The Down syndrome in the fetus.

A significant number of fetuses with the Down syndrome are spontaneously lost before birth; however, very few such fetuses have been described. In the present study, 13 fetuses of 127--180 mm in crown-rump length were examined following amniocentesis diagnosis of trisomy 21 and therapeutic abortion. Four features, i.e., simian crease, clinodactyly, septal heart defects, and decreased size, were found to be relatively common in trisomy 21 fetuses as compared to controls. Other features were found to be less useful in identification. We conclude that the presence of two of the four features noted above is suggestive of trisomy 21 in the fetus.