Evolution of fetal subependymal cysts throughout gestation.

Subependymal cysts are secondary to brain germinal matrix hemorrhage or infarction and are associated with fetal chromosomal and metabolic conditions, as well as infections. They are found in 1-3% of neonates in the first days of life and have been described in fetuses, although much less frequently. We report the prenatal diagnosis of a case of subependymal cysts first visualized at 12 weeks' gestation and its evolution throughout pregnancy and after birth. As far as we know, this is the first time that such a condition is described before 16 weeks' gestation as well as its longitudinal evolution. Knowledge that subependymal cysts can be seen as early as 12 weeks' gestation and their natural evolution is important to avoid equivocal diagnoses. The prognosis of isolated subependymal cysts remains uncertain.