Third Trimester Fetal Cardiac Blood Flow and Cardiac Outcomes in School‐Age Children Assessed By Magnetic Resonance Imaging

BACKGROUND: An adverse fetal environment leads to fetal hemodynamic adaptations with cardiac flow alterations that may subsequently affect cardiac development. We examined the associations of third trimester placental and fetal cardiac hemodynamics with cardiac outcomes in school‐age children. METHODS AND RESULTS: We performed a population‐based prospective cohort study among 547 mothers and their children. At a gestational age of 30.4 (95% range 28.4–32.7) weeks, we measured umbilical and cerebral artery resistance, cardiac output, and tricuspid and mitral E/A waves with Doppler. At the median age of 10.0 years (95% range 9.4–11.7) we measured cardiac outcomes with cardiac magnetic resonance imaging. Cardiac outcomes included right ventricular end‐diastolic volume) and right ventricular ejection fraction, left ventricular end diastolic volume and left ventricular ejection fraction, left ventricular mass, and left ventricular mass‐to‐volume ratio as left ventricular mass/left ventricular end diastolic volume. Higher third‐trimester umbilical artery resistance was associated with higher childhood right ventricular ejection fraction (P value <0.05), but not with other cardiac outcomes. The third‐trimester umbilical artery‐cerebral artery pulsatility index ratio was not associated with childhood cardiac outcomes. Higher third‐trimester fetal left cardiac output was associated with lower childhood left ventricular ejection fraction and higher left ventricular mass‐to‐volume ratio (P value <0.05). Third‐trimester fetal right cardiac output was not associated with childhood cardiac outcomes. A higher third‐trimester fetal tricuspid valve E/A ratio was associated with higher childhood right ventricular ejection fraction (P value <0.05). CONCLUSIONS: Our findings suggest that fetal cardiac fetal blood flow redistribution may have long‐term effects on cardiac structure and function. These results should be considered as hypothesis generating and need further replication.