Size and Shape of the Four-Chamber View of the Fetal Heart in Fetuses with an Estimated Fetal Weight Less than the Tenth Centile

Abstract Background Fetuses with an estimated fetal weight (EFW) th centile have an increased risk for adverse perinatal and long-term outcomes as well as increased rates of cardiac dysfunction which often alters cardiac size and shape of the 4-chamber view and the individual ventricles. As a result, a simple method has emerged to screen for potential cardiac dysfunction in fetuses with EFWs th centile by measuring the size and shape of the 4-chamber view (4CV) and the size of the ventricles. Objective Determine the number of fetuses with an abnormal size and shape of the 4CV and size of the ventricles in fetuses with an EFW th centile. Study Design This was a retrospective study of 50 fetuses between 25 and 37 weeks of gestation with an EFW th centile. Data from their last examination were analyzed. From an end-diastolic image of the 4CV the largest basal-apical length and transverse width were measured from their corresponding epicardial borders. This allowed the 4CV area and global sphericity index (4CV length/4CV width) to be computed. In addition, tracing along the endocardial borders with speckle tracking software enabled measurements of the right and left ventricular chamber areas and the RV /LV area ratios to be computed. Doppler waveform pulsatility indices from the umbilical (UAPI) and middle cerebral arteries (MCAPI) were analyzed, and the cerebroplacental ratio (CPR) computed (MCAPI/UAPI). UAPIs > 90 th and CPRs th % were considered abnormal. Using data from the control fetuses, the centile for each of the cardiac measurements was categorized by whether it was th or >90 th centile, depending upon the measurement. Results Of the 50 fetuses with EFWs th centile, 50% (N=25) had a normal UAPI and CPR. These fetuses had significantly more (P 90 th centile, 32% had a 4CV global sphericity index th centile, 56% had a 4CV width >90 th centile, and 80% had one or more abnormalities of size and/or shape. The remaining 50% of fetuses (N=25) had abnormalities of one or both for the UAPI and/or CPR. These fetuses had significantly higher rates of abnormalities (P 90 th centile; 28% had a 4CV global sphericity index th centile; 68% had a 4CV width >90 th centile. Only those with an abnormal UAPI had significant changes in ventricular size; 56% had a LV area th centile; 28% had a RV area th centile; 36% had RV/LV area ratio >90 th centile. One or more of the above abnormal measurements were present in 92% of fetuses. Conclusions Higher rates of abnormalities of cardiac size and shape of the 4CV were found in fetuses with EFW th centile, regardless of their UAPI and CPR measurements. Those with a normal UAPI and abnormal CPR had larger and wider measurements of the 4CV. In addition, the shape of the 4CV was more globular or round than controls. These fetuses may have an increased risk for perinatal complications and childhood and/or adult cardiovascular disease. Screening tools derived from the 4CV, acting as surrogates for ventricular dysfunction, may identify fetuses who could benefit from further comprehensive testing and future preventive interventions.