The purpose of this pictorial review was to describe various echocardiographic techniques that can be used for the functional assessment of the fetal heart. The systolic and diastolic assessments of the fetal heart are presented separately, with an emphasis on 2-dimensional Doppler methods and an overview of new technologies. The aim of this summary was to review the tools that can be used by the echocardiographer, and on that basis, to systematize the process of performing a functional assessment.
Echocardiography ; Fetal Heart

Purpose: Fetal echocardiography is the primary diagnostic tool for assessing the atrioventricular (AV) time interval. Establishing a reference range for this parameter throughout pregnancy is essential for the early detection of potential abnormalities. The aim of this study was to develop a Z-score equation and establish specific percentiles for the AV time interval in normal fetuses between 16 and 33+6 weeks of gestation. Methods: A multicenter, prospective, cross-sectional study was conducted between 2018 and 2022. A large sample of pregnant women meeting specific eligibility criteria was included, while cases with potential confounders were excluded. Two-dimensional echocardiography with pulsed Doppler techniques was employed, focusing on the left ventricular inflow and outflow. Data were rigorously analyzed with careful assessment of measurements and normalization procedures. Results: In total, 1,309 echocardiograms were performed, and 1,183 pregnant women were included after applying the eligibility criteria. Detailed percentiles for each gestational age were determined, and a Z-score equation was formulated. A very weak correlation was observed between AV interval measurement and gestational age (r=0.16, P<0.001). In addition, the correlation between AV interval measurement and fetal heart rate was weak (r=-0.21, P<0.001). The Z-score for the AV interval measurement in milliseconds was derived as follows: Z-score=(AV interval measurement-111.3)/8.6. Conclusion This study provides a reference range and Z-score equation for the AV interval, which may enhance the accuracy of monitoring fetuses at risk for developing atrioventricular block—especially in pregnant women with specific antibodies—thus facilitating earlier diagnosis and treatment.

Purpose: Fetal echocardiography is the primary diagnostic tool for assessing the atrioventricular (AV) time interval. Establishing a reference range for this parameter throughout pregnancy is essential for the early detection of potential abnormalities. The aim of this study was to develop a Z-score equation and establish specific percentiles for the AV time interval in normal fetuses between 16 and 33+6 weeks of gestation. Methods: A multicenter, prospective, cross-sectional study was conducted between 2018 and 2022. A large sample of pregnant women meeting specific eligibility criteria was included, while cases with potential confounders were excluded. Two-dimensional echocardiography with pulsed Doppler techniques was employed, focusing on the left ventricular inflow and outflow. Data were rigorously analyzed with careful assessment of measurements and normalization procedures. Results: In total, 1,309 echocardiograms were performed, and 1,183 pregnant women were included after applying the eligibility criteria. Detailed percentiles for each gestational age were determined, and a Z-score equation was formulated. A very weak correlation was observed between AV interval measurement and gestational age (r=0.16, P<0.001). In addition, the correlation between AV interval measurement and fetal heart rate was weak (r=-0.21, P<0.001). The Z-score for the AV interval measurement in milliseconds was derived as follows: Z-score=(AV interval measurement-111.3)/8.6. Conclusion This study provides a reference range and Z-score equation for the AV interval, which may enhance the accuracy of monitoring fetuses at risk for developing atrioventricular block—especially in pregnant women with specific antibodies—thus facilitating earlier diagnosis and treatment.

Purpose: Fetal echocardiography is the primary diagnostic tool for assessing the atrioventricular (AV) time interval. Establishing a reference range for this parameter throughout pregnancy is essential for the early detection of potential abnormalities. The aim of this study was to develop a Z-score equation and establish specific percentiles for the AV time interval in normal fetuses between 16 and 33+6 weeks of gestation. Methods: A multicenter, prospective, cross-sectional study was conducted between 2018 and 2022. A large sample of pregnant women meeting specific eligibility criteria was included, while cases with potential confounders were excluded. Two-dimensional echocardiography with pulsed Doppler techniques was employed, focusing on the left ventricular inflow and outflow. Data were rigorously analyzed with careful assessment of measurements and normalization procedures. Results: In total, 1,309 echocardiograms were performed, and 1,183 pregnant women were included after applying the eligibility criteria. Detailed percentiles for each gestational age were determined, and a Z-score equation was formulated. A very weak correlation was observed between AV interval measurement and gestational age (r=0.16, P<0.001). In addition, the correlation between AV interval measurement and fetal heart rate was weak (r=-0.21, P<0.001). The Z-score for the AV interval measurement in milliseconds was derived as follows: Z-score=(AV interval measurement-111.3)/8.6. Conclusion This study provides a reference range and Z-score equation for the AV interval, which may enhance the accuracy of monitoring fetuses at risk for developing atrioventricular block—especially in pregnant women with specific antibodies—thus facilitating earlier diagnosis and treatment.

Purpose: Fetal echocardiography is the primary diagnostic tool for assessing the atrioventricular (AV) time interval. Establishing a reference range for this parameter throughout pregnancy is essential for the early detection of potential abnormalities. The aim of this study was to develop a Z-score equation and establish specific percentiles for the AV time interval in normal fetuses between 16 and 33+6 weeks of gestation. Methods: A multicenter, prospective, cross-sectional study was conducted between 2018 and 2022. A large sample of pregnant women meeting specific eligibility criteria was included, while cases with potential confounders were excluded. Two-dimensional echocardiography with pulsed Doppler techniques was employed, focusing on the left ventricular inflow and outflow. Data were rigorously analyzed with careful assessment of measurements and normalization procedures. Results: In total, 1,309 echocardiograms were performed, and 1,183 pregnant women were included after applying the eligibility criteria. Detailed percentiles for each gestational age were determined, and a Z-score equation was formulated. A very weak correlation was observed between AV interval measurement and gestational age (r=0.16, P<0.001). In addition, the correlation between AV interval measurement and fetal heart rate was weak (r=-0.21, P<0.001). The Z-score for the AV interval measurement in milliseconds was derived as follows: Z-score=(AV interval measurement-111.3)/8.6. Conclusion This study provides a reference range and Z-score equation for the AV interval, which may enhance the accuracy of monitoring fetuses at risk for developing atrioventricular block—especially in pregnant women with specific antibodies—thus facilitating earlier diagnosis and treatment.

Purpose: Fetal echocardiography is the primary diagnostic tool for assessing the atrioventricular (AV) time interval. Establishing a reference range for this parameter throughout pregnancy is essential for the early detection of potential abnormalities. The aim of this study was to develop a Z-score equation and establish specific percentiles for the AV time interval in normal fetuses between 16 and 33+6 weeks of gestation. Methods: A multicenter, prospective, cross-sectional study was conducted between 2018 and 2022. A large sample of pregnant women meeting specific eligibility criteria was included, while cases with potential confounders were excluded. Two-dimensional echocardiography with pulsed Doppler techniques was employed, focusing on the left ventricular inflow and outflow. Data were rigorously analyzed with careful assessment of measurements and normalization procedures. Results: In total, 1,309 echocardiograms were performed, and 1,183 pregnant women were included after applying the eligibility criteria. Detailed percentiles for each gestational age were determined, and a Z-score equation was formulated. A very weak correlation was observed between AV interval measurement and gestational age (r=0.16, P<0.001). In addition, the correlation between AV interval measurement and fetal heart rate was weak (r=-0.21, P<0.001). The Z-score for the AV interval measurement in milliseconds was derived as follows: Z-score=(AV interval measurement-111.3)/8.6. Conclusion This study provides a reference range and Z-score equation for the AV interval, which may enhance the accuracy of monitoring fetuses at risk for developing atrioventricular block—especially in pregnant women with specific antibodies—thus facilitating earlier diagnosis and treatment.