Peculiarities of prevalence and morphology of congenital heart disease detected in utero.

Intrauterine echocardiography is changing our knowledge of congenital heart disease; cardiac defects diagnosed in utero have distinctive features of both prevalence and morphology when compared with those observed just after birth. We reviewed a series of 171 fetal heart conditions: 148 were diagnosed at intrauterine echocardiography, the diagnosis being verified at autopsy in 41, and 23 were observed at the postmortem only. Peculiarities of prevalence consisted in an excess of various defects, such as hypoplastic left heart syndrome, atrial isomerism, pulmonary atresia, and atrioventricular and atrial septal defects, and in a reduced number of completely different conditions, such as transposition of great arteries and aortic coarctation. Differences in prevalence have been attributed to difficulties in diagnosing some particular anomalies in utero, to the selection of pregnancies undergoing screening, and to the special intrauterine evidence of some heart defects. Peculiarities in morphology result from the coexistence with extracardiac malformations, from the changes in shape conditioned by fetal hemodynamics, and from the intrauterine evolution of the morphology of some malformations. We concluded that the knowledge of these characteristic traits was helpful to cardiac pathologists, pediatric cardiologists, and obstetricians, and allowed the re-evaluation of the role of hemodynamic factors in remodeling the malformed cardiovascular appara-tus.