fractional shortening (FS) values across various segments of both ventricles. These findings closely align with the results of the Z score analysis, further highlighting the extent of cardiac dysfunction.

Conclusions: Fetal HQ technology effectively identified significant alterations in fetal heart structure and function in pregnancies complicated by HDP. These findings suggest that Fetal HQ is a useful tool for the early detection of fetal heart abnormalities and can facilitate timely intervention and accurate prognosis in affected pregnancies.

Keywords: Hypertensive disorders of pregnancy (HDP); fetal cardiac function; fetal cardiac morphology; fetal heart quantification technology (Fetal HQ technology); ultrasound imaging.

Figure 1

Study recruitment flowchart. Ctrl, control; HDP, hypertensive disorders of pregnancy.

Figure 2

Computation of GSI. For the measurement of the fetal cardiac GSI of mothers with HDP, a longitudinal line is drawn from the apex to the base of the cardiac outer edge, and a transverse line is drawn from the sidewall of the LV to the sidewall of the RV at the end of diastole. The GSI can be obtained by dividing the end-diastolic basal-apical length by the end-diastolic transverse width. A, area; C, circumference; ED, end-diastolic; GSI, global sphericity index; HDP, hypertensive disorders of pregnancy; LV, left ventricle; RV, right ventricle; 4CV, four-chamber view; L, left; ZS, Z score; TW, transverse width.

Figure 3

Determination of the cardiac cycle. This figure shows the determination of the right ventricular cardiac cycle, including end-diastolic and end-systolic.

Figure 4

A 24-segment speckle-tracking measurement by Fetal HQ analysis. The green lines delineate the endocardial borders of the ventricular walls, illustrating their morphology and dimensions for analysis. Fetal HQ, fetal heart quantification.

Figure 5

Comparison of ventricular 24-segment ED values between groups. *, P value <0.05. ED, end-diastolic; HDP, hypertensive disorders of pregnancy; LV, left ventricle; RV, right ventricle.

Figure 6

Comparison of ventricular 24-segment SI values between groups. *, P value <0.05. HDP, hypertensive disorders of pregnancy; LV, left ventricle; RV, right ventricle; SI, sphericity index.

Figure 7

Comparison of ventricular 24-segment FS values between groups. *, P value <0.05. FS, fractional shortening; HDP, hypertensive disorders of pregnancy; LV, left ventricle; RV, right ventricle.

Figure 8

Comparison of ventricular 24-segment FS Z score values between groups. *, P value <0.05. FS, fractional shortening; HDP, hypertensive disorders of pregnancy; LV, left ventricle; RV, right ventricle.