Fetal Cardiac Remodeling and Subclinical Myocardial Dysfunction in Pregnancies Complicated by Placenta Accreta Spectrum: A Prospective Echocardiographic Study.

To investigate the pattern of fetal cardiac remodeling and dysfunction associated with placenta accreta spectrum (PAS), a disorder characterized by abnormal placental angioarchitecture, and to test the hypothesis that PAS imposes a distinct hemodynamic burden on the fetal heart. This prospective case-control study included 50 singleton pregnancies diagnosed with PAS and 50 gestational age-matched uncomplicated pregnancies as controls. Comprehensive fetal echocardiography was performed to assess structural parameters-including right and left ventricular free wall thickness, interventricular septal thickness, and the cardiothoracic ratio-and functional parameters including the modified myocardial performance index (Mod-MPI), isovolumetric contraction time, isovolumetric relaxation time, and ejection time. Standard fetoplacental Doppler indices were also evaluated. Standard Doppler parameters, including the umbilical artery pulsatility index, did not differ between groups (p = .240). However, significant cardiac alterations were observed in the PAS group. Compared with controls, fetuses in the PAS group demonstrated thicker right ventricular free wall (4.59 ± 0.73 versus 4.21 ± 0.68 mm; p = .008) and interventricular septum (4.72 ± 0.47 versus 4.27 ± 0.83 mm; p = .001), as well as a higher cardiothoracic ratio (0.56 ± 0.06 versus 0.49 ± 0.04; p < .001). Functionally, the Mod-MPI was significantly increased in the PAS group (0.53 ± 0.07 versus 0.46 ± 0.08; p < .001), primarily driven by prolongation of the isovolumetric relaxation time (53.3 ± 7.74 versus 45.9 ± 10.35 ms; p = .001), consistent with impaired diastolic function. PAS is associated with a distinct fetal cardiac phenotype characterized by eccentric hypertrophy and diastolic dysfunction, compatible with a chronic volume-overload state. This remodeling occurs despite normal standard fetoplacental Doppler indices, suggesting that the low-resistance vascular architecture of PAS imposes a unique hemodynamic load on the fetal heart. Fetal echocardiography appears to be a sensitive tool for detecting this subclinical cardiac involvement, which may have implications for fetal programming and long-term cardiovascular health.