Echocardiographic evaluation of dilated cardiomyopathy in the human fetus.

The diagnosis of dilated cardiomyopathy was established and subsequently confirmed in 6 of 625 fetuses studied by echocardiography. All 6 had structurally normal hearts. Abnormal findings included reduced fractional shortening index in 5, atrioventricular valve regurgitation in 3, abnormal chamber dimensions in 3 and nonimmune hydrops in 4. In 2 fetuses referred because of a family history of dilated cardiomyopathy in previous siblings, echocardiographic abnormalities were absent on a first examination performed at 20 weeks of gestation. This suggested that a normal fetal echocardiogram in a midtrimester fetus does not always rule out the subsequent development of dilated cardiomyopathy. However, all fetuses followed serially developed some abnormality later in pregnancy. Only 2 neonates survived, 1 of whom required a heart transplant during infancy. Death from cardiac failure occurred in 1 fetus and 3 neonates. This study demonstrates that dilated cardiomyopathy may develop during fetal life and might be diagnosed by echocardiography if serial studies are performed. Dilated cardiomyopathy presenting prenatally appears to have a poor prognosis.