Fetal cardiac structure and function as studied by ultrasound.

Present combined two-dimensional real-time and M-mode echocardiograph systems allow detailed analysis of fetal cardiac structure and function. Standard scanning planes for systematic investigation of various cardiac structures are described. There is a curvilinear increase in left ventricular volume (Qlv), stroke volume (Qlvs), and output Q'lv) during the last trimester of pregnancy with a mean Q'lv value at term of 126 +/- 11 ml/kg/min. Scanning for cardiac defects should preferably be done between 18 and 24 weeks of gestation. In a total of 444 patients referred to our ultrasound unit for ultrasonic analysis of fetal cardiac structure, a total of 13 cardiac defects were diagnosed. The incidence of structural cardiac defects present among those with fetal dysrhythmia was 15%.