ERRORS AND PITFALLS IN PRENATAL-DIAGNOSIS OF CONGENITAL HEART-DISEASE

Objective: The aim is to elucidate the origin of some errors we made in the prenatal diagnosis of congenital heart disease in order to understand whether they could have been avoided. Methods: One thousand two hundred pregnant women were studied by means of two-dimensional echocardiography either alone or in association with pulsed and color Doppler. The patients were referred because of an increased risk of congenital heart disease or because of an abnormal four-chamber view at routine scanning. Results: The errors discussed concern: two cases (one of tricuspid atresia and one of critical aortic stenosis) in which a color Doppler flow pattern different from the expected one was found; two missed cases of mild pulmonary stenosis studied only by means of two-dimensional echocardiography; one case of pulmonary atresia studied only once at 18 weeks, without interrogating the pulmonary valve with pulsed Doppler-the cardiac malformation was diagnosed at postmortem examination at term; two cases of pulmonary atresia in which the prenatal diagnosis was severe pulmonary stenosis-the origin of the error is not the same in the two cases; 6/14 false negative diagnoses of interventricular septal defect. Conclusions: The errors are attributable to incorrect interpretation of the flow patterns and to the natural history of the disease. They may be avoided by performing a second examination at 30-32 weeks when the first one is done at 18-20 weeks. Errors are also attributable to the characteristics of the lesions along with the peculiarity of the fetal circulation. These will be the most difficult to overcome.