Real time ultrasonic evaluation of the fetal heart

A series of measurements of cardiothoracic ratios (C/T) at various gestational ages are reported. Thirty fetuses ranging from 16 to 36 weeks gestational age were studied using real time ultrasonography. The cardiothoracic ratio remained constant regardless of gestational age. A case report is presented in which a congenital heart malformation was detected in utero using real time ultrasonography, illustrating the value of these measurements in selected cases.