Prenatal diagnosis of atrioventricular canal malformations with up-to-date echocardiographic technology: report of 14 cases.

Fourteen fetuses with atrioventricular canal malformations were examined by two-dimensional echocardiography, pulsed-wave Doppler echocardiography, and color Doppler flow mapping. Eleven fetuses had complete and three fetuses had partial atrioventricular canal malformations. Nonimmune hydrops fetalis was associated with six cases, and fetal arrhythmia was seen in three cases. With two-dimensional echocardiography, the atrioventricular canal malformations could be diagnosed accurately. The inclusion of color Doppler flow mapping, however, provided additional hemodynamic information that was important from the prognostic point of view. Incompetence of atrioventricular valves could be demonstrated in 10 of 14 cases by Doppler echocardiography. In nine cases, detailed Doppler echocardiographic evaluation of the regurgitation jet was possible. The proportion of systolic time during which atrioventricular valve insufficiency was demonstrated was related to the occurrence of nonimmune hydrops fetalis. When insufficiency of atrioventricular valves was associated with hydrops (four cases), a pansystolic insufficiency was always present. In cases without hydrops (five), regurgitation was confined to early systole. Thus a reliable method for semiquantitative evaluation of the degree of insufficiency seems to have been found. Moreover, an association appeared to exist between the occurrence of hydrops fetalis and the proportion of atrial area that was taken up by regurgitant jet area, as determined by planimetry in the four-chamber view. Prenatal diagnosis was confirmed by autopsy or neonatal cardiac evaluation. Only one neonate survived in our series. Two were stillborn, four died during the neonatal period, two died during infancy, and pregnancy was electively terminated prematurely in five cases. Eight fetuses were found to have a karyotypic abnormality.