Prenatal diagnosis of epidermolysis bullosa letalis.

The prenatal diagnosis of epidermolysis bullosa letalis was made by electron microscopy of a biopsy specimen of fetal skin taken under direct vision by fetoscopy at 18 weeks' gestation. The diagnosis was confirmed after termination of pregnancy. Abnormalities were found in the number, size, and scanning-electron-microscope appearance of amniotic-fluid cells. These techniques have considerable potential for rapid diagnostic studies in a number of other conditions.