Normal fetal cardiac measurements derived by cross-sectional echocardiography.

Cardiac structures have been measured in normal fetuses by cross-sectional echocardiography to establish a range of normal values. Gestational ages varied from 16 weeks to term. The cardiac structures measured were left and right ventricular width (n = 337), aortic root diameter (n = 296), pulmonary artery diameter (n = 312), mitral valve orifice (n = 159), and tricuspid valve orifice (n = 161). The lengths of the left and right ventricles were measured in 100 fetuses. Normal ranges were constructed using real-time ultrasound images which can be readily used in routine practice. Measurement of cardiac structures is an aid to the study of cardiac abnormalities and the availability of normal ranges of measurements of fetal cardiac structures may help to confirm and define suspected cardiac malformation during routine screening.