Objective:To investigate the clinical value of fetal heart quantification (Fetal HQ) technology in evaluating fetal cardiac geometric remodeling and right ventricular systolic functional alterations in hypertensive disorders of pregnancy (HDP), and to assess its utility in identifying subclinical fetal myocardial impairment associated with HDP.Methods:This study prospectively enrolled 135 fetuses from pregnant women with HDP who underwent prenatal ultrasound examinations at the First Affiliated Hospital of Soochow University between March 2021 and September 2024, along with 135 gestational age-matched normal fetuses from routine prenatal examinations as controls. Thirty patients with chronic hypertension were excluded from the HDP group, resulting in a final cohort of 105 cases, which were subdivided into three subgroups: gestational hypertension (GH, n=39), mild preeclampsia (mPE, n=26), and severe preeclampsia (sPE, n=40). Fetal HQ software was employed to analyze standard four-chamber view dynamic videos, yielding the global spherical index (GSI), left and right ventricular end-diastolic areas, global longitudinal strain (GLS), fractional area change (FAC), and left ventricular ejection fraction (LVEF), as well as 24-segment end-diastolic diameter (EDD), spherical index (SI), and fractional shortening (FS). Intergroup differences in cardiac parameters between the HDP and control groups were compared using the independent samples t-test or Mann-Whitney U test, while comparisons among the three HDP subgroups were performed using one-way ANOVA or the Kruskal-Wallis H test. The Bonferroni correction was applied for global parameters, and the Benjamini-Hochberg method was used for segment-specific parameters. Intra- and inter-observer measurement consistency was assessed using the intraclass correlation coefficient (ICC).Results:Compared with the control group, the HDP group exhibited a significantly lower GSI [1.11 (1.08, 1.14) vs 1.13 (1.10, 1.17), adjusted P＜0.05]. Segmental SI was also significantly decreased in left ventricular segments 1-4 and 8-12, as well as in right ventricular segments 1-2 (all adjusted P＜0.05), with more extensive involvement observed in the left ventricle. No significant differences were found between the two groups in left ventricular global systolic function parameters, including GLS, FAC, and LVEF (all adjusted P＞0.05). However, right ventricular FAC was significantly reduced in the HDP group [(36.06±6.24)% vs (38.09±5.66)%, adjusted P＜0.05], and FS was widely decreased in right ventricular segments 3-24 (all adjusted P＜0.05). Repeatability analysis demonstrated that the ICCs for global parameters ranged from 0.776 to 0.997, and most segmental parameters exhibited ICCs ≥ 0.85. Subgroup analysis, after adjustment for gestational age, revealed no significant differences in GSI or mean right ventricular FS among the GH, mPE, and sPE groups (both adjusted P＞0.05).Conclusion:Fetuses of mothers with HDP demonstrate characteristic non-uniform cardiac geometric remodeling and right ventricle-dominant systolic dysfunction. The multi-parameter analysis integrating geometric remodeling and segmental functional parameters via Fetal HQ technology facilitates the detection of subclinical fetal myocardial involvement and offers a novel perspective for the objective quantification of HDP-related fetal cardiac changes.