Quantitative two-dimensional echocardiographic assessment of fetal cardiac growth.

High-resolution, real-time cardiac imaging and Doppler measurements of blood flow have the potential of extending the fetal cardiovascular profile beyond heart rate monitoring alone. The development of normal standards is a prerequisite to the application of these capabilities. To quantify fetal cardiac growth and explore the potential applications, we performed real-time, two-dimensional echocardiography in a cross-sectional study of 75 normal pregnancies from 17 to 40 weeks gestation. Left and right ventricular, left and right atrial, and aortic root measurements were obtained. Regression analysis showed that the best correlation for ventricular and aortic dimensions with gestational age or biparietal diameter was a straight line (y = mx + b). Ten normal fetuses were then serially monitored. Cardiac dimensions fell within the confidence range of the regression models, and most cases exhibited similar growth slopes. Finally, five abnormal cases were studied to demonstrate the use of these data in diagnosing altered cardiac structure and function.